Improving rearing and establishment success of the air potato leaf

Improving rearing and establishment success of the air potato leaf

Improving rearing and establishment success of
the air potato leaf beetle by closing knowledge
gaps in its biology and geographic adaptation
W. A. Overholt1, V. Manrique1, R. Diaz, M. Smith2, E. Lake2 and P. Tipping2
1Indian
River Research and Education Center, UF/IFAS, Fort Pierce, FL
2Invasive Plant Research Laboratory, USDA/ARS, Fort Lauderdale, FL
Objectives
• Investigate temperature-dependent development
and construct life tables for the Chinese and
Nepalese biotypes of Lilioceris cheni.
• Determine conditions for diapause induction
studies with the two L. cheni biotypes.
• Examine overwintering survival of the two
biotypes at different latitudes in Florida.
• Compare the cold tolerance of two L. cheni
biotypes.
Discovery of Lilioceris cheni
(Coleoptera: Chrysomelidae)
• Releases of the Chinese biotype were
initiated in FL in Nov 2011
Nepalese biotype (2002)
Chinese biotype (2011)
USDA-ARS IRPL Ft. Lauderdale
Center et al. 2013
Temperature-dependent development
Fresh eggs, 5 neonates per Petri dish
(30 replicates per temperature)
Seven constant temperatures:
10, 15, 20, 25, 27.5, 30, 35° C
60-70% RH, 14L: 10D
photoperiod
Variables recorded:
• Time of development (days)
• Survival to each stage
• Lifetime fecundity and longevity of
adult pairs (separate)
Chinese
Nepalese
Higher survival of Chinese at 25 and 27.5°C
Percent survival to adult
a
100
80
Chinese
a
b
60
b
Nepalese
40
20
0
20
25
27.5
30
Temperature (°C)
Faster development of Nepalese at 20, 25C
60
40
Development egg to adult (days)
a
Chinese
b
Nepalese
a b
20
0
20
25
27.5
30
Temperature (°C)
High reproductive rate
• Fecundity:
• China 1900 eggs per female
• Nepal: 900 eggs per female
Chinese biotype
Mean eggs/Nepal female
600
600
500
500
Number of eggs
Number of eggs
Means eggs/China female
400
300
200
100
400
300
200
100
0
1
4
8
12
16
Age (weeks)
20
24
40
0
0
4
8
12
16
Age (weeks)
20
24
28
Adult longevity
a
Life table statistics
Parameter
Chinese
Nepalese
Net reproductive
rate (Ro)
Intrinsic rate of
increase (rm)
Generation time (T)
700.67
224.88
0.46
0.64
14.26
8.49
Diapause induction
Newly emerged adults
10-15 adults per container
Photoperiod
Short Days (10L: 14D)
Long Days (14L: 10D)
x
Temperature
20°C and 25°C
Dissections after 15 and 40 days
•
•
•
Fat body content
Digestive system
Reproductive system
Dissections of Lilioceris cheni
Diapause females
20°C and short days
Non-diapause females
20°C long days
25°C short and long
days
Diapause induction
Long = 14L: 10D
Short = 10L: 14D
Temperature
OC
Photoperiod
L:D
Status
Chinese
25
Long
Active
Nepalese
25
Long
Active
Chinese
25
Short
Active
Nepalese
25
Short
Active
Chinese
20
Long
Active
Nepalese
20
Long
Active
Chinese
20
Short
Diapause
Nepalese
20
Short
Diapause
Population
Overwintering survival in the field
Field sites along a latitudinal gradient
T°
Tallahassee
Ft. Pierce
Homestead
Chinese biotype
Nepalese biotype
• 10 cages with Chinese biotype
• 10 cages with Nepalese biotype
• 25 adults per cage
• Sampling monthly from Oct 2013 to
May 2014
USDA Plant Hardiness Zones
Adults per cage
Adult survival: Ft Pierce > Tallahassee > Homestead
20
chinese
53% Nepalese
15% Chinese
0
Adults per cage
Adults per cage
25
20
15
10
5
0
http://planthardiness.ars.usda.gov/PHZMWeb/#
Tallahassee
25
20
15
10
5
0
Fort Pierce
46% survival
Homestead
7% Nepalese
0% Chinese
No food – plants die back
in cages
20
Homestead
China
15
Nepal
10
5
0
15
Fort Pierce
10
5
Dundee
0
20
15
10
5
0
20
Tallahassee
15
10
5
eb-15
eb-15
an-15
ec-14
ec-14
ov-14
ct-14
0
ct-14
Overwintering 2014-15
Conclusions
•
Higher survival of Chinese at higher temperatures (25, 27.5°C)
•
Faster development of Nepalese
•
High reproductive potential and long lived adults (5-8 months)
•
Intrinsic rate of increase higher for Nepalese beetles
Tallahassee: 53% Nepalese > 15% Chinese
Ft. Pierce: ~46% survival
Homestead: 7% Nepalese > 0% Chinese
Releases by FDACS/DPI, USDA/ARS and UF/IFAS
Beetles released
DPI: 145,959
USDA: 167,367
UF: 8,750
USDA
DPI
UF
Total: 322,076
Number of locations
DPI: 599
USDA: 257
UF: 153
Total: 1010
Questions?