Plant Disease Fact Sheet - WVU Ext

Transcription

Quick Reference
Pest Fact Sheets
Developed by:
Dr. John F. Baniecki, Professor and Extension Specialist
West Virginia University Extension Service
and
Jordan E. Eggers, Graduate Assistant, Plant and Soil Sciences
West Virginia University
and
David P. McCann, Graduate Assistant, Plant and Soil Sciences
For more information, please contact John Baniecki at:
G101 South Agricultural Science Building
Morgantown, West Virginia 26506
Office phone: (304) 293-88
E-mail: [email protected]
Quick Reference
Pest Fact Sheet
John F. Baniecki, Ph.D.
Jordan E. Eggers
David P. McCann, MS
Dear Reader,
Thank you for using West Virginia University Extension Service’s Quick Reference Pest Fact Sheets.
These fact sheets are intended to be used as supplemental aids in identifying plant disease
problems that are common to West Virginia growers and homeowners. The information presented is
organized by common plant types, i.e. corn, pepper, tomato, maple, etc. Tabs in the upper right
corner of each fact sheet designate plant type. Each fact sheet is composed of a short description
of symptoms, color images of signs and symptoms, the name of the disease and its cause, a short
description of conditions ideal for the disease to arise, and references. Numbers in the lower left
hand corners of the images correspond to the image’s citation which is found in the "Picture
Bibliography" located in the final pages of this document. The picture bibliography is organized in
the sequence in which the diseases are presented, i.e. tomato diseases, potato diseases, bean
diseases, etc. This document will be updated as more diseases are added. Any suggestions for
plant disease issues are greatly encouraged. To submit a suggestion or to comment on any aspect
of the fact sheets please contact Dr. John F. Baniecki at [email protected] or (304) 2938838 or contact your local WVU Extension agent.
This is a publication of the West Virginia University Extension Service.
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
David P. McCann, MS
Diseases
Jordan E. Eggers
Plant: Tomato
Symptoms
Leaves: Chocolate brown spots on leaves near soil (Image 1). These grow into larger spots with
rings that have a raised texture (Image 2). Leaves turn yellow around spots (Image 3). Spots can
be round or irregular shaped and ¼ to ½ inch in size. Multiple spots and grow together and form
larger spots. Stem: Chocolate brown spots with rings and a raised texture (Image 4). Fruit: Only
unripe fruit are affected. Dark sunken spots form from the stem down.
1
3
Disease: Early
2
4
Blight caused by Alternaria solani.
Disease development conditions? Two weeks after planting; need 80˚F temperatures and high
humidity.
References
Delahaut, K. and W. Stevenson. 2004. Tomato disorders: early blight and Septoria leaf spot. University of Wisconsin
Extension, Cooperative Extension Publishing. Disease fact sheet A2606.
Dixon, G.R. 1981. “Pathogens of solanaceous crops” in Vegetable Crop Diseases. AVI Publishing Company, Inc.
Westport, Connecticut.
Tomato
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Tomato
Symptoms
Leaves: Pale green water soaked spots starting at leaf tips turning into brown to purple-black
spots with yellow edges. White fuzz present on underside of leaves (Image 3). Leaves rot quickly
in moist conditions. Stems: Brown streaks along the stems (Image 2). Fruit: Infection spots on
unripe fruit are brown, firm, appear leathery, and usually start at the stem (Image 1).
1
3
2
Disease: Late
blight caused by Phytophthora infestans.
Disease development conditions? Mature, fruiting plants, infection requires a minimum of 3-4
days of high humidity (65-90% RH) with temperatures of 50-54.5˚F.
References
Dixon, G.R. 1981. “Pathogens of solanaceous crops” in Vegetable Crop Diseases. AVI Publishing Company, INC.
Rowe, R. C., S. A. Miller, and R. M. Riedel. 1995. Late blight of potato and tomato. Ohio State University Extension.
Extension Fact Sheet HYG-3102-95.
Tomato
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Pest Fact Sheet
Jordan E. Eggers
Plant: Tomato
Symptoms
Leaves: Small (1/16-1/4 inch), circular spots with tan or light colored centers and dark brown
borders on the leaf surface (Image 2) and water soaked spots on underside of leaf. Leaves often
yellow around spots (Image 3). Tiny black dots may be seen in tan centers (Image 1). Leaves
drop from the plant bottom up leading to a complete loss of leaves. Stems: May also have spots.
Fruit: Reduced in size due to leaf loss.
1
3
2
Disease: Septoria
leaf spot caused by Septoria lycopersici.
Disease development conditions? Infection requires a total of 48 hours (can be over several
days) of 100% humidity at 68 to 77˚F. Arises on mature plants with full canopies. Full canopies
prevent drying of the lower leaves by shading and reducing air movement.
References
Hansen, M. A. 2000. Septoria leaf spot of tomato. Virginia Cooperative Extension Plant Disease Fact Sheet 450-711W.
“Septoria leaf spot of tomato.” 2006 Pest Management Fact Sheet, University of Maine Cooperative Extension, Orono,
Maine.
Tomato
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Pest Fact Sheet
Jordan E. Eggers
Plant: Potato
Symptoms
Leaves: Pale green water soaked spots starting at leaf tips turning into brown to purple-black
spots with yellow edges (Image 1). White fuzz present on underside of leaves. Leaves rot quickly
in moist conditions and quickly shrivel in very dry conditions (Image 2). Stems: Infected areas
appear brown or black (Image 3). Tubers: Brown, dry, sunken spots on tuber surface. Tissue
under spots is tan to copper-brown with a granular texture (Image 4).
1
2
3
3
Disease: Late
4
blight caused by Phytophthora infestans.
Disease development conditions? Favorable conditions consist of cool, moist weather with night
temperatures in the 50-60˚F and day temperatures in the around 70˚F. Fogs and heavy dews also
promote infection.
References
Rowe, R. C., S. A. Miller, and R. M. Riedel. 1995. Late blight of potato and tomato. Ohio State University Extension.
Extension Fact Sheet HYG-3102-95.
Potato
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Pest Fact Sheet
Jordan E. Eggers
Plant: Potato
Symptoms
Leaves: Leaves curl up, gradually turn yellow and die early (Images 2 & 4). Stems: Mushy light
brown to inky black lesions on base of stem (Images 2 & 3). Aerial tubers may form on stems.
Tubers: Slightly sunken brown patches on the surface with a reddish-brown discoloration in the
flesh below, developing into a black, slimy rot (Image 1). Spots usually begin at the stem.
1
3
Disease: Black
2
4
leg caused by Erwinia carotovora subsp. atroseptica
Disease development conditions? Disease development is favored by cool (below 50° F), wet
soils at planting followed by high soil temperatures (75˚F) after emergence. Bruising of seed tubers
also favors disease development.
References
Potato (Solanum tuberosum) bacterial soft rot and blackleg. An Online Guide to Plant Disease Control. University of
Oregon Extension Plant http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=882
Rowe R. C., S. A. Miller, and R. M. Riedel. 1995. Blackleg, aerial stem rot, and tuber soft rot of potato. Ohio State
University Extension Fact Sheet HYG-3106-95.
Potato
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Potato
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Pest Fact Sheet
Disease: Blackleg caused by the bacteria Erwinia carotovora subsp. carotovora (ECC) and
Erwinia carotovora subsp. atroseptica (ECA).
Plant: Potato
Symptoms: Contaminated seed pieces rot early in the growing season before emergence. Severe cases result in rotting of
entire seed pieces and sprouts before emergence and poor stand establishment. Infected plants may appear scattered in rows,
skins also may appear in rows. Infected plants that do emerge have stunted, yellow leaves (1) that roll up at edges, wilt, and
may die and a light-brown to inky-black decay of stems extending up from the base of the stem 1-24 inches or more even after
establishment and flowering (2, 3). These plants infected prior to emergence typically die. Mature plants not affected before
emergence can be infected through wounds, leaf scars, and other natural openings in the stem and exhibit the same symptoms
as those infected before emergence. Infections on mature plants is referred to as aerial blackleg (4). Tubers infected with black
leg are soft and watery with a somewhat granular texture and have a foul smell as decay progresses. Black borders often
separate healthy and diseased tissues, the latter of which are cream to tan colored (5).
Disease development conditions: ECC is common an early season problem and affects many fleshy vegetables and survives readily in
soil and water. Aerial black leg is normally caused by ECC spread by water, wind-blown rain, and insects. ECA is more specific to
potatoes and does not survive readily (longer than one year) in soil and water but does overwinter in infested potato plant parts and spreads
in infected seed pieces/tubers, but the bacterium usually remains dormant unless conditions are favorable. Moisture and temperature are
most critical for initiation and development of blackleg. High soil temperatures and tuber damage lead to pre-emergence infections. The
disease is most severe when soils are cool and wet at planting and temperatures are high after emergence. Infections occur anywhere
above 50o F but develop best above 75o F. Elevated moisture and related oxygen depletion lead to infections in seed pieces in soil or stored
tubers.
1
3
4
2
5
References
Rowe, R.C., Miller S.A., Riedel, R.M. 2009. Blackleg, aerial stem rot, and tuber soft rot of potato. Ohio State University Extension Fact
Sheet HYG-3106-95.
Sparks, A., Kennelly, M. 2008. Blackleg of potato. Kansas State University Agricultural Experiment Station and Cooperative Extension
Service Publication EP-149.
John F. Baniecki, Ph.D. Jordan
E. Eggers
Plant: Beans
Symptoms
Wilting of whole plant. Leaves: Leaves turn yellow, dry up, and drop off. Stems: Dry rot of stem
and main tap root near the soil line. Stem tissue brick red in color, may gradually darken and
becoming necrotic (Images 1-4). Pods: Small pods with undersized seeds.
1
2
3
4
Disease: Root
2 and 3).
rot caused by Fusarium solani (Images 1 and 4) or Rhizoctonia solani (Images
Disease development conditions? Hot weather and dry or overly saturated, coarse-textured,
acidic and poorly fertilized soils favor development of Fusarium root rot. Warm (75˚F to 85˚F) and
relatively dry soil conditions favor development of Rhizoctonia root rot.
References
Abawi G. S., D. C. Crosier, and A. C. Cobb. 1985. Root rot of snap beans in New York. New York’s Food and Life
Sciences Bulletin 110.
Dixon, G.R. 1981. “Pathogens of Legume Crops: Bean Crops” in Vegetable Crop Diseases. AVI Publishing Company,
Inc. Westport, Connecticut.
McNab, A. 2007. Beans: root rot diseases. Penn State University Vegetable Disease Identification Website:
http://www.ppath.cas.psu.edu/EXTENSION/VEGDIS/VegDisases/Identification_files/bean_rrot.html
Beans
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Beans
Symptoms
Young plants and sometimes older plants wilt and die Leaves: General wilting. Stems: Disease
begins as a colorless to dark brown wet rot near the soil line (Image 1). The outer tissue of the
stem becomes slimy and can easily slip from the central core. Eventually stems dry out, become
sunken, and turn tan to brown in color (Image 2). At this point the stems feel hollow like a soda
straw. Pods: Pods that contact the soil may develop a soft watery rot. The white fuzz of the
mycelium may be visible. Roots: Watery soft rot of main root and extensive root pruning.
1
Disease: Damping
2
off, hollow stem rot, or root rot caused by Pythium spp.
Disease development conditions? Moderate to high temperatures and excess soil moisture with
poor drainage are ideal for disease. Also, continuous planting of beans in the same field and poor
seed quality (more that 2 years old) may increase risk of disease development.
References
Dixon, G.R. 1981. “Pathogens of legume crops” in Vegetable Crop Diseases. AVI Publishing Company, Inc. Westport,
Connecticut.
McNab, A. 2007. Beans: root rot diseases. Penn State University Vegetable Disease Identification Website:
http://www.ppath.cas.psu.edu/EXTENSION/VEGDIS/VegDisases/Identification_files/bean_rrot.html
Schwartz, H. F. 2006. Root rots of dry beans. Colorado State University Cooperative Extension. Fact Sheet no. 2.938
Beans
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Beans
Symptoms
Leaves: Dark brown to black spots with brick red to purple borders (Image 2). Most commonly
seen on leaf petioles and on lower surfaces of leaves and leaf veins. Stems: sunken oval spots
that are brown to black with purple to brick-red borders extending up and down the stem. Pods:
Initially small, reddish-brown elongated spots form becoming somewhat circular and sunken at the
center (Image 1 & 2). Spots vary in color from tan, brown, reddish brown to black rusty-brown. A
slightly raised border forms around each spot (Image 4). Older spots may be over 1/4 inch in
diameter. During wet weather a mass of pinkish colored spores can be seen on the spots. Young
pods may shrivel and dry if severely infected. Seeds: infected seeds have dark, sunken lesions of
various sizes, which may extend through the seed coat (Image 3). Spots may form on cotyledons
of germinating infected seed.
1
2
3
4
Disease: Anthracnose caused by Colletotrichum lindemuthianum
Disease development conditions?. Planting infected seed, planting in fields with infected
debris, and cool, wet weather increase the risk of disease development.
References
Sikora, E., J. Kemble, and E. Bauske. Common diseases of snap and lima beans. Alabama Cooperative Extension
System. Factsheet ANR-1024.
Beans
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Pest Fact Sheet
Jordan E. Eggers
Beans
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Pest Fact Sheet
Plant: Beans
Symptoms
Leaves: General wilting. Stems: Stems are often the first plant part to become infected and this
occurs usually at the soil surface. Water soaked spots are typical of infection. When dry, the
spots have a white or beige color. White fuzz can also be present on the stem surface. Later on in
infection small, black, seed-like structures form in plant tissue or white fuzz. Infected stems may
have a papery appearance. Stem infections may result in plants falling over. Pods: Water soaked
spots similar to those on the stem. When dry, the spots have a white or beige color. The white
fuzz and small, black, seed-like structures may also be present on pods (Image 1).
1
Disease: Sclerotinia
rot or white mold caused by Sclerotinia sclerotiorum
Disease development conditions? Spores are produced after a period of several weeks at 40°F in
moist soil followed by 59 to 65°F degree temperatures. Moist conditions within the plant canopy favor
infection. Rain, dew, and/or irrigation practices that keep foliage wet for long periods favor white mold
development.
References
Ocamb, C. M. and D.H. Gent. 2007. Bean, snap (Phaseolus vulgaris) -- White mold (Sclerotinia rot). An online guide to
plant disease control. Oregon State University Extension Service. http://plantdisease.ippc.orst.edu/disease.cfm?RecordID=135
Jordan E. Eggers
Plant: Beans
Symptoms
Leaves: Leaves have light green-yellow and dark green mosaic pattern and are curled or cupped
down ward giving them a arched, puckered or blistered appearance (Image 2 & 3). Leaves are
reduced in size. Stems: Excessive number of lateral shoots.
2
1
3
Disease: Bean
Common Mosaic Virus
Disease development conditions? Heavy aphid (Image 1) infestations and planting uncertified
seed may increase risk of virus spread and disease development.
References
Davis, R. M., A. E. Hall, and R. L. Gilbertson. 2001. Dry beans: bean common mosaic. University of California Pest
Management Guidelines, UC IPM Online: http://www.ipm.ucdavis.edu/PMG/r52101611.html.
Beans
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Pest Fact Sheet
Jordan E. Eggers
Beans
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Pest Fact Sheet
Plant: Beans
Symptoms
Leaves: Leaves curl or wrinkle. Leaf surface is bumpy with small light yellow spots (Images 1 &
3). Eventually, most of the leaf will turn yellow (Image 2). Stems: The length of stem between
nodes gets shorter. More lateral shoots are produced. Plants look bushy and stunted. Pods:
Fewer pods are produced.
2
3
1
Disease: Bean
yellow mosaic virus
Disease development conditions? Large aphid populations and planting beans near clover crops
increases the risk of disease development.
References
Davis, R. M., A. E. Hall, and R. L. Gilbertson. 2001. Dry beans: bean yellow mosaic. University of California Pest
Management Guidelines, UC IPM Online: http://www.ipm.ucdavis.edu/PMG/r52101511.html
Dixon, G.R. 1981. “Pathogens of legume crops: Viruses” in Vegetable Crop Diseases. Westport, Connecticut: AVI
Publishing Company, Inc.
Jordan E. Eggers
Corn
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Pest Fact Sheet
Plant: Corn
Symptoms
Leaves, Stalks, Ears, and Tassels: Large galls can develop on any part of the plant at any stage
(Images 1-3 & 5). Most common on the ears (Images 2 & 3). These galls are covered with a
whitish green skin at first. As they age they darken and break open. The inside of the galls is dark
brown or black and has a powdery texture (Images 3 & 5). Yellow or white spots or streaks may
develop on the leaves (Image 4).
2
1
3
4
Disease: Corn
5
smut caused by Ustilago maydis
Disease development conditions? Hot dry weather followed by periodic rain are good conditions
for disease development. Plants are more susceptible before ear formation.
References
Dixon, G.R. 1981. “Pathogens of monocotyledon crops” in Vegetable Crop Diseases. AVI Publishing Company, Inc.
Sherff, A. 1979. Vegetable Crops: Smut of Sweet Corn. Vegetable MD Online. New York State Cooperative Extension,
Cornell University. Fact Sheet 727.20.
Jordan E. Eggers
Corn
Quick Reference
Pest Fact Sheet
Plant: Corn
Symptoms
The whole plant is stunted. Leaves: Pale yellow or brown stripes on leaves (Images 1, 3, & 4).
Leaves may have wavy margins. When cut, leaves exude a yellow slime (Image 2). The leaves
wilt progressively from the base of the plant upwards.
2
3
1
Disease:
4
Bacterial wilt or Stewart's wilt caused by Erwinia stewrtii.
Disease development conditions? The bacteria over winter and are introduced and spread by the
corn flea beetle. Warm winters may lead to higher populations of the beetles and increase spread of
the disease. Infected seed can also introduce the bacteria into fields.
References
Dixon, G.R. 1981. “Pathogens of monocotyledon crops” in Vegetable Crop Diseases. AVI Publishing Company, Inc.
Sherff, A. and T. Woods. 1979. Vegetable crops: Stewart’s disease of corn. Vegetable MD Online. New York State
Cooperative Extension, Cornell University. Fact Sheet 727.10.
Jordan E. Eggers
Corn
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Pest Fact Sheet
Plant: Corn
Symptoms
Plants are stunted and have reduced yields. Leaves: A mosaic mottled pattern of light and darker
green streaks on the all leaves including flag and husk leaves, and is most striking at the whorl
stages (Images 1-3). This may turn into a general yellowing as the growing season progresses
Ears: Ears show poor cob and tip fill (Image 4).
2
1
3
Disease: Maize
4
dwarf mosaic virus
Disease development conditions? High aphid populations and planting non-resistant corn
varieties can lead to quick spread of the disease.
References
Lipps P. E. and D. R. Mills. Maize dwarf mosaic, maize chlorotic dwarf diseases of corn. Ohio State University Extension.
Fact Sheet AC-0024-01.
Zitter, T. A. 1984. Vegetable crops: diseases of sweet corn - Virus diseases. Vegetable MD Online. New York State
Cooperative Extension, Cornell University. Fact Sheet 727.30.
Jordan E. Eggers
Pepper
Quick Reference
Pest Fact Sheet
Plant: Peppers
Symptoms
Leaves: Symptoms begin as water-soaked spots on underside of leaves. These spots turn brown
and become slightly raised and are irregularly shaped. On the upper surface of the leaf the spots
are beige and sunken with a brown border (Images 2 & 4). Affected leaves tend to turn yellow and
drop (Image 1). Fruit: Raised, scab-like spots develop on fruit (Image 3). Fruit may also have
sunscald due to exposure to sun because of dropped leaves.
1
3
Disease: Bacterial
2
4
leaf spot caused by Xanthomonas campestris pv. vesicatoria.
Disease development conditions? The disease if favored by long periods of high relative humidity
(more than 85%) with free moisture on the leaves. Bacteria are spread from plant to plant by
splashing rain and by touching and handling wet plants.
References
McGrath, M. T. and J. Boucher. Managing bacterial leaf spot in pepper. Vegetable MD Online. New York State
Cooperative Extension, Cornell University.
Zitter, T. A. 1985. Bacterial spot of pepper. New York State Cooperative Extension, Cornell University. Fact Sheet
736 10
Jordan E. Eggers
Pepper
Quick Reference
Pest Fact Sheet
Plant: Peppers
Symptoms
Leaves and Stems: Irregularly shaped brown spots with dark brown edges. Fruit: Circular or
angular spots on immature fruit of any size. Often there are multiple spots on one fruit and spots
may grow together to form a larger spot. Pink to orange rings of a dusty substance may be
present on spots (Image 1). There may also be small black specks in older spots.
1
Disease:
Anthracnose fruit rot of pepper caused by Colletotrichum acutatum.
Disease development conditions? Fungus survives in plant debris. Old and infected plant debris
should be removed before replanting. Spores are splashed onto fruit by rain or irrigation. Infection
occurs best at 20–24°C. Fruit must be wet for infection to occur.
References
Cerkauskas, R. 2004. Pepper diseases: anthracnose. AVRDC – The World Vegetable Center Fact Sheet. AVRDC
Publication 04-574.
Ivey, M. L. and S. A. Miller. 2004. Anthracnose fruit rot of pepper. The Ohio State University Extension. Factsheet HYG3307-04.
Jordan E. Eggers
Plant: Cabbage
Cabbage
Quick Reference
Pest Fact Sheet
Symptoms
Leaves: Infections begin as yellow V-shaped spots on the edges of the leaves with the point of the
V in the direction of the veins. Spots enlarge and can go all the way to the stem. As spots enlarge
the tissue rots (Image 1 & 2). Leaf veins turn black (Image 3).
2
1
3
Disease: Black
Rot caused by Xanthomonas campestris pv. campestris
Disease development conditions? Sources of the bacteria include plant debris and infected seed.
The bacteria is spread through splashing water, wind, insects, machinery, and irrigation or drainage
water. Young leaves are the most susceptible to infection.
References
Miller, S. A., F. Sahin, and R. C. Rowe. 1996. Black rot of crucifers. The Ohio State University Extension. Fact sheet
HYG-3125-96
Onion
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Pest Fact Sheet
David McCann, M.S.
Disease: Purple Blotch caused by Alternaria porri
Plant: Onion
Symptoms: Above ground parts and bulbs are infected and show symptoms. Older leaves are usually
affected first. Leaves develop small brown spots that elongate and become sunken and white with a purple
center (1, 2, 3). As spots enlarge they take on a bull’s-eye appearance with alternating light and dark zones.
The borders of well developed spots are reddish-purple with a wide yellow halo. Spots may be up to 4
inches long and become covered with a dark purple-black fungus. Leaves turn yellow, wilt, and die within
several weeks of infection (4, 5). Infected bulbs are spongy and initially yellow but turn wine-red then dark
brown or black over time before becoming dry and papery.
Disease development conditions: The fungus overwinters in diseased plant debris and spreads with wind,
rain, and equipment. Older leaves and plants are more prone to infection. Bulbs are infected at harvest or in
storage through the neck or scale wounds. Frequent rain or persistent moisture is necessary for infection
and disease is most severe at temperatures between 77-81o F. Infection is nearly absent below 55o F.
1
3
5
2
4
References
Delahaut, K., Stevenson, W. 2004. Onion disorders: Purple blotch. University of Wisconsin-Extension, Coopeartive Extension
Publication A3804.
Schwartz, H.F., Gent D.H., Bartolo, M.E. 2007. Onion purple blotch. High Plains IPM Guide. University of Wyoming,
University of Nebraska, Colorado State University and Montana State University Cooperative Extensions.
David McCann, M.S.
Onion
Quick Reference
Pest Fact Sheet
Disease: Downey Mildew caused by Peronospora destructor
Plant: Onion
Symptoms: Irregular oval to cylindrical spots pale-green, brown, or yellow in color appear on infected
leaves or seed stalks. Spots may have alternating layers of yellow and green. Masses of fungi on infected
parts are transparent to gray initially but quickly turn violet in color (1, 2, 3, 4). Leaves are girdled by the
fungus and collapse, resulting in dead tips (5). Dead leaf tissue is colonized by a purple blotch (caused by
the fungus Alternaria porri) which is dark in color and will obscure the downey mildew. Bulbs may
become spongy, grow poorly, and not withstand storage.
Disease development conditions: Downey mildew overwinters in onions left in fields or cull piles.
Infective fungal structures form at night during high humidity and temperatures between 39-77o F before
being spread in the daytime by air currents. Infection occurs with free water and temperatures between 3482o F. Rain is not necessary for infection if heavy dew persists through the night and morning. Infected
plants in fields produce fungal structures in 11-15 day cycles that successively infect lower portions of
leaves below dead upper areas of the same leaves. These repeating cycles results in severe and persistent
epidemics.
3
1
5
2
References
Lorbeer, J.W., Andaloro, J.T. 1984. Cornell University Cooperative Extension Fact Sheet Page 737.20.
4
David McCann, M.S.
Onion
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Pest Fact Sheet
Disease: Botrytis Leaf Blight caused by Botrytis squamosa
Plant: Onion
Symptoms: Spotting, dieback, and blighting of leaves. Leaf spots are whitish and surrounded by greenish-white
halos that appear water-soaked when first formed (1, 2, 3). Spots often are oval and up to ¼ inch long. Centers of
the spots usually become sunken, straw colored, and may develop a characteristic slit that is oriented lengthwise in
the lesion (4). Older leaves are more prone to infection than younger ones. Severely affected fields often take on a
yellowish cast (5). This disease reduces bulb growth and should not be mistaken for Botrytis leaf fleck caused by
Botrytis cinerea (gray mold) which first appears as small superficial flecks; ozone injury appearing as tiny necrotic
flecks lacking water-soaked margins; environmental damage due to hot, dry conditions; pale green to silvery spots
and bruises caused by heavy rain or hail; or herbicide damage related pock marks.
Disease development conditions: The fungus overwinters as a black, compact, hardened mass of fungi that can
survive unfavorable environmental conditions. Infection and spread occurs during extended periods of leaf wetness
resulting from prolonged periods of wet, humid conditions. Optimum temperatures for infection and fungal growth
are from 50-75o F.
2
1
3
5
4
References
Delahaut, K., Stevenson, W. 2004. Onion disorders: Botrytis leaf blight, leaf fleck, and neck rot. University of WisconsinExtension, Coopeartive Extension Publication A3803.
Lorbeer, J.W., Andaloro, J.T. 1983. Cornell University Cooperative Extension Fact Sheet Page 737.10.
David McCann, M.S.
Onion
Quick Reference
Pest Fact Sheet
Disease: Botrytis Neck Rot caused by Botrytis squamosa,
B. allii, and B. cinerea
Plant: Onion
Symptoms: Symptoms usually appear around the neck of the bulb (1, 2) after harvest but infections begin in the
field. Infected areas are softened, sunken, and brown to gray in color (3). These symptoms spread toward the base
of the bulb over time (4). Gray mold may appear on scales in humid environments, but sometimes the mold is only
visible when outer scales are removed (5). A compact, hardened mass of fungi also may appear between scales
which is first white, turning black with age. Entire bulbs may appear mummified.
Disease development conditions: The fungus enters bulbs at the neck when tops have been damaged or removed
before adequate drying. Harvest damage to the bulb also may provide points of entry. The fungus overwinters as a
black, compact, hardened mass of fungi that can survive unfavorable environmental conditions. Infection and
spread occurs during extended periods of leaf wetness resulting from prolonged periods of wet, humid conditions.
Optimum temperatures for infection and fungal growth are from 50-75o F.
1
3
5
2
4
References
Delahaut, K., Stevenson, W. 2004. Onion disorders: Botrytis leaf blight, leaf fleck, and neck rot. University of WisconsinExtension, Coopeartive Extension Publication A3803.
Johnson, D.A. 1986. Plant Diseases: Botrytis neck rot of onion. Washington State University Coopeartive Extension Publication
EB1359.
David McCann, M.S.
Disease: Grey Mold caused by Botrytis cinerea
Plants: asparagus, bean, beet, carrot, celery, chicory, crucifers, cucurbits (1),
eggplant, endive, lettuce (2), onion, pepper, potato, rhubarb, rutabaga, shallot,
tomato (3, 4, 5) and others.
Vegetables
Quick Reference
Pest Fact Sheet
Symptoms: Grey mold affects leaves, stems, crowns, flowers, flower buds, seeds, seedlings, bulbs, and virtually
any plant parts excepting roots. The fungus generally prefers a particular part of any given plant it infects. This
disease is called grey mold because any browned or spotted plant material will develop grey, dusty masses on dead
or dying portions (1, 2, 3, 4, 5). A small black, compact, hardened mass of fungi MIGHT appear on dead parts in
late summer on certain plants (see Fruits: Grey Mold fact sheet).
Disease development conditions: New infections may begin in the spring during WET OR VERY HUMID
weather, leaf surfaces usually must be wet for extended periods of 20 or more hours. The fungus may overwinter as
the small black, compact, hardened mass of fungi described above in symptoms. Optimum temperatures for
infection are generally around 60o F, and for fungal growth around 75o F.
1
3
2
4
References
Cornell University Cooperative Extension. 2009. Botrytis blight, Botrytis cinerea fact sheet. http://plantclinic.cornell.edu/FactSheets/botrytis/botrytis_blight.htm
Davis, R.M., Aegerter, B.J., Laemmlen, F.F., Voss, R.E. 2008. UC IPM Pest Management Guidelines: Onion and Garlic. UC ANR Publication 3453
5
Jordan E. Eggers
Apple
Quick Reference
Pest Fact Sheet
Plant: Apple
Symptoms
Leaves: Small, velvety textured, olive green, spots with unclear edges first develop on the under
side of the leaf (Image 2). On some crabapples the infection may be a reddish color. As the
spots age they become darker and their outlines become more distinct (Image 1). If heavily
infected leaves become distorted and can drop off. Fruit: Spots on fruit look similar to those on
the leaves but with a more distinct edge. As the spots age they darken and become black and
with a roughened scabby surface (Images 3 & 4). Heavily scabbed fruit may become deformed
and drop before reaching good size.
1
3
Disease: Apple
2
4
scab caused by Venturia inaequalis.
Disease development conditions? Cool (between 55° and 75°F), wet weather during the early
part of the growing season are ideal conditions for disease development. Leaves or fruit must
remain wet continuously for a minimum of 9 hours for infection to occur.
References
Ellis, M. A., J. Chatfield and E. Draper. 1994. Scab of apple and crabapple. The Ohio State University Extension. Fact
Sheet HYG-3003-1994.
Ohlendorf, B. and M. L. Flint. 2001. Apple scab. IPM Education and Publications, UC Statewide IPM Project, University of
California. Publication 7413.
Jordan E. Eggers
Apple
Quick Reference
Pest Fact Sheet
Plant: Apple
Symptoms
Leaves: Pale yellow spots up to ¼ inch in diameter appear on the upper surface during May or
June. Spots turn orange with time, and often have a reddish border (Images 1 & 3). Very small
black spots form within the orange spot and produce an orange fluid (Image 4). Yellow spots
eventually form on underside of leaf. These spots thicken during the summer. Fruit: Yelloworange spots appear at or near the bottom end of the apple. These spots usually occur on
immature fruit and are much larger than the spots on leaves (up to ¾ inch in diameter). The light
green color of the young fruit becomes a darker green around the infected area. The small tubelike structures may form on the fruit spots (Image 2). Infected fruits are often stunted and
misshapen, and may drop early.
1
2
3
Disease: Cedar-Apple
4
rust caused by Gymnosporangium juniperi-virginianae .
Disease development conditions? Cool temperatures (50 to 70˚F) and periods of extended moist
conditions on leaves and fruit are ideal for disease development. The presence of cedar trees near
apple trees increases risk of infection.
References
Ellis, M. A. 1995. Rusts of apple. The Ohio State University Extension. Fact Sheet HYG-3024-95.
Yoder, K. S. and A. R. Biggs. Cedar-Apple Rust, Gymnosporangium juniperi-virginianae. Kearneysville Tree Fruit
Research and Education Center, West Virginia University.
http://www caf wvu edu/kearneysville/disease descriptions/omcar html
Jordan E. Eggers
Plant: Apple
Symptoms
Blossoms: Infected blossoms wilt, die and turn brown usually one to two weeks after bloom. A
liquid ooze is sometimes present on wilted blossoms. Branches: The tips of infected young
shoots wilt and form a “shepherd’s crook” (Images 1 & 2). Cankers can be found on larger
branches and the trunk of the tree and appear as sunken, discolored areas of bark. These sunken
areas may or may not have cracks around the edge. A thick yellow ooze maybe coming from the
cracks. Leaves: The first symptoms are dark streaks in the middle veins of leaves. The leaves
then wilt and turn brown (Image 3). Wilted leaves remain firmly attached throughout the season.
Fruit: Fewer fruit are produced due to blossom death.
2
3
1
Disease: Apple
.
fire blight
caused by Erwinia amylovora.
Disease development conditions? Blossoms are the primary infection sites. Any twigs or
branches
References
Steiner, P.W., T. van der Zwet, and A. R. Biggs. Fire Blight, Erwinia amylovora. West Virginia University, Kearneysville
Tree Fruit Research and Education Center.
Apple
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Plant: Apple and crabapple (Malus spp.)
Apple
Quick Reference
Pest Fact Sheet
Symptoms
Within two weeks of bloom the first symptoms appear on blossoms that darken, wilt, shrivel and die (1)
.Young shoots wilt and curl at tips forming a shepherd's crook (2). Older shoots infected after forming
about 20 leaves do not form shepherd’s crooks. As infection spreads leaves darken at mid-veins then
turn completely brown as if scorched by fire but remain firmly attached all season (2). Cankers form as
small red to purple areas on twigs and branches (3)or as dark sunken, cracked areas on trunks and
large limbs (4). Under favorable conditions honey-like drops may appear on recently infected plant parts
(5).
2
1
3
4
5
Disease: Fire
Blight caused by Erwinia amylovora
Disease development conditions? The bacterium overwinters in infected tissues, resuming
activity in spring. Dispersal is facilitated by wind, rain, insects, birds, and humans. Symptoms
appear 1-3 weeks after infection depending on temperature and humidity. Warm humid (>60%)
weather favors epidemics. Bacterial growth occurs at temperatures of 59-90oF and is optimal at
81-84oF.
References
Sinclair, W.A, Lyon, H.H. 2005. Diseases of Trees and Shrubs. Cornell University Press, Ithaca, NY.
Steiner, P.W., van der Zwet, T., Biggs, A.R. 2008. Fire Blight, Erwinia amylovora. West Virginia University Kearneysville Tree
Fruit Research and Education Center Fact Sheet.
David McCann, M.S.
Apple
Quick Reference
Pest Fact Sheet
Apple (Malus species)
Symptoms
Leaves: Purple specks appear upper leaf surfaces early in spring, enlarging to circular, perhaps lobed,
spots up to ¼ inch. Older spots have purple margins with brown-tan centers and concentric rings, small
black dots may appear in spot centers (1). Spots look like frog-eyes, hence the term “frog-eye” leaf spot.
Stems: Cankers form in bark wounds, appearing as small reddish-brown sunken areas. Killed bark turns
tan then dark, black dots bursting through roughen the bark (2). Cankers may superficially roughen bark
(3), or kill bark tissues and cause dieback (4). Fruit: Infection appears near the stem as red spots that
turn purple with a red ring. Concentric bands form as infection spreads (5), small black dots may appear,
infected areas turn black on mature fruit, shriveled-up fruit (mummies) may remain on the tree.
1
2
3
4
6
5
Disease: Black
rot (“frog-eye” leaf spot)caused by Botryosphaeria obtusa
Disease development conditions? The fungus overwinters in cankers, bark, and mummies.
Infections occur in the spring during wet weather with moderate temperatures (68-82oF) for 12-24
hours. Relatively long wetting periods are required for fruit infection or infection at relatively low
temperatures
References
Travis, J.W., Rytter, J.L., Biggs, A.R. 2008. Black Rot, Botryosphaeria obtusa West Virginia University Kearneysville Tree Fruit
Research and Education Center Fact Sheet.
David McCann, M.S.
Plant: Peach (Prunus persica)
Peach
Quick Reference
Pest Fact Sheet
Symptoms
Symptoms first appear in spring as blossoms become brown and collapse, adhere to the twig in a sticky
mass, then are covered by a tan to grey powder (1). Later twigs develop brown to black gummy sunken
areas that may girdle the twig and cause dieback (2). Ripe or ripening fruit develop rapidly expanding
brown areas of soft, dry rot (3). Some fruit may shrivel into mummies covered by grey to black powder
(4), they may remain on the tree or drop to the ground and produce cup-like structures (5).
1
2
3
4
5
Disease: Brown
Rot caused by Monilinia fructicola and M. taxa
Disease development conditions? The fungus overwinters in plant parts except during
extreme cold and is dispersed by wind, rain, and insects. Free moisture and moderate
temperatures between 59-77oF are most ideal for infection and disease development.
References
Biggs, A.R., Hickley, K.D., Yoder, S. 2008. Brown Rot, Monilinia fructicola West Virginia University Kearneysville Tree Fruit
Research and Education Center Fact Sheet.
David McCann, M.S.
Peach
Quick Reference
Pest Fact Sheet
Plant: Peach (Prunus persica)
Symptoms
Leaves: Earliest symptoms appear on leaves as angular water-soaked spots typically along tips,
edges, or mid-veins. Spots become purple as they enlarge and tissues die, then they will drop
out of leaves leaving a hole. Leaves may turn yellow and drop from the tree. Fruit: Small, round
brown spots on surface that pit and crack over time. Twigs: Purple water-soaked spots that
become sunken over time appear from spring through fall.
1
2
3
4
Disease: Bacterial
Spot/Shot Hole caused by Xanthomonas campestris pv. pruni
Disease development conditions? The bacterium overwinters in twigs and buds and is
dispersed by water and pruning tools. Frequent wet periods of 18+ hours during the growing
season promote epidemics. Symptom development occurs rapidly at temperatures around 860F.
References
Keil, H.L. 2005. Bugwood.org
Springer, J.K. van der Zwet, T., Biggs, A.R. 2006. Bacterial Spot, Xanthomonas pruni. West Virginia University Kearneysville
Tree Fruit Research and Education Center Fact Sheet.
David McCann, M.S.
Plant: Cherry, Plum, Prune (Prunus spp.)
Cherry
Quick Reference
Pest Fact Sheet
Symptoms
Knots first appear in autumn from spring infections as swellings on new twigs. Sharp bends in
twigs and splitting bark may appear about swellings. Splitting exposes olive-green fungal growth
(1) that will darken during the growing season, turning to hard black knots in winter (2,3). Fungal
structures are produced in cavities in the knot. Knots are perennial with enlargement being
interrupted by winter. Cankerous growths with fungal structures may develop on stems (4,5).
2
1
4
5
3
Disease: Black
knot of cherry caused by Apiosporina morbosa
Disease development conditions? The fungus overwinters in knots and cankerous growths
and is spread by spring rain. Wet periods of at least 6 hours and temperatures from 70-75oF are
optimum for infection, which begin in wounds and mostly in young green shoots. One–two years
are needed for new infections to produce the next generation of the fungus.
References
Hilton, B.H. Jr., . 2003. This Week at Hilton Pond. www.hiltonpond .org.
Firethorn
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Plant: Firethorn (Pyracantha species)
Symptoms
Dark brown to black crusty areas (scabs) appear on fruit in summer and are visible through fall
and winter. Infected fruit may drop during severe infections. Velvety soot-like scabs may appear
on leaves. Spotting, yellowing, browning and premature drop also affect leaves. New twigs may
have black lesions that may girdle the twig and cause dieback.
2
1
3
Disease: Pyracantha scab caused by Venturia inequalis f.sp. pyracanthae (Spilocaea
pyracanthae)
Disease development conditions? The fungus overwinters in plant parts. Disease begins in
spring and is spread by splashing water. Plants are infected during heavy dews and prolonged
rainfall.
References
Hartman, J. 2005. Pyracantha Scab. University of Kentucky Extension Service Plant Pathology Fact Sheet PPFS-OR-W09
Unknown Author. 2000. Firethorn (Pyracantha) Scab. University of Illinois Extension Service IPM RPD No. 638.
Jordan E. Eggers
Plant: Roses
Symptoms
Leaves: Black spots with fringed borders up to ½” in diameter primarily on the upper leaf surface
(Images 1 & 3). Leaves begin turning yellow around spots. Eventually entire leaves may turn
yellow and drop (Image 2). Canes: Spots on canes are first purple in color, turning black over
time.
2
1
Disease:
3
Black spot
caused by Diplocarpon rosae.
Disease development conditions? The spores of the fungus must be wet for at least 7 hours
before they can germinate. So ideal conditions for spore germination are wet foliage and
temperatures near 65˚F. The disease develops most rapidly at about 75˚F.
References
Black Spot of Rose. The University of Maine Cooperative Extension. Pest Management Lab Fact Sheet.
http://pmo.umext.maine.edu/factsht/Spotrose.htm
Flowers
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Rose
Quick Reference
Pest Fact Sheet
Disease: Rose Black Spot caused by Diplocarpon rosae
Plant: Rose
Symptoms: Small, round, black spots 1/16-1/2 inch in diameter with a fringed border appear upper leaf surfaces (1,
2). The area surrounding spots becomes yellow, whole leaves may turn yellow (2, 3) and drop off prematurely.
Spots similar to those on leaves may appear on petioles and fruit, and raised reddish-purple spots may form on
canes (4). Untreated infections may cause cane dieback the following spring.
Disease development conditions: The fungus overwinters in infected leaves and canes and spreads to young,
unfolding leaves in spring by splashing water. Infection occurs only when water stands on leaves for seven hours
or more. High humidity and rainfall or persistent moisture favor disease development and the fungus tolerates a
wide range of temperatures.
2
1
3
4
References
Hansen, M.A. 2009. Rose black spot. Virginia Cooperative Extension, Virginia Tech, Virginia State University.
Heimann, M.F., Worf, G.L. Rose disorder: blackspot. University of Wisconsin-Extension, Coopeartive Extension Publication
A2531.
David McCann, M.S.
Rose
Quick Reference
Pest Fact Sheet
Disease: Powdery Mildew caused by Sphaerotheca pannosa on
rose; other powdery mildews specifically attack certain ornamentals.
Plant: Rose
Symptoms: White to gray powdery, flour-like growth on leaves (1, 2), buds (3), canes (4), or flowers along with
perhaps tiny, white to black dots. Leaves may die and drop off plant prematurely. Leaves may turn yellow, reddish,
or purple and curl or shrivel; other distorted or discolored plant parts may be visible.
Disease development conditions: Warm, dry days followed by cool, moist nights promotes infection. Powdery
mildews can reproduce in 4-6 days at temperatures of 59-82o F. They may survive through winter and very hot
summers. Growth of powdery mildews is best in in humid air.
1
2
4
3
References
Nameth, S., Chatfield, J. 1996. Controlling rose diseases. Ohio State University Extension HYG-3063-96
Jordan E. Eggers
Flowers
Quick Reference
Pest Fact Sheet
Plant: Crown Chrysanthemum, Pot Mums, Pyrethrum Chrysanthemum, Spray Mums,
Marguerite Daisy, Garden Mums, Ox-Eye Daisy, Nippon Daisy, Shasta Daisy, High Daisy, Corn
Marigold, Chrysanthemum pacificum
Symptoms
Leaves: Small white to yellow dimpled spots appear on the upper surface of leaves (Image 1 &
3). These spots turn brown with age. Raised granular-looking bumps (pustules) appear on the
lower surface of leaves. These bumps are first pink or buff colored tuning a waxy white with age
(Images 1, 2, & 4). Severely infected leaves dry up an hang along the stem. Although the
pustules are most frequently found on leaves, they may also develop on stems, bracts, and
flowers.
1
3
Disease: Chrysanthemum
2
4
white rust caused by Puccinia horiana.
Disease development conditions? This pathogen has not yet been found in West Virginia.
Efforts are being made to quarantine this pathogen and prevent its spread. If you suspect that you
have infected flowers, contact your local extension agent immediately.
References
McDonald, L. 2001. Chrysanthemum white rust. British Colombia Ministry of Agriculture, Food, and Fisheries Floriculture
Factsheet. Abbotsford, B.C.
Chrysanthemum White Rust Pest Alert. New York Cooperative Agriculture Pest Survey. New York Department of
Agriculture and Markets & USDA-APHIS-PPQ, Albany, NY.
http://ceris.purdue.edu/napis/pests/cwr/CWR%20Pest%20Alert.pdf
David McCann, M.S.
Zinnia
Quick Reference
Pest Fact Sheet
Disease: Bacterial Leaf Spot caused by Xanthomonas campestris
sub. sp. zinniae
Plant: Zinnia
Symptoms: The bacterium, Xanthomonas campestris sb. sp. zinniae, causes minute, translucent, diffuse spots with
a broad yellow border to appear on leaves. Spots may enlarge to about ¼ inch, become angular or roughly circular
with a reddish center (1,2). Spots may converge and form irregular dead areas up to about ½ inch in size (2, 3).
Small brown spots may appear on flowers (4) that may become disfigured or decay.
Disease development conditions: Warm, wet or humid conditions favor disease development. Overhead
sprinkling, excess shade, and overcrowding also facilitate disease.
1
3
2
4
References
University of Illinois. 1987. Common leaf diseases of zinnia. University of Illinois Extension RPD No. 655.
David McCann, M.S.
Zinnia
Quick Reference
Pest Fact Sheet
Disease: Alternaria Leaf Spot caused by Alternaria zinniae
Plant: Zinnia
Symptoms: Small, reddish brown spots with white to gray centers appear on upper leaf surface. As spots enlarge up
to nearly ½ inch they become irregular in shape and dark reddish brown or purple. Holes may appear as spot centers
fall out. Leaves may turn brown and dry and dead areas might crack and tear. Spots like those on leaves may appear
on petioles and stems, possibly girdling the stem and causing wilt or dieback above that point. Dark brown to black
wounds with sunken centers are common near the soil line and roots turn dark gray, causing entire plants to wilt and
die. Minute brown spots with gray centers may appear on flower petals and enlarge to affect the entire petal and
blight flowers.
Disease development conditions: The fungus, Alternaria zinniae, overwinters in on seed and in soil. Warm, wet or
humid conditions favor disease development. Overhead sprinkling, excess shade, and overcrowding also facilitate
disease.
1
2
References
University of Illinois. 1987. Common leaf diseases of zinnia. University of Illinois Extension RPD No. 655.
David McCann, M.S.
Phlox
Quick Reference
Pest Fact Sheet
Disease: Septoria Leaf Spot caused by Septoria spp.
Plant: Phlox
Symptoms: Small, round, ½ inch, dark brown to black spots with pale centers appear on either leaf surface (1, 2).
Black or brown specks appear within spot centers and may ooze a slimy whitish substance (3). Infected leaves turn
yellow, dry up, and die as spot converge (4).
Disease development conditions: Septoria fungi overwinter in infected leaves and tolerate a wide range of
temperatures. Persistent moisture and standing water favor infection and disease development.
2
1
3
4
References
Schubert, T.S., McRitchie, J.J. 1985. Septoria leaf spot of phlox. Florida Department of Agriculture and Consumer Sciences.
Plant Pathology Circular No. 268.
Smith, S., Cartwright, R. 2007. Plant Health Clinic News. Arkansas Cooperative Extension.
David McCann, M.S.
Phlox
Quick Reference
Pest Fact Sheet
Disease: Powdery Mildew caused by Erysiphe cichoracearum
Plant: Phlox
Symptoms: White to gray powdery, flour-like growth on leaves (1, 2), along with perhaps tiny, yellow to black dots
(3). Disease begins on lower leaves and moves up the plant; by late summer lower leaves are wilted and dead and
upper leaves are covered by the fungus. Overall plant vigor is poor.
Disease development conditions: Powdery mildews overwinter in diseased plant material. Short wet periods favor,
but long wet periods inhibit, infection and disease development. Powdery mildews can reproduce in 4-6 days at
temperatures of 59-82o F. They may survive through winter and very hot summers. Growth of powdery mildews is
best in moderate summer temperatures and humid air.
2
1
3
References
Flynn, P. 2003. Powdery mildew on phlox. Iowa State University Extension Horticulture and Home Pest News.
Hartman, J. 2007. Phlox powdery mildew. University of Kentucky Extension Plant Pathology Fact Sheet PPFS-OR-H-08
David McCann, M.S.
Iris
Quick Reference
Pest Fact Sheet
Disease: Iris Leaf Spot caused by Heterosporium iridis
Plant: Iris
Symptoms: Both sides of leaves and upper portions especially usually display symptoms that also may appear on
stems and flower buds. Small green to yellow water soaked spots turn red-brown and dry in the center with yellow
margins (1). As spots enlarge they become oval shaped. Older spots have red-brown margins with gray centers (2).
When moist spots may have dark green-brown tufts of fungal growth in the center (3). Spots can merge and form
irregular dead areas, leaves may turn yellow and dieback from tips (4). Bulbs are not infected but dieback of leaves
may kill the entire plant.
Disease development conditions: The fungus overwinters in diseased leaves and flower stems. Spring rain spreads
the fungus for new infections early in the season. The disease spreads further as rain splashes the fungus from these
new infections to other plants.
2
1
4
3
References
Hansen, M.A. 2009. Iris leaf spot. Virginia Cooperative Extension, Virginia Tech, Virginia State University.
Ruhl, G. 2009. Iris leaf spot. Plant and Pest Digital Library Project, Purdue University.
University of Illinois. 1982. Iris leaf spot. University of Illinois Extension RPD No. 628.
Jordan E. Eggers
Plant: Oak, Elm, Sycamore, Willow, Fir, Maple,
Hemlock, Cottonwood, Poplar, Mulberry, and other tree species.
Symptoms
Trunk: A watery, foul smelling ooze (slime flux) coming from branch scars, old wounds, cracks, or
holes in the bark. The slime flux is made up of bacteria, sap, water and yeasts. This ooze runs
down the trunk, causing dark streaks that become gray or white when dry (Images 1 & 2). The
wood under the bark is often discolored. Branches: Decline or die back may occur.
1
Disease: Wet
2
wood caused by Enterobacter cloacae, other bacteria, yeasts, and other fungi.
Disease development conditions? Improper pruning of branches and wounding can lead to wet
wood. Pruning trees with tools used to prune or cut down other trees with wet wood can lead to
introduction of the bacteria into new trees.
References
Gillman, D. H. 2005. Wet wood and slime flux. University of Massachusetts Extension.
Sinclair, W. A. and H. H. Lyon. 2005. Diseases of trees and shrubs. Ithaca: Cornell University Press.
Trees
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Trees
Quick Reference
Pest Fact Sheet
Disease: Armillaria Root Disease (shoestring root rot) caused by
Armillaria spp.
Host Plant: Various hardwood and conifer species.
Symptoms and Signs: Symptoms appear as swollen resinous butts, excessive cone crops, resin crusted roots and
needle loss on conifers, which die from the bottom up and inside out (1). On hardwoods sunken areas of loosened
bark may appear but are usually inconspicuous. General symptoms include discolored leaves, thin crown, reduced
leaf size, and general low vigor. The fungus can survive many years on woody debris and stumps. Black shoestringlike structures (2), fan-like fungal structures (3) may be found under bark of infected stumps and butts.
“Shoestrings” also may be found on root surfaces. Mushrooms grow around infected bases and on woody debris in
the fall (4). Armillaria spp. invade sapwood and cause a white, stringy, spongy rot.
Disease development conditions: The fungus can survive many years on woody debris and stumps. Shoestrings
infect roots directly. Root grafts spread the fungus to new hosts. Mushrooms release fungal structures that can infect
fresh wounds. Infection can occur year-round. Most North American Armillaria spp. are inhibited by soil
temperatures above 790F.
1
2
3
4
References
Williams, R.E., Shaw, G.C. III, Wargo, P.M., Sites, W.H. 1989. Forest Insect Disease Leaflet 78: Armillaria Root Disease. USDA Forest
Service
David McCann, M.S.
Trees
Quick Reference
Pest Fact Sheet
Disease: Heart Rot caused by Oxyporus populinus
Hosts: Maple, ash, aspen, basswood, beech, sycamore, buckeye, dogwood, elm, willow, hickory
Distribution: Throughout eastern North America from Georgia to southern Canada, west to Arkansas; also
Pacific Northwest
Indicators/Symptoms: Shelf-like fungus present year after year, lower surface white to cream, upper
surface white, often moss-covered with age (1-3). The fungus develops in cracks, basal wounds and
cankers caused by other fungi (3). White, spongy rot of heartwood and sapwood. Damage limited to a
meter above and below the fungus. The fungus is a cavity former and birds are attracted to it because it
creates nest sites.
1
2
3
References
O'Brien, J. 2007. USDA Forest Service, Bugwood.org (1,3)
Minnesota Department of Natural Resources Archive. 2007. Minnesota Department of Natural Resources, Bugwood.org (2)
Sinclair, W.A, Lyon, H.H. 2005. Diseases of Trees and Shrubs. Cornell University Press, Ithaca, NY
David McCann, M.S.
Disease: Root Rot caused by Heterobasidion annosum
Trees
Quick Reference
Pest Fact Sheet
Hosts: Conifers
Distribution: Throughout the eastern United States (most common in the South) and the Pacific Northwest.
Indicators/Symptoms: Shelf-like fungus survives year after year, lower surface creamy white, upper surface lightgray to reddish-brown (1). Fungal shelves develop near the soil line on roots or root collars of living trees, stumps,
slash, and dead roots (2,3). The fungus rots heartwood and sapwood. Irregular pinkish to violet stain occurs in
developing infections; resinous patches may appear on roots or butts; fungal “fans” may appear under bark (4).
Infected trees exhibit no symptoms or a bottom-up, inside-out death.
Disease development: Infection occurs via root grafts and fungal structures infecting fresh stumps or wounds.
Stressed trees are prone to infection. Infection is most severe in plantations and sites with sandy soils.
1
4
2
3
References
O'Brien, J. 2007. USDA Forest Service, Bugwood.org (1,2)
Mistretta, P.A. 2007. USDA Forest Service, Bugwood.org (3)
USDA Forest Service - Region 8 Archive. 2007. USDA Forest Service, Bugwood.org (4)
David McCann, M.S.
Trees
Quick Reference
Pest Fact Sheet
Pathogen: tinder fungus, Fomes fomentarius
Hosts: Many hardwoods, especially beech, birch, maple, willow, poplar, cherry
Distribution: Throughout temperate hardwood regions of North America and Eurasia
Indicators/Symptoms: Woody hoof-shaped fungus survives year after year, lower surface off-white to tan
with relatively large pores, upper surface variable—light gray to dark gray (perhaps with black lines), or
solid black (1-4). This fungus rots heartwood and sometimes sapwood.
Disease development: Spread of this fungus is primarily in spring but may occur anytime in the growing
season. This fungus attacks living or dead hosts.
1
2
3
4
References
Frank, N. 2009. University of West Hungary, Bugwood.org (2)
Kunca,, A. 2009. National Forest Centre - Slovakia, Bugwood.org (1,3)
Wojciech, G. 2004. Polish Forest Research Institute, Bugwood.org (4)
Jordan E. Eggers
Plant: Flowering Dogwood
Symptoms
Leaves: Infections begin as small spots with tan centers and reddish to purple margins on the
leaves (Images 1 & 4). These spots often begin showing up in the lower leaves first. During wet
cool periods, these spots can grow together to form large irregular spots or kill entire leaves.
Branches: Infections can progress from the leaves into the twigs (Image 3), down branches, and
into the main stem of the tree causing brown sunken areas (cankers). Cankers are chocolate
brown in color as opposed to the tan color of the healthy wood (Image 2). Cankers can girdle
branches and whole trees causing branch dieback and death of the entire tree. New shoots may
arise in large numbers on the lower trunks of trees that have extensive cankering or branch loss.
Flowers: Small spots with tan centers and reddish purple margins may be present on flower
bracts and petals (Image 5).
2
1
3
4
Disease: Dogwood
5
anthracnose caused by Discula distructiva.
Disease development conditions? Wet, cool weather increases the risk of disease development.
References
Doubrava, N.and J. McLeod Scott, J. H. Blake, C. S. Gorsuch, and J. Williamson. 2007. Dogwood Diseases & Insect
Pests. Clemson Extension Home and Garden Information Center. http://hgic.clemson.edu.
Gillman, D. H. 2005. Dogwood anthracnose. UMass Extension Landscape, Nursery & Urban Forestry Program.
Dogwood
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Maple
Symptoms
Leaves: Light green to yellow green spots develop on the top of leaves in late spring or early
summer. During mid to late summer, black spots begin forming on the top of leaves (Images 1-4).
These spots have the appearance of tar that has been dripped on the leaves. The spots can be
made up of many pin point spots (Images 2 & 4) or a single large spot that often has a rippled
surface (Images 1 & 3). The underside of the leaf directly below the tar spot turns brown and is
cupped downward. Heavily infected leaves may drop early.
1
3
Disease: Tar
2
4
spots caused by Rhytisma species.
Disease development conditions? Infected leaves that are not cleaned up and destroyed may
lead to more leaf spots in subsequent years. Trees in over all poor health are more susceptible.
References
Maple
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Maple
Symptoms
Leaves: Disease starts as small (usually less than 2 inches) irregularly round, brown spots. Spots
later have a tan center with a dark border that is often red or purple in color (Images 1, 3, & 4).
Spots may grow together resulting in large irregular dead areas on leaves. Small pinpoint black
spots arranged in a circle may develop in the tan area of the larger spot. The centers of the large
spots may fall out leaving holes in the leaves (Image 2).
1
2
3
Disease: Phyllosticta
4
leaf spot
caused by Phyllosticta minima.
lead to more leaf spots in subsequent years. Trees in over all poor health are more susceptible.
References
Maple
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Maple
Symptoms
Leaves: Irregular purple or brown spots form along or near leaf veins (Image 1). Spots enlarge
and often grow together forming large dead areas on leaves (Images 2 & 3). These dead areas
can extend all the way to the edge of leaves. Leaves also may become twisted, crinkled, or
otherwise deformed. Early leaf drop is common. Branches: Young shoots may also become
infected and killed.
1
2
3
Disease: Maple
anthracnose
caused by Discula species.
lead to more leaf spots in subsequent years. Ideal conditions for infection are cool temperatures
and wet weather.
References
Tisserat, N. 1995. Anthracnose diseases of shade trees. Kansas State University. http://www.oznet.ksu.edu.
Maple
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Plant: Maple
Symptoms
Leaves: Leaves on one side of the tree wilt and curl, dry up, turn red or yellow between the veins
or have a scorched appearance (Images 1 & 4). In long lasting infections leaves may be small
and sparse in some areas of the canopy. Early leaf fall also may occur. Branches: Stunted
growth and dieback. Green or black discoloration is visible when outer bark is removed or
branches are cut (Images 2 & 3). Death of entire trees is possible.
2
1
3
Disease: Verticillium
4
wilt caused by Verticillium albo-atrum and V. dahliae.
Disease development conditions? Development of Verticillium wilt is favored by factors that
stress roots, including wounding and droughty conditions.
References
Chatfield, J., S. Nameth and N. Taylor. 1996. Verticillium wilt of landscape trees and shrubs. The Ohio State University
Extension. Fact Sheet HYG-3053-96.
Maple
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
Elm
Quick Reference
Pest Fact Sheet
Plant: Elm
Symptoms
Leaves: The first symptom is leaf wilting. Leaves wilt and then turn yellow and brown (Images 1
& 3). Leaf wilt can be first observed in either the upper or lower crown depending where the
infection began. Branches: Brown to black streaks may be visible on branches when the outer
bark is removed. Growth can sometime cover the rings, leaving staining in the inner wood (Image
2). Trunk: Brown to black streaks may be visible in outer sapwood when bark is removed from
trees that are completely wilted (Image 4).
1
2
3
4
Disease: Dutch
elm disease caused by Ophiostoma ulmi.
Disease development conditions? The fungus is spread through the roots, so any oaks near other
oaks that are wilting my contract the disease. The fungus spread long distances by elm bark
beetles. Destroy or completely remove elms killed by DED, because the beetles live and reproduce
in the logs where they can pick up the fungus.
References
Haugan, L. 1998. How to manage and identify Dutch elm disease. United States Department of Agriculture Forest
Service. Fact Sheet NA-PR-07-98.
Jordan E. Eggers
Oak
Quick Reference
Pest Fact Sheet
Plant: Oak
Symptoms
Leaves: Leaves at or near the top of a tree turn dull green, bronze or tan, beginning along the tips
and edges (Images 1 & 4). There is often a abrupt line between the dead part of the leaf and the
part that is still green. Leaves wilt from the top of the tree down. Branches: Brown to black
streaks may be visible on branches when the outer bark is removed (Images 5). Trunk: Brown to
black streaks may be visible in outer sapwood when bark is removed from trees that are
completely wilted. The summer after a tree has died from wilt, the fungus will form small fungal
mats under the bark. The mats are first gray or white in color (Image 2) and darken with age
(Image 3). The first evidence of these mats are cracks in the outer bark. The mats can be viewed
by pulling off the bark around the cracks. There may also be a sweet or fermented smell that
accompanies the mats.
1
2
4
Disease: Oak
3
5
wilt caused by Ceratocystis fagacearum.
Disease development conditions? The fungus is spread through the roots, so any oaks near other
oaks that are wilting my contract the disease. Red oaks are more strongly affected by the fungus
than white oaks. The fungus is also spread by small sap feeding beetles. Avoid pruning oaks from
early June through August.
References
Bonello, P. 2001. Oak wilt. Thee Ohio State University Extension. Fact Sheet HYG-3306-01.
Jordan E. Eggers
Oak
Quick Reference
Pest Fact Sheet
Plant: Oak
Symptoms
Leaves: Irregularly shaped, random brown spots form on infected young leaves. These spots are
often found along leaf veins and there is a distinct difference between the appearance of health
and infected leaf tissue (Images 1 & 2). Heavily infected leaves may be curled, distorted or have
deformed edges (Images 3 & 4). Older leaves develop small brown spots during wet weather that
may grow together. Heaviest leaf infections occur on the lower branches. Branches: Branch
dieback may occur in heavy infections.
1
3
Disease: Oak
2
4
anthracnose caused by Discula quercinia.
Disease development conditions? Infections occur more frequently on white oaks. Young leaves
are especially susceptible. Infection occurs during long periods of cool wet weather.
References
Gilman, D. 1999. Yard and garden breif: oak anthracnose. University of Minnesota Extension Service.
Jordan E. Eggers
Plant: Oak
Symptoms
Leaves: Light green to yellowish blister-like, roughly circular bulges on upper leaf surfaces.
Viewed from the lower leaf surface, these deformities appear as depressions in the leaf. Blisters
tend to brown as the season progresses.
1
2
3
4
Disease: Oak
leaf blister caused by Taphrina caerulescens.
Disease development conditions? Spores infect leaves as they open. Mild, moist spring
conditions favor infections. This is the only infection that occurs each season. Leaves become
resistant to infection as they mature.
References
Nameth, S., N. Taylor, and J. Chatfeild. 1996. Leaf diseases on ornamental trees and shrubs. The Ohio State University
Extension Service. Factsheet HYG-3044-96
Oak
Quick Reference
Pest Fact Sheet
Juniper
Quick Reference
Pest Fact Sheet
David McCann, M.S.
Plant: Juniper species, red cedar
Symptoms
Needles/Twigs: Symptoms are similar to those of Phomopsis twig blight. However, healthy,
undamaged needles cannot be infected and symptoms appear early in the spring before new
growth begins, whereas Phomopsis symptoms appear on healthy needles throughout the
growing season. If symptoms appear on twigs that were healthy the previous fall, then Kabatina
is likely responsible. Also, Kabatina does not produce a sticky substance. (see Phomopsis twig
blight fact sheet)
2
1
Disease: Juniper
twig blight caused by Kabatina juniperi
Disease development conditions? First symptoms appear early in spring. Infection occurs on
wet surfaces at 68-75oF. Long wet periods promote disease. Temperatures of 46-54oF delay
infection, severe symptoms are produced at 79-90oF.
References
Hartman, J., Eshenaur, B. 2005. Twig Blights of Juniper. University of Kentucky Extension Service Plant Pathology Fact Sheet
PPFS-OR-W11
David McCann, M.S.
Juniper
Quick Reference
Pest Fact Sheet
Plant: Juniper species, red cedar
Symptoms
Needles/Twigs: Mature needles are resistant. Disease will first appear on immature needles as
small yellow spots. Diseased shoots fade to light green then reddish brown. Gray bands mark
points of infection at bases of killed shoots which remain on plant for several months. Numerous
gray to black dots embedded in tissue appear in the gray bands 3-4 weeks after infection. A
yellowish, sticky substance covering dots may be visible during wet weather.
1
2
1
Disease: Juniper
3
4
twig blight caused by Phomopsis juniperivora.
Disease development conditions? First symptoms appear during warm wet weather. Infection
occurs on wet surfaces at 68-75oF. Long wet periods promote disease. Temperatures of 46-54oF
delay infection, severe symptoms are produced at 79-90oF.
References
David McCann, M.S.
Lilac
Quick Reference
Pest Fact Sheet
Plant: Lilac, many ornamentals
Symptoms
Leaves/Plant: Yellow or brown discoloration and curling or shriveling of leaves. Leaves die and
drop off plant prematurely. White to gray powdery, flour-like growth on leaves, along with perhaps
tiny, white to black dots Distorted plant parts may be visible.
1
3
2
5
4
4
Disease: Powdery Mildew caused by Erisyphe syringae on lilac; other powdery
mildews specifically attack certain ornamentals.
Disease development conditions? Warm, dry weather promotes infection. Powdery mildews
can reproduce in 4-6 days at temperatures of 59-82oF. They may survive through winter and very
hot summers. Growth of powdery mildews is best in in humid air.
References
David McCann, M.S.
Disease: Chestnut Blight caused by Cryphonectria parasitica
Chestnut
Quick Reference
Pest Fact Sheet
Plant: Chestnut (Castanea spp.)
Symptoms and Signs
Swollen or sunken areas (cankers) created by the fungus may appear year-round under seemingly any
conditions. Cankers on smooth bark first appear as browned areas . Bark may split as disease develops
(1,2). Cankers on thick bark are less conspicuous unless swelling and cracking appears. Orange to
reddish-brown fungal growth breaks through the bark over time (3). Fungal fan-like growth may develop
under bark (4). Cankers are perennial and often found in branch axils. Water flow is disrupted and
dieback occurs beyond infections (5).
Disease development conditions: The fungus overwinters in infected tissue. Dispersal and infection
may occur year-round, particularly when bark is moist. Typically fresh wounds are infected as
susceptibility of wounds to infection decreases with time. Cankers may spread laterally 14-25cm per
year.
1
2
4
3
References
Anderson, R.L. 2000. USDA Forest Service, www.bugwood.org
Kunca,, A. 2002. National Forest Centre – Slovakia, www.bugwood.org
USDA Forest Service., Region 8 Archive. 2007. www.bugwood.org
5
Quick Reference
Pest Fact Sheet
Jordan E. Eggers
David P. McCann, MS
Insects and
their
Relatives
David McCann, M.S.
Pest: Aphids
General
Quick Reference
Pest Fact Sheet
Plant: Virtually all plants
Damage: Aphids have needle-like mouthparts that pierce plant cells and suck out contents. Leaves may have
clusters of yellow speckles, be yellowed or discolored overall, blistered, curled, wilted, distorted, or stunted (1, 2).
Shoots may be stunted, growth may be distorted, galls may be present, and flowers or fruit may be deformed.
Aphids may carry toxins in their saliva that promote further distortion and also may carry viruses and bacteria in
their saliva that cause plant disease.
Pest identification/life cycle: Aphids are about 1/16 inch long, pear shaped with long legs and antennae, and may
be green (3), red, yellow, brown, or black and sometimes thought to be black fleas on plants. Some produce a white
to gray wax or woolly covering. Most aphids are wingless but winged forms do appear, and most have cone shaped
structures at the rear of their body that distinguishes them from other insects (3). Aphids do not move quickly when
disturbed like most insects and generally aggregate and leave cast skins on the undersides of young plant parts (4).
Aphids release a sticky, sugary liquid (honeydew) that turns black as a mold (sooty mold) grows on it, thus plants
may turn black when covered with sooty mold. Also, ants are attracted to and feed on honeydew. Aphids have
many generations per year. Many aphid species are entirely female, with females giving birth (without mating) to
up to 80 living young within a week that mature in 7-10 days. In the fall aphids mate and produce eggs that
overwinter.
3
1
2
4
References
Flint. M.L. Ohlendorf, B. 2000. Pest note: aphids. University of California Agricultural and Natural Resources Publication 7404.
www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html
Townsend, L.. 2004. Aphids. University of Kentucky Cooperative Extension Publication ENTFACT-103. www.ca.uky.edu/entomology/entfacts/ef103.asp
David McCann, M.S.
Insect: Colorado Potato Beetle (CPB)
Plant: Potato, pepper, eggplant, tomato
Vegetables
Quick Reference
Pest Fact Sheet
Damage: CPB feeds on leaves of plants and adults occasionally sever stems of young emerging plants and kill
them. CPB chews holes in leaves or chews off the edges of leaves (1). Adult feeding is less severe than feeding of
larvae or worms (immature stage), but both can lead to loss of leaves, reduced yield, and death.
Pest identification/life cycle: CPB adults are about 1/8 inch in size and yellow with 10 black stripes on their back
(2). Larvae (immature stage) are about 1/2 inch, tan, pink, or red in color and humpbacked with rows of black spots
on each side (3). CPB overwinters in soil as an adult and emerges in spring as temperatures rise. When a plant is
found the beetles mate and females lay yellow-orange eggs on the underside of leaves in batches of around 20-35
(4). One female can lay 400-600 eggs in several weeks. Eggs hatch in 4-10 days and larvae begin feeding for 2-3
weeks before moving down to soil to transform into adults. There are 2-3 generations per year of CPB.
1
2
3
4
References
Dwyer, J.D., Dill, J.F., Carter, H.S. 2001. Colorado potato beetle Lepinotarsa decemlineata (Say) University of Maine Cooperative Extension Fact Sheet 201.
www.mainepotatoipm.com/ipmfactsheets/cpb.pdf
Bessin, R. 2004. Colorado potato beetle management. University of Kentucky Cooperative Extension Publication ENTFACT-312.
www.ca.uky.edu/entomology/entfacts/ef312.asp
David McCann, M.S.
Insect: Flea Beetles
General
Quick Reference
Pest Fact Sheet
Plant: Cabbage, corn, beans, beets, eggplant, lettuce, grapes, pumpkin, potato, spinach,
sweet potato, tomato, watermelon, and other fruits and vegetables.
Damage: On grasses, flea beetle feeding results in pale narrow areas running parallel to veins where green leaf
tissue has been removed and a clear membrane remains (1). These areas may zig-zag as beetles move across veins.
On broadleaf plants, flea beetles chew tiny circular holes between veins leaving a “shot-hole” appearance (2). Flea
beetles transmit Stewart’s Bacterial Wilt to corn.
Pest identification/life cycle: Adult beetles are small (about 1/16 of an inch long), shiny black, round-oval, (3) and
jump about like fleas when disturbed. Immature stages (larvae) are worm-like, 1/8-3/8 inches long, and dirty white
or gray with tiny legs and brown heads (4). Flea beetles overwinter under plant material as adults that emerge AprilMay and begin feeding: they are an early season pest problem. Eggs are laid on or in soil, leaves, petioles, and
stems and hatch in about 10 days. Larvae feed on roots, leaves or tubers for 3-4 weeks and rest in the soil for 7-10
days before transforming into adults. These “new” adults feed during late summer and fall before overwintering.
2
1
3
4
References
Calvin, D. 2000. Entomological Notes: Flea Beetle. Penn State Cooperative Extension Fact Sheet http://www.ento.psu.edu/Extension/factsheets/flea_beetle.htm
Eaton, A. 2000. Flea Beetles. University of New Hampshire Cooperative Extension http://extension.unh.edu/resources/files/Resource000549_Rep571.pdf
Kansas State University. 2003. Kansas State University Research and Extension Fact Sheet http://www.oznet.ksu.edu/hfrr/extensn/problems/fleabeet.htm
David McCann, M.S.
Insect: Mexican Bean Beetle (MBB)
Plant: Bean species, alfalfa, clover, peanut, okra, eggplant, squash,
Vegetables
Quick Reference
Pest Fact Sheet
Damage: Adults and larvae (immature stage) feed on leaves, pods, and stems. Early in their development larvae
feed exclusively on leaves. Adults and larvae feed on the underside of leaves, leaving the upper surface and veins in
tact and a characteristic lace-like appearance (1). Damaged bean pods also have a lace-like appearance. Heavy
infestations result in plant death.
Pest identification/life cycle: MBB adults are yellow to copper colored, oval, about 1/4 inch long, and have sixteen
black spots on their back (2). They resemble but are not lady bugs. Larvae are orange to yellow, oval, about 1/3
inch long and spiny or hairy (3). Eggs are about 1/20 inch, orange to yellow (4), and laid on leaf undersides in
clusters of 40-50 or more. MBB overwinters as adults on trees, fence lines, shrubs, and plant debris that become
active in the spring and lay eggs for 3-6 weeks after feeding for 1-2 weeks. Larvae hatch from eggs in 5-14 days
and mature in 2-5 weeks. Larvae then enter a resting stage, which is yellow to orange and partly spiny (4), and
transform into adults on leaf undersides within 7-10 days. Adults not overwintering live 4-6 weeks and there are
several generations a year depending on locality.
1
3
4
2
References
Ghidiu, G.M. 2005. Mexican bean beetle. North Carolina State University Cooperative Research and Extension fact Sheet FS227.
Ratcliffe, S.T., Gray. M.E., Steffy, K.L. 2004. Mexican bean beetle Epilachna varivestris. University of Illinois Extension Integrated Pest Management Fact Sheet.
http://ipm.illinois.edu/fieldcrops/insects/mexican_bean_beetle/index.html
Sorenson, K.A. 1994. Mexican bean beetle. North Carolina State University Cooperative Extension Insect Note #26 (revised).
www.ces.ncsu.edu/depts/ent/notes/Vegetables/veg26.html
David McCann, M.S.
Pest: Spider mites
General
Quick Reference
Pest Fact Sheet
Plant: Berries, flowering pants, fruit trees, ornamentals, vines, vegetables
Damage: Spider mites have needle-like mouthparts that pierce leaf cells and drain contents. Leaves fed on by
spider mites have yellow or white speckles that may converge resulting in yellow or bronzed foliage that may drop
off (1, 2, 3). Silky webbing spun by spider mites may cover leaves, twigs, or fruit (4). Spider mite damage is
compounded by water stress. Heavily infested plants may have reduced yield, be stunted, or die.
Pest identification/life cycle: Spider mites are close relatives of but are NOT insects. They are very small but may
be seen with a magnifying glass or by shaking plants over white sheets or paper. Spider mites have 8 legs (6 when
newly hatched), an oval body, and 2 red eyespots on their head (5). Females often have a spot on each side of their
body and are densely covered with hairs. Spider mites may be red, green, yellow, purple, black, or colorless
(transparent). Eggs are translucent becoming cream colored before hatching. Spider mites have many generations
per year, and under optimum temperatures (around 80o F) can reach maturity within 7-10 of hatching, thus their
populations can rapidly expand in hot weather, particularly from June-September. Most spider mites overwinter
as eggs, but some do so as adults.
1
4
5
3
2
References
Ohlendorf, B., Flint. M.L. 2000. Pest note: spider mites. University of California Agricultural and Natural Resources Publication 7405.
www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html
Shetlar, D.J. Spider mites and their control. Ohio State University Extension Fact Sheet HYG-2012-92. http://ohioline.osu.edu/hyg-fact/2000/2012.html
Short, D.E., Buss, E.A. 2008. Mites on ornamental plants. University of Florida Cooperative Extension Publication ENY-319. http://edis.ifas.ufl.edu/MG001
David McCann, M.S.
Iris
Quick Reference
Pest Fact Sheet
Insect: Iris borer
Plant: Iris
Damage: Worms of the iris borer make pin sized holes and tunnel into and feed inside leaves. Leaves develop tan
or water soaked spots and streaks and tips may turn brown (1) but entire plants rarely die from leaf damage. Worms
tunnel down to bulbs (2) where they can kill plants, doing the most damage to smaller bulb species. More
significant damage often is caused by bacteria that enter with worms and rot the bulb (3).
Pest identification/life cycle: Iris borers overwinter as eggs in plant debris, hatching April-May as new iris leaves
emerge. Worms are pink with brown heads and 1 ½ – 2 inches long (4), they enter leaves and tunnel to bulbs and by
August move into the soil to transform into a resting stage. Adults are brown moths with about a 2 inch wingspan
(5) and emerge from the soil in late August and September and lay eggs in clusters on iris leaves and stalks and
nearby plant debris.
1
2
3
4
5
References
Hahn, J. 2003. Yard and garden brief: iris borers. University of Minnesota Extension Service.
Pellitteri, P. 2005. University of Wisconsin garden facts, Iris borer. University of Wisconsin Extension.
Purdue University. 2009. Iris borer. Plant and Pest Digital Library Project, Purdue University.
Disease Image Bibliography
Tomato Diseases
Early Blight (Alternaria solani)
Image 1. Cornell University, Plant Disease Diagnostic Clinic,
http://www.pdis.org/ImageLibrary/ImageSearch.aspx
Image 2. Clemson University - USDA Cooperative Extension Slide Series, www.ipmimages.org.
Late Blight (Phytophthora infestans)
Image 1. Kent Loeffler, Cornell University, http://www.pdis.org/ImageLibrary/ImageSearch.aspx
Image 2. T. A. Zitter, Cornell University, http://vegetablemdonline.ppath.cornell.edu
Image 3. George Hudler, 2007, Cornell University,
Septoria Leaf Spot (Septoria lycopersici)
Image 1. Cornell University, Plant Disease Diagnostic Clinic,
Image 2. William M. Brown Jr., Colorado State University,
Image 3. Bruce Watt, 2006, University of Maine,
Potato Diseases
Late Blight (Phytophthora infestans)
Image 1. Howard F. Schwartz, Colorado State University,
Image 4. Scott Bauer, USDA Agricultural Research Service, www.ipmimages.org
Black Leg (Erwinia cartovora subsp. atroseptica)
Image 1. Clark Livingston, Colorado State University,
Image 2. Joseph P. Hill, Colorado State University,
Black Leg (Erwinia carotovora subsp. carotovora (ECC) and Erwinia carotovora subsp. atroseptica (ECA).
Image 1. The Royal Horticultural Society. 2009. http://www.rhs.org.uk/advicesearch/Profile.aspx?pid=223
Image 2. The Royal Horticultural Society. 2009. http://www.rhs.org.uk/advicesearch/Profile.aspx?pid=223
Images 3 and 4. Rowe, R.C., Miller S.A., Riedel, R.M. 2009. Blackleg, aerial stem rot, and tuber soft rot of
potato. Ohio State University Extension Fact Sheet HYG-3106-95.
http://ohioline.osu.edu/hyg- fact/3000/3106.html
Image 5. United Nations Economic Commission for Europe. 2008.
http://www.unece.org/trade/agr/standard/potatoes/ListofPestPictures/BlackLeg/BlackLeg_Tuber1.jpg
Bean Diseases
Fusarium and Rhizoctonia Root Rot (Fusarimu solani and Rhizoctonia solani)
Damping Off or Pythium Root Rot (Pythium spp.)
Image 1. David B. Langston, University of Georgia, www.ipmimages.org
Anthracnose (Colletotrichum lindemuthianum)
Image 1. T.A. Zitter, Cornell University,
http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Impt_Diseases/Beans/Bea
n_Anthrac.htm
Image 2. Cornell University:
n_Anthrac.htm
Image 3. T.A. Zitter:
n_Anthrac.htm
Image 4. Clemson University - USDA Cooperative Extension Slide Series,
www.ipmimages.org
Sclerotinia Rot or White Mold (Sclerotinia sclerotiorum)
Image 1. David B. Langston, University of Georgia, www.ipmimages.org
Bean Common Mosaic Virus
Bean Yellow Mosaic Virus
Image 3. T. A. Zitter, Cornell University,
http://vegetablemdonline.ppath.cornell.edu/PhotoPages/CropHosts/Beans.htm
Corn Diseases
Smut (Ustilago maydis)
www.Bugwood.org
www.Bugwood.org
www.Bugwood.org
Bacterial Wilt, Stewart’s Wilt (Erwinia stewrtii)
Image 1. A.J. Ullstrup, www.Bugwood.org
Image 4. J.K. Pataky, University of Illinois at Urbana-Champaign, www.Bugwood.org
Maize Dwarf Mosaic Virus
www.Bugwood.org
Pepper Diseases
Bacterial Leaf Spot (Xanthomonas campestris pv. vesicatoria)
www.Bugwood.org
Image 3. Volcani Center Archives, Agricultural Research Organization,
www.Bugwood.org
Image 4. David B. Langston, University of Georgia, www.Bugwood.org
Anthracnose Fruit Rot (Colletotrichum acutatum)
Cabbage Diseases
Black Rot (Xanthomonas campestris pv. campestris)
Onion Diseases
Purple Blotch (Alternaria porri)
Image 1. Chaput , J. 1995. Identification of Diseases and Disorders of Onions
www.omafra.gov.on.ca/.../crops/facts/95-063.htm
Image 2. Schwartz, H.F. 2008. Botrytis, Downy Mildew and Purple Blotch of Onion Colorado State
University Extension Pub lication No. 2.941
Image 3. Elliott, B., Northover, P. 2005. Manitoba Weekly Vegetable Report Issue 10. Manitoba
Agriculture, Food and Rural Initiatives Soils and Crops Branch, Carman
Image 4. Graper, D.F. 2000. Pest Alert. hflp.sdstate.edu/Pestalrt/alert906.htm
Image 5. Gerlach W. 2009. www.infonet-biovision.org/default/ct/125/crops
Downey Mildew (Peronospora destructor)
Image 1. Lorbeer, J.W., Andaloro, J.T. 1984. Cornell University Cooperative Extension Fact Sheet
Page 737.20.
Image 2. Allen, J. 2006. Downy mildew in onions. www.omafra.gov.on.ca/.../2006/16hrt06a2.htm
Image 3. Kennedy, R., Clarkson, J. 2009. www.hri.ac.uk/site2/research/path/pathogen.htm
Image 4. Putnam, M. 2001. www.ag.uidaho.edu/.../onion_diseases.htm htm
Page 737.20.
Botrytis Leaf Blight (Botrytis squamosa)
Image 1. Allen, J. 2007. Onion Diseases: what to look for .
www.omafra.gov.on.ca/.../2007/16hrt07a3.htm
Image 2. Kennedy, R., Clarkson, J. 2009. www.hri.ac.uk/site2/research/path/pathogen.htm
Image 3. Allen, J. 2005. Botrytis leaf blight in onions.
www.omafra.gov.on.ca/.../2005/16hrt05a2.htm
Page 737.10.
Page 737.10.
Neck Rot (Botrytis squamosa, B. allii, and B. cinerea)
Image 1. http://www.vegetable-garden-guide.com/images/neck-rot2.jpg 2009.
Image 2. Edwards, D. 2006.
http://postharvest.ucdavis.edu/Produce/ProduceFacts/Veg/onionneckrot.gif
Image 3. Chaput , J. 1995. Identification of Diseases and Disorders of Onions
www.omafra.gov.on.ca/.../crops/facts/95-063.htm
Image 4. . Boyhan, G.E., Kelley , W.T. 2008. Onion Production Guide University of Georgia
Extension Publication B 1198-2.
Image 5. Sherf, A.F. Cornell University. 2009.
http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Impt_Diseases/Onion/Onion_Neck.ht
m
Vegetable Diseases
Grey Mold (Botrytis cinerea)
Image 1. Salem Khalil Nassr. APS publication number: IW000077
http://www.apsnet.org/online/Archive/2007/iw000077.asp
Image 2. BBC magazine http://www.gardenersworld.com/how-to/problem-solving/lettucegrey-mould/main.jpg
Image 3. http://www.garden.ie/gardeningtroubles.aspx?id=668
Image 4. BBC. 2009.
http://www.bbc.co.uk/gardening/advice/pests_and_diseases/images/medium/grey_mould
_on_tomato_stem.jpg
Image 5. Netherlands Organization for Scientific Research. 2007.
http://www.sciencedaily.com/releases/2007/04/070413094029.htm
Fruit Diseases
Grey Mold (Botrytis cinerea)
Image 1. Hypermedia en Protection des Plantes. 2008.
http://www.inra.fr/hyp3/pathogene/6botci8.htm
Image 2. Peerbolt, T. 2009.
http://www.nwipm.info/PhotosByTypes.asp?BerryCatName=Strawberries&BerryCatDisor
derName=Disease
http://postharvest.ucdavis.edu/produce/producefacts/fruit/peachnectgreymold2.gif
http://postharvest.ucdavis.edu/produce/producefacts/Fruit/pearanjGrayMoldRot.gif
Image 5. Hypermedia en Protection des Plantes. 2008.
http://www.inra.fr/hyp3/images/6030631.jpg
Apple Diseases
Apple Scab (Venturia inaequalis)
Image 1. Bruce Watt, 2004, University of Maine, http://www.pdis.org/ImageLibrary
Image 2. Joseph O'Brien, USDA Forest Service, www.Bugwood.org
www.Bugwood.org
www.Bugwood.org
Apple Rust (Gymnosporangium juniperi-virginianae)
Image 1. George Hudler, 2006, Cornell University, http://www.pdis.org/ImageLibrary
Image 2. George Hudler, 2006, Cornell University, http://www.pdis.org/ImageLibrary
Image 3. Brian Olson, 2004, Oklahoma State University,
http://www.pdis.org/ImageLibrary
Image 4. Brian Olson, 2004, Oklahoma State University,
Apple Fire Blight (Erwinia amylovora)
Image 1. William M. Ciesla, Forest Health Management International,
www.Bugwood.org
Image 2. Ward Upham, 2007, Kansas State University
www.Bugwood.org
Fire Blight (Erwinia amylovora)
Image 1. P.W. Steiner, West Virginia University,
http://www.caf.wvu.edu/kearneysville/disease_descriptions/omblight.html
Image 2. K.D. Hickey, West Virginia University,
Image 3. Wayne A. Sinclair and Howard H. Lyon. 2005. Diseases of trees and shrubs,
second edition. Cornell University Press, Ithaca, NY.
Image 4. Alan Biggs, West Virginia University,
Black Rot (“fog-eye” leaf spot; Botryosphaeria obtusa)
Image 3. J.W. Travis . 2008, West Virginia University
http://www.caf.wvu.edu/kearneysville/disease_descriptions/omblackr.html
Image 4. J.W. Travis . 2008, West Virginia University
http://www.caf.wvu.edu/kearneysville/disease_descriptions/omblackr.html
Image 5. : Alan R. Biggs. 2008. West Virginia University.
www.caf.wvu.edu/.../viskeyafr.html
Peach Diseases
Brown Rot (Monilinia fruiticola and M. taxa)
http://www.caf.wvu.edu/Kearneysville/disease_descriptions/ombrownr.html
Bacterial Spot/Shot Hole (Xanthomonas campestris pv. Pruni)
Image 1. J. Springer, West Virginia University,
http://www.caf.wvu.edu/Kearneysville/disease_descriptions/ombactsp.html
Image 2. H.L. Keil, USDA Forest Service, www.Bugwood.org
http://www.caf.wvu.edu/Kearneysville/disease_descriptions/ombactsp.html
Image 4. . Wayne A. Sinclair and Howard H. Lyon. 2005. Diseases of trees and shrubs,
Cherry, Plum, Prune Diseases
Black Knot (Apiosporina morbosa)
Image 2. Bill Hilton Jr. www.hiltonpond.org
Firethorn Diseases
Pyracantha Scab (Venturia inequalis f.sp. pyracanthae)
Image 2. University of Illinois,
http://www.ipm.uiuc.edu/diseases/series600/rpd638/index.html
Image 3. University of Illinois,
http://www.ipm.uiuc.edu/diseases/series600/rpd638/index.html
Flower Diseases
Rose Black Spot (Diplocarpon rosae)
Image 1. Plant Disease Diagnostic Clinic, 2006, Cornell University
Image 2. Ward Upham, 2007, Kansas State University
Image 3. Bruce Watt, 2006, University of Maine, http://www.pdis.org/ImageLibrary
Rose Black Spot 2 (Diplocarpon rosae)
Image 1. University of Delaware Cooperative Extension, Iowa State University Plant
Disease Clinic. 2007
Image 2. eHow How to Prune Overgrown Roses. 2009.
http://i.ehow.com/images/GlobalPhoto/Articles/4615456/rose-black-spot_Full.jpg
Image 3. Marin Rose Society. 2006. http://www.marinrose.org/blackspot.jpg
Image 4. Royal Horticultural Society
http://www.rhs.org.uk/Learning/research/images/ph_blackspot_winter.jpg
Rose Black Powdery Mildew (Sphaeotheca pannosa)
Image 1HR Communicator, Inc. 2007.
http://www.greencure.net/images/powdery_mildew_on_rose.jpg
Image 2. Gardening Blog. 2008. http://cfs.nrcan.gc.ca/images/7630
Image 3. Pearce. M. 2005. Rose Disease in the landscape. The University of Georgia
Cooperative Extension.
Image 4. http://www.ces.ncsu.edu/depts/pp/notes/Ornamental/odin004/rosepmc2.jpg
Chrysanthemum White Rust (Puccinia horiana)
Image 1. Division of Plant Industry Archive, Florida Department of Agriculture and
Consumer Services, www.Bugwood.org
Image 4. Daniel J. Kepich, USDA APHIS PPQ, www.Bugwood.org
Zinnia
Bacterial Leaf Spot (Xanthomonas campestris sub. sp. zinniae)
Image 1. I. Schwarczinger * L. Vajna and S. SÃ¼le. 2007. First report of bacterial leaf and
flower spot of Zinnia elegans caused by Xanthomonas campestris pv. zinniae in
HungaryNew disaes reports 15
Image 2. University of Delaware Cooperative Extension. 2007.
http://4.bp.blogspot.com/_8xC9bwq6AVU/Rpga2-e2CI/AAAAAAAAACM/5TK7CkAR7Pg/s1600-h/bacterialleafspotzinnia.JPG
Image 3. Missouri botanical garden. 2009.
http://www.mobot.org/gardeninghelp/images/Pests/Pest141.jpg
Image 4. Virginia Cooperative Extension Plant problem Image Gallery. 2009.
Alternaria Leaf Spot (Alternaria zinniae)
Image 1. Roos, D. 2006. North Carolina Cooperative Extension
http://www.ces.ncsu.edu/chatham/ag/SustAg/GSFgraphics/bacspotzinniaweb.jpg
Image 2. Roos, D. 2006. North Carolina Cooperative Extension
http://www.ces.ncsu.edu/chatham/ag/SustAg/zinnialeafspot.html
Phlox
Septoria Leaf Spot (Septoria spp.)
Image 1. Pundt., L.2006. University on Connecticutt IPM.
Image 2. Robbins, J. 2007. University of Arkansas Cooperative Extension
http://plantpathology.uark.edu/Number7-2007.pdf
Image 3. Jacobi, W. 2008. Colorado State University, www.Bugwood.org
Image 4. Sherrie S. 2007. University of Arkansas Cooperative Extension
http://plantpathology.uark.edu/Number7-2007.pdf
Powdery Mildew (Erysiphe cichoracearum)
Image 1The Dow Gardens Archive. 2007. Dow Gardens, www.Bugwood.org
Image 2. University of Wisconsin.
http://www.hort.wisc.edu/mastergardener/features/diseases/powderymildew/pm%20phlox
2.jpg
Image 3. http://www.plantesygdomme.dk/melduglogo.jpg
Iris
Iris Leaf Spot (Heterosporium iridis)
Image 1. Pscheidt, W. 2006. http://plantdisease.ippc.orst.edu/plant_images/IrisLeafSpotSunshineBehind.jpg
Image 2. Rodrigue, N., Rodrigue, R. 2009. http://rodrigue.org/iris/howtogrowiris.htm
Image 3. McCann, D. 2009. West Virginia University Extension
Image 4.Graper, D.F. 1999. http://hflp.sdstate.edu/Pestalrt/alert805.htm
Tree Diseases
Bacterial Wet Wood (Enterobacter cloacae, other bacteria, yeasts, and other fungi.)
Image 1. Edward L. Barnard, Florida Department of Agriculture and Consumer
Services, www.Bugwood.org
Image 2. Fred Baker, Utah State University, www.Bugwood.org
Armillaria Root Disease – Shoestring Root Rot (Armillaria species)
Image 1. USDA Forest Service, Ogden Archive. 1983. www.Bugwood.org
Image 2. Joseph O'Brien. USDA Forest Service. 2007. www.Bugwood.org
Image 3. William Jacobi.,Colorado State University. 2008. www.Bugwood.org
Image 4. Linda Haugen, USDA Forest Service. 2005. www.Bugwood.org
Heart Rot (Oxyporus populinus)
Image 2. Minnesota Department of Natural Resources Archive. 2007. Minnesota
Department of Natural Resources. www.Bugwood.org
Root Rot (Heterobasidion annosum)
Image 3. Mistretta, P.A. 2007. USDA Forest Service, www.Bugwood.org
Image 4. USDA Forest Service - Region 8 Archive. 2007. USDA Forest Service.
www.Bugwood.org
Tinder Fungus (Fomes fomentarius)
Image 1. Kunca,, A. 2009. National Forest Centre - Slovakia, www.Bugwood.org
Image 2. Frank, N. 2009. University of West Hungary. www.Bugwood.org
Image 3. Kunca,, A. 2009. National Forest Centre - Slovakia, www.Bugwood.org
Image 4. Wojciech, G. 2004. Polish Forest Research Institute, www.Bugwood.org
Dogwood Diseases
Dogwood Anthracnose (Discula destructiva)
Image 1. Robert L. Anderson, USDA Forest Service, www.Bugwood.org
www.Bugwood.org
Maple Diseases
Maple Tar Spot (Rhytisma spp.)
Image 1. Andrej Kunca, National Forest Centre - Slovakia, www.Bugwood.org
Image 2. Andrej Kunca, National Forest Centre - Slovakia, www.Bugwood.org
Image 3. Steven Katovich, USDA Forest Service, www.Bugwood.org
Phyllosticta Leaf Spot (Phyllosticta minima)
Maple Anthracnose (Discula spp.)
Image 1. Cornell University, 1994, Plant Disease Diagnostic Clinic,
Image 2. Ward Upham, 2005, Kansas State University,
Image 3. Minnesota Department of Natural Resources Archive, Minnesota Department
of Natural Resources, www.Bugwood.org
Verticillium Wilt (Verticillium albo-atrum and V. dahliae)
Elm Diseases
Dutch Elm Disease (Ophiostoma ulmi)
Image 2. Petr Kapitola, State Phytosanitary Administration, www.Bugwood.org
of Natural Resources, www.Bugwood.org
Oak Diseases
Oak Wilt (Ceratocystis fagacearum)
of Natural Resources, Bugwood.org
Image 3. T.W. Bretz, USDA Forest Service, www.Bugwood.org
Image 4. D. W. French, University of Minnesota, www.Bugwood.org
Image 5. Fred Baker, Utah State University, www.Bugwood.org
Oak Anthracnose (Discula quercinia)
Image 1. Petr Kapitola, State Phytosanitary Administration, www.Bugwood.org
Image 2. North Carolina Forest Service Archive, www.Bugwood.org
Image 4. Steven Katovich, USDA Forest Service, www.Bugwood.org
Oak Leaf Blister (Taphrina caerulescens)
Image 2. Michael Kangas, NDSU - North Dakota Forest Service, www.Bugwood.org
Image 4. Paul H. Peacher, USDA Forest Service, FIDM/FPM, www.Bugwood.org
Juniper Diseases
Juniper Twig Blight (Kabatina juniperi)
Juniper Twig Dieback (Phomopsis juniperovora)
Lilac/Ornamental Diseases
Powdery Mildew (Erisyphe syringae on Lilac; specific genera for ornamentals)
Chestnut Diseases
Chestnut Blight (Cryphonectria parasitica)
Image 2. USDA Forest Service., Region 8 Archive. 2007. www.bugwood.org
Image 3. Robert L. Anderson. 2000. USDA Forest Service, www.bugwood.org
Image 4. Andrej Kunca. 2002. National Forest Centre – Slovakia, www.bugwood.org
Image 5. Andrej Kunca. 2002. National Forest Centre – Slovakia, www.bugwood.org
Insects and their Relatives Image Bibliography
General Pests
Aphids
Image 1. Masiuk, M. Aphid fact sheet.
http://woodypests.cas.psu.edu/Insects/Aphid/BirchAphidDamage.jpg
Image 2. British Columbia Ministry of Agriculture and Lands. 2006.
http://www.agf.gov.bc.ca/cropprot/tfipm/images/rosyappleleaves.jpg
Image 3. Harris, M. 2004.
http://www.extension.iastate.edu/newsrel/reiman/AphidClose.jpg
Image 4. Roos, D. 2008.
http://www.ces.ncsu.edu/chatham/ag/SustAg/GSFgraphics/aphids05.jpg
Colorado Potato Beetle
Image 1. Hahn, J. 2008.
http://www.extension.umn.edu/projects/yardandgarden/YGLNews/images2/July152008/cob
eetle1_600px.jpg
Image 2. Bessin, R. 2004. Colorado potato beetle management. University of
Kentucky Cooperative Extension Publication ENTFACT-312.
www.ca.uky.edu/entomology/entfacts/ef312.asp
Image 3. Dill J.F. 2001. Colorado potato beetle Lepinotarsa decemlineata (Say) University of
Maine Cooperative Extension Fact Sheet 201.
Image 4. Dill J.F. 2001. Colorado potato beetle Lepinotarsa decemlineata (Say) University of
Maine Cooperative Extension Fact Sheet 201.
Flea Beetles
Image 1. Rice, M.E. 1997. Iowa State University Entomomlogy Department.
http://www.cornellcollege.edu/biology/insects2003/davidmichael/images/fleabeetle.jpg
Image 2. Young, D. 2008.
http://www.donnayoung.org/blog/2008/05/15/aphids-and-flea-beetles/
Image 3. Kansas State University. 2003. Kansas State University Research and Extension
Fact Sheet. http://www.oznet.ksu.edu/hfrr/extensn/problems/fleabeet.htm
Image 4. Galvan T.L.,Burkness, E.C., Hutchison, W.D. Grape flea beetle. 2009. Extension
Service, University of Minnesota.
http://www.vegedge.umn.edu/vegpest/grapes/FleaBeetle.htm
Insects and their Relatives Image Bibliography
General Pests
Mexican Bean Beetle
Image 1. Reidy, J. 2008.http://farm3.static.flickr.com/2249/2787059272_f031427ed1.jpg?v=0
Image 2. Castner, J. 2009. University of Florida
http://entomology.ifas.ufl.edu/creatures/veg/bean/mexb1.jpg
Image 3. Castner, J. 2009. University of Florida
http://entomology.ifas.ufl.edu/creatures/veg/bean/mexb2.jpg
Image 4. Clemson University. Dept of Entomology, Soils, and Plant Sciences.
http://entweb.clemson.edu/cuentres/cesheets/veg/ce27.jpg
Mites
Image 1. Clemson University - USDA Cooperative Extension Slide Series. Bugwood.org
Image 2. Masiuk, M. 2003.
http://woodypests.cas.psu.edu/Insects/SpruceSpiderMite/Spruce_Spider_Mite_Arbor.jpg
Image 3.
Image 4. Clemson University. 2003. USDA Cooperative Extension Slide Series, ,
www.insectimages.org
Image 5. David Cappaert, Michigan State University, Bugwood.org
Iris
Iris Borer
Image 1. University of Wisconsin. 2000.
http://www.extension.umn.edu/yardandgarden/YGLNews/images/irisborerdamage-uwi.jpg
Image 2. Rodrigue, N., Rodrigue, R. 2009. http://rodrigue.org/iris/howtogrowiris.htm
Image 3. http://z.about.com/d/gardening/1/0/R/4/IrisDamage.jpg
Image 4. Gwilliam, J. 2009. http://www.hort.net/lists/irisphotos/aug08/msg00055/iris_borer_larva.jpeg
Image 5. McLeod, R. 2004. http://bugguide.net/node/view/11175

Plant Disease Fact Sheet - WVU Ext

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