Survey of stink bug (Heteroptera: Pentatomidae)

egg parasitoids in wheat, soybean and vegetable crops in

Southeast Virginia

Amanda L. Koppel

Dr. Ames Herbert, Tidewater AREC

Dr. Tom Kuhar, Eastern Shore AREC

12/11/06

Outline

• Introduction– About stink bugs– Stink bugs in SE Virginia– Control

• Methodology– Field survey– Sentinel eggs

• Results– Rates of parasitism– Egg parasitoid species complex

• Discussion & Further Study

Stink Bugs (Heteroptera: Pentatomidae)

• Phytophagous and predatory species

• Pentatominae include spp. of economic importance

• Feed with stylets• Damage to plants

– Cosmetic– Growth and development– Yield and quality

Stink Bug Economic Damage of Selected US Commodities

(McPherson & McPherson, 2000)

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

(1997)

Stink Bugs in SE Virginia

• Treatment:– Economic thresholds– Pyrethroids are insecticide of choice– Stink bugs may not be seen as a threat!

• Monitoring– Blacklights– Pyramid traps– Field survey

• Most common species?

Brown stink bug

(Euschistus servus)

Green stink bug

(Acrosternum

hilare)

Biological Control of Stink Bugs

• Egg parasitoids are most common• Natural enemy surveys

– Carolinas (Jones et al. 1996)

– Louisiana (Orr et al. 1986)

– Kentucky (Yeargan 1979)

– Florida (Temerak & Whitcomb 1984)

– California (Ehler 2002)

– Brazil (Correa-Ferreira & Moscardi 1995)

Virginia Stink Bug NE Survey (2005-06 field seasons)

• Objectives– To determine if there are stink bug

natural enemies (specifically, egg parasitoids) in SE VA

– Determine rates of parasitism– Determine parasitoid species composition

Field Eggs

• Swept and visually inspected field and vegetable crops for stink bug egg masses

• Masses returned to the lab• Noted

– Parasitoids– Stink bug nymphs– No hatch

Sentinel Eggs

• From lab colony• Placed in the field

for a week– Pinned to the

underside of leaves

• Collected and returned to quarantine

• Observed as field eggs

Surveyed Eggs

Field eggs Sentinel eggsEuschistus servus 570 2336Acrosternum hilare 546 n/a

Podisus maculiventrus 15 230Murgantia histrionica 8782 n/a

Total: 12, 479 eggs

Percent Parasitism

E. servus eggs

40%

22%

38% # parasitized

# no hatch

# SB nymph hatch

(cont.)

A. hilare eggs

20%

35%

45%# parasitized

# no hatch

# SB nymph hatch

(cont.)

P. maculiventrus eggs

12%

41%

47%

# parasitized

# no hatch

# SB nymph hatch

(cont.)

M. histrionica eggs10%

38%52%

# parasitized

# no hatch

# SB nymph hatch

Parasitoid IDs

• All Hymenoptera• Mymaridae• Scelionidae-- Telenomus and Trissolcus• Used keys by N.F. Johnson, Ohio State

E. servus-- Telenomus podisi

M. histrionica-- Trissolcus basalis & a Mymarid

A. hilare

Not pictured: Trissolcus euschisti

Trissolcus eddesae

Trissolcus basalis

Not So Generalist?

• Egg parasitoids tended to stick to certain host species

• Some crossover• Stink bug host crop was irrelevant

Significance

• Great deal of heretofore unknown biological control in VA– Meaning to farmers– Effect of chemical sprays on

parasitoid oviposition• Parasitization in both 1st and 2nd

generations• Choice testing of Telenomus podisi

THANK YOU!!

• Faculty:– Dr. Douglas Pfeiffer– Dr. Scott Salom– Dr. Kim Hoelmer, USDA-ARS-BIIR

• Graduate Students– Kathy Kamminga, SB Survey Data

Questions?