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Entomology 101
Insect Products
& Biological Benefits
Can you name any products you have
used that came from insects?
• Honey?
• Beeswax?
David J. Shetlar, Ph.D.
The “BugDoc”
• Silk?
The Ohio State University,
OARDC & OSU Extension
Columbus, OH
© November, 2009, D.J. Shetlar, all rights reserved
Insects also produce:
Honey
• Lac > Shellac
• Honey collecting and bee keeping – very
ancient activities!
• Dyes > direct & indirect
• Cave drawings in Valencia, Spain show
honey gatherers (ca 15-7000 BC!)
• Drugs!
• Royal Jelly
• Venom therapy
• Cantharidin (Spanish Fly!)
Honey
• True honey bee care seems to date to
about 2600-2400BC in lower Egypt.
Honey bee colonies were kept in baskets
with clay tops or clay cylinders.
Honey
•
Clay pots used in Egypt, Greece, and Rome
until about 1400 AD.
•
Anglo Saxons developed straw SKEP in 1400s.
•
1650 – first octagonal hive with wood supers
(England).
•
1675 – first removable comb frames.
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Honey
Modern
honey
bee hive
box.
Honey
•
Honey is a high sugar, low water, viscous liquid
derived primarily from flower nectar.
•
Nectar is taken from flowers into bee sac (crop)
and is mixed with salivary secretions. This is
regurgitated to other bees in nest which dehydrate
it by spreading onto a surface or expanding and
retracting droplets with mouthparts.
•
Ripe honey has 20% or less water.
•
Ripe honey is stored in cells and capped with wax.
•
Honey derives flavors from fragrances and floral
chemicals found in original nectar.
•
High sugar suppresses bacteria and low water
suppresses fungi.
Honey
•
•
Beeswax
Mature hive can produce up to 500 pounds of
honey per summer, yet only 50 pounds is needed
for winter survival!
•
Produced by glands in the exoskeleton of
bees’ abdomens.
Honey Types –
•
Used by bees for hive construction
(keeping larvae, pollen and honey)
•
Low melting point (~147ºF)
• Chunk or comb
• Liquid (different flavors)
• Used in candles
• Creamed
• Cosmetics
• Polish (old furniture finishes)
Silk
•
Many insects produce silk, but only the silkworm
moth, Bombyx mori, produces a silk cocoon
using a single thread that can be unwound!
•
Sericulture (culture of the silkworm moth for silk)
is believed to have been developed in China
around 1700 BC!
•
Japan, China, Russia, India, and South Korea are
major producers today.
•
Takes about 110 cocoons for a necktie and over
600 for a shirt!
Silkworm Life Cycle
Adult female & male
Pupa in Cocoon
Eggs
Takes 5-6 weeks to
complete cycle.
Pupae are killed when
silk is harvested!
Cocoon
Larvae eat
mulberry
leaves.
Images: M. Desamdoes
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Shellac
•
Resin secreted by a tiny scale, Laccifer lacca a native
of India and Burma, often coats the branches of host
trees (soapberry and Acacia).
•
Coated branches (sticklac) are collected and heated
to melt the resin. The resin scrapings are crushed
into small flakes. The flakes are soluble in alcohol,
which makes shellac.
•
Shellac has been used for centuries to cover wooden
surfaces. Fine antiques and violins were often
painted with shellac.
•
Shellac is non-toxic and is a good, clear coating for
children’s items and furniture. Modern polyurethane
and other synthetics have taken the place of shellac.
Shellac
Lac scales coating branch
Sticklac
Various steps and grades of lac.
Dyes from Insects
•
Cochineal is a scarlet pigment extracted from
Dactylopius coccus, a scale that infests cactus in
Mexico and Central America.
•
Scale bodies are scraped off cactus, dried and
crushed into a powder. This is extracted through a
complicated chemical process after which the
solution can be used as a dye.
•
The British “Redcoats” had their coats stained with
cochineal!
•
Cochineal (or carmine) is still produced today and is
used in foods, cosmetics and as dyes for certain
fibers. It takes 70,000 insects to make a pound of dye!
Dyes from Insects
•
Iron-Gall Ink is technically not an insect but the
product of insect activity! Oak bullet or marble galls
are produced by parasitic wasps that force oak trees
to produce abnormal, woody growths on oak
branches.
•
The galls contain tannins and pigments which in the
presence of iron ions turn a dark, permanent black
color. This was the main ink used by colonists and is
most likely the ink used to copy the U.S. Constitution!
•
Many oak galls are also used to extract tannic acid
which is used to tan hides!
The little patches of waxy material on this prickly pear
cactus are cochineal scales!
Swamp White Oak seedling
covered with oak bullet
galls. These can be used
to produce black ink!
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Drugs from Bugs??!
•
Spanish Fly is probably the most famous (or is that
infamous) drug derived from an insect, a blister
beetle that is native to Europe!
•
Lytta vesicatoria is in the family Cantharidae, and
beetles of this family produce a set of chemicals
called cantharides.
•
Cantharides are blistering agents and can be used to
burn off warts and remove tattoos.
•
However, if ingested, cantharides are removed by the
kidneys and excretion causes a burning of the
urethra and external genitals. Too much cantharides
can cause permanent kidney damage!
Photo: Wikimedia Commons
Lytta vesicatoria is a rather pretty beetle!
Drugs from Bugs??!
•
Other Benefits from Insects
Bee sting therapy is commonly used and even
prescribed for pain relief and arthritis
suppression!
• POLLINATION!
•
Recent findings have isolated some fungicidal
compounds produced by insects.
• Natural/Biological Control of
Pestiferous Insects
•
Asian cultures have used ground up insects of all
types for “folk remedies!”
•
Each insect has evolved to deal with its
environment including parasites, predators and
diseases. Most insects have developed chemical
molecules to assist in this effort and many
pharmaceutical companies are just not beginning
to investigate them!
Pollination – transfer of the pollen from “male” anther
of a flower to the “female” stamen of a flower of a plant of the
same species.
• Important Components of
Ecosystems
• Food for other animals
• Detritivores
• Carrion Disposal
• Bio-indicators of Quality
Pollination Types
•
Abiotic – doesn’t involve an organism (usually
wind and rarely water)
•
•
•
•
Most conifers
Most grasses (small grains) and sedges
About 12% of flowering plants
Biotic – pollen transferred by an organism
•
•
Most flowering plants
Mainly insects, but also birds, bats and a few
other animals.
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Characteristics of WindPollinated Plants
•
Flowers lack bright colors, odors and
nectar.
•
•
•
Flowers small, usually without petals.
•
Stigma feathery
Douglas-fir seed and flower cones
Lots of pollen produced
Pollen small and light, occasionally
with projections
Plant Strategies for Biotic Pollination
•
•
•
•
•
Food (nectar & pollen)
Scents (sweet, rotten)
Visual Cues (to get to the food!)
Mimicry (lure insects in)
Entrapment (lure insects in and
temporarily trap them in order to coat
them with pollen)
Most grasses & grass crops (wheat, rice, barley, corn) are wind pollinated.
Insect Pollinators (the cast)
•
•
•
•
•
•
Worker with full pollen bag
Bees (the top specialists!)
Flies
Wasps & Ants
Beetles
Butterflies & Moths
Others (thrips, bugs)
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Leafcutter bees carry pollen on abdominal hairs!
A cluster fly covered with pollen.
Fungus gnat adult.
Wedge beetle feeding in flower.
Locust borer in goldenrod
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Classic Insect Biocontrols
Chinese mantis, a
common imported
predator
■ Predators
Ants & Wasps
Beetles
Spiders
Bugs (damsel, bigeyed, stink)
Mites
Others
■ Parasites
Wasps
Flies
■ Pathogens
Bacteria
Fungi
Virus
Entomopathogenic Nematodes
Convergent lady
beetle eating
aphids
What is this?
This is the larva of an
imported cabbageworm
which has just been
killed by wasp parasites.
The parasites have
emerged and pupated in
a mass next to the host
body.
Aphid wasps are small black
wasps that lay eggs in the
bodies of aphids. Upon
completing development, the
wasp larva causes the aphid
body to swell into an aphid
“mummy.”
This remains of a cabbage
looper is filled with the
mature larvae of a unique
wasp. Only one egg was
laid! The embryos divide
until they fill the body
cavity!
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