anthony hanson1 2and rob venette - bugwoodcloud...anthony hanson1 2and rob venette 1university of...
Post on 08-Aug-2020
9 Views
Preview:
TRANSCRIPT
Anthony Hanson1 and Rob Venette2 1University of Minnesota (hans4022@umn.edu)
2USDA Forest Service Northern Research Station (rvenette@fs.fed.us)
Emerald Ash Borer in the Midwest Agrilus planipennis Fairmaire
(Coleoptera: Buprestidae)
First discovered in North America near Detroit, MI in 2002 (Poland and McCullough 2006).
Discovered in Minnesota in 2009. Northwestern edge of invasion front.
United States Ash Density
http://extension.entm.purdue.edu/eab/images/ashLocations_sm.jpg
Emerald Ash Borer Parasitoids
Spathius agrili Yang, (Hymenoptera: Braconidae) 3.4 to 4.3 mm.
Tetrastichus planipennisi Yang, (Hymenoptera: Eulophidae) 1.6 to 4.1 mm.
Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) 0.95 mm. • Approved for release in by APHIS-PPQ in 2007.
• Parasitoids introduced and successfully overwintered in Michigan and Maryland (Ulyshen et al. 2011, Bauer & Liu 2007).
• Extent of cold tolerance is unknown.
Why is cold tolerance important?
Objectives
Objective 1: Determine the cold tolerance of the emerald ash borer parasitoids based on lab assays.
Objective 2: Predict expected mortality in locations where parasitoid overwintering potential is unknown.
Methods: Parasitoid Rearing Rearing regiments at EAB Biological Control Facility, Brighton, MI:
Temperature: Warm 18h 26.5
C: 6h 22.5
C, Cool 18h 20
C: 6h 15
C Photoperiod: Long 18h L: 6h D. Short 6h L: 18h D
O. agrili:
1. Diapause condtions (warm temperature / short photoperiod).
T. planipennisi: 1. Summer conditions (warm / long). 2. Fall conditions (cool / short).
S. agrili: 1. Summer conditions (warm / long). 2. 1 generation diapause (cool / short). 3. 2 generation diapause (1st generation warm / short, 2nd generation cool /
short).
Methods: Cold Tolerance Measures Lower Lethal Temperature
(LLTemp): mortality after instantaneous exposure from -15 to -35
C.
Supercooling Point (SCP): Temperature at which intracellular fluid freezes.
Lower Lethal Time (LLTime): 3 to 84 days at 0 to -15
C.
Mortality measured as discoloration 3 days after exposure or failure of adult emergence.
Thermocouple syringes and polystyrene cubes.
0
0.5
1
-40 -35 -30 -25 -20 -15 -10
Mor
talit
y
SEM
Temperature
C
Warm/short
1 gen. diapause
2 gen. diapause
S. agrili LLTemp
0
0.5
1
-40 -30 -20 -10 0
Pro
port
ion
Free
zing
Temperature
C
2 gen. diapause
1 gen. diapause
Warm/short
S. agrili Supercooling Points
Kuiper test: Warm/long vs. 1 gen. dia.:<0.0001 Warm/long vs. 2 gen. dia.:<0.0001 1 gen. vs 2 gen.:0.0931
0
0.5
1
-40 -35 -30 -25 -20 -15 -10
Cum
mul
ativ
e Pr
opor
tion
Temperature
C
LLTemp Mortality
Supercooling Points
S. agrili Freeze Tolerance
T. planipennisi LLTemp
0
0.5
1
-40 -35 -30 -25 -20 -15 -10
Mor
talit
y(fa
ilure
of p
upat
ion)
SEM
Temperature
C
Warm/short
0
0.5
1
-35 -30 -25 -20 -15 -10
Pro
port
ion
Free
zing
Temperature
C
Cool/short
Warm/Long
Kuiper test: Warm/short vs. cool/short.:<0.0001
T. planipennisi Supercooling Points
0
0.5
1
-40 -35 -30 -25 -20 -15 -10
Cum
mul
ativ
e Pr
opor
tion
Temperature
C
LLTemp Mortality
Supercooling Point
T. planipennisi Freeze Tolerance
0
0.5
1
-35 -30 -25 -20
Pro
port
ion
Free
zing
Temperature
C
T. planiepennisi
S. agrili
O. agrili
Kuiper test: T. planipennisi vs. S. agrili: 0.003 T. planipennisi vs. O. agrili: <0.001 S. agrili vs. O. agrili: <0.001
Cold-acclimated Supercooling Points
Climate Modeling
Model Choices:
• S. agrili cool/short 1st gen. diapause rearing LLTemp.
• T. planipennisi warm/long rearing LLTemp.
• Minimum annual air temperature data for 2002-2009 from weather stations (Midwest Regional Climate Center).
• Air temperature +1
C to account for under bark temps (Vermunt et al. 2012).
Predicted Mean S. agrili Cold Mortality 2002-2009
Predicted Mean T. planipennisi Cold Mortality 2002-2009
Lower Lethal Time
0
0.2
0.4
0.6
0.8
1
0 20 40 60 80 100Days of Exposure
LLTime: S. agrili Normal Rearing
0 -5
-10 -15
Temperature (°C)
Cum
m. P
erce
nt M
orta
lity
±SE
M
Cold Tolerance Conclusions
S. agrili more cold tolerant than T. planipennisi S. agrili appears freeze intolerant and T.
planipennisi primarily chill intolerant. O. agrili has the lowest supercooling point.
Length of time at warmer temperatures (0 to -15
C) can also be a significant source of
mortality.
Adult emergence measures for S. agrili ongoing.
Climate Modeling Conclusions • High mortality (>50%) in northern MN and
WI.
• Previous parasitoid recoveries in areas of low mortality.
• LLTime needs to be incorporated to model mortality in areas with warmer temperatures.
• Future research needed on minimum population levels for needed establishment.
Acknowledgements Funding support from USDA-APHIS and Minnesota
Legislative-Citizen Commission on Minnesota Resources.
Minnesota Department of Agriculture.
USDA Biological Control Facility, Brighton, MI.
References Bauer, L.S., Liu, H.P., 2007. Oobius agrili (Hymentoptera: Encyrtidae), a
solitary egg parasitoid of emerald ash borer from China. Lelito, Jonathan. USDA-APHIS EAB Rearing Facility, Brighton MI. Poland, T., and D. McCullough. 2006. Emerald ash borer: Invasion of
the urban forest and the threat to North America’ ash resource. J. For. 104: 118- 124
Vermunt, B., Cuddinton K., Sobek-Swant, S. Crosthwaite, J. 2012. Cold temperature and emerald ash borer: Modelling the minimum under-bark temperature of ash trees in Canada. Ecological Modelling 235-236: 19-26.
Ulyshen MD, Duan JJ, Bauer LS, Gould J, Taylor P, Bean D, Holko C, Van Driesche R. 2011. Field-cage methodology for evaluating climatic suitability for introduced wood-borer parasitoids: Preliminary results from the emerald ash borer system. Journal of Insect Science 11:141 available online: insectscience.org/11.141
top related