News and Reviews

Biological Control at National Entomology Society Meetings

The following is a continuation of brief summaries of some presentations made at the 1997 National Meeting of the Entomological Society of America in Nashville (see previous issue).

1. Autodissemination of entomopathogenic fungi: A tool for biological control of the diamondback moth - J. Pell, IACR, Rothamsted, England

Work done in Malaysia and Africa has shown that fungal pathogens of diamondback moth, such as Beauveria bassiana and Zoophthora radicans, can effectively be spread using specialized traps. Male moths are lured into traps in response to synthetic sex pheromone. As they leave the trap they get contaminated with a lethal dose of the fungus. When they disperse back to the crop they disseminate spores to susceptible larvae and establish new infections. Transmission of Z. radicans is low (10-15%), but of B. bassiana to other adults (93-100%) and larvae (70%) is high.

2. Parasitoids found in on-farm stored shelled corn in Kentucky - B. Price, Kentucky State Univ.

Nine species of parasitoids were identified from samples taken in western Kentucky. Anisopteromalus calandrae was the most common one. Several species are successful in controlling stored grain pests and their use should be more widely adopted.

3. Field assessments of Beauveria bassiana for the biological control of aphids, whiteflies, and thrips - S. Thompson, Texas A&M Univ.

Commercial formulations of B. bassiana were tested against aphids and thrips on chrysanthemum and against western flower thrips on tomato in greenhouses. Liquid formulations were better than dry. A trial comparing the fungus with conventional insecticides for control of greenhouse whitefly on tomato had to be terminated because whitefly populations got too high. Tomato plant compounds may have a negative impact on the fungus.

4. Control of western flower thrips and greenhouse whiteflies with Beauveria bassiana and Conserve - S. Gill, Univ. of Maryland

Conserve, a spinosad insecticide, performed the best against western flower thrips on chrysanthemum. Two formulations of B. bassiana (BotaniGard and Naturalis) also gave good control when thrips populations were low. BotaniGard also gave good control of greenhouse whitefly on the aquatic plant parrot's feather.

5. The effect of apple cultivar on the establishment and population dynamics of Typhlodromus pyri - A. Roda, Cornell Univ., Ithaca, NY

T. pyri from Red Delicious apple trees produced twice as many eggs as mites from McIntosh trees, but populations were not any higher. T. pyri can tolerate lower humidity than Amblyseius fallacis, which may be why there are more T. pyri in early spring when the canopy is open.

6. Potential of Metarhizium anisopliae and Beauveria bassiana isolates for control of Culex quinquefasiatus - R. Pereira, Univ. of Tennessee

Initial results from aquarium experiments suggest M. anisopliae isolate 1037 can be used in a mosquito control program with weekly applications, alone or in combination with Bacillus sphaericus. This isolate caused >90% mortality; no other strain or B. bassiana was above 20%.

7. Migration of ground beetles between corn fields and woody hedges - J. Varchola, Univ. Northern Iowa

Ground beetles tend to move from field borders into corn fields after canopy closure. They show a seasonal preference for hedgerows or grass borders when corn field conditions are unfavorable (pre- and post-season).

8. Wandering spiders in soybean fields and adjacent hedgerows, and the influence of edge permeability on their movements - A. Cady, Miami Univ., Oxford, Ohio

Grassy field edges may be great for harboring spiders, but the spiders don't move into soybean fields very well to provide pest control.

9. Biology and ecology of the spider Clubiona abbotii, a predator of lepidopteran eggs - K. Yeargan, Univ. Kentucky

This nocturnal spider was the most commonly observed spider feeding on corn earworm eggs in soybean fields. Adults are good at searching plants for eggs and will eat 15-20 eggs a day. Each spider consumes about 440 eggs during its development to an adult.

10. Biological control of oblique-banded leafroller by inundative releases of Trichogramma minutum in a commercial blueberry field - R. McGregor, Cropconsult, Ltd., Vancouver, B.C.

Releases of T. minutum resulted in successful parasitism of leafroller eggs. The dispersal of adult wasps was limited to about 15m from the release point, so multiple release sites per field would be necessary.

11. Individual and combined effects of lycosid spiders and carabid beetles on cucurbit pests and productivity - W. Snyder, Univ. Kentucky

Wolf spiders increased the productivity of cucumbers in spring plantings by preying on striped cucumber beetles, but ground beetles had no impact in these spring plantings. In summer plantings, the beetles increased squash productivity by reducing squash bug, but the spiders preyed on other natural enemies, resulting in more squash bugs.

12. Biological control of leafrollers in Washington apples: Future prospects with soft pesticide programs and habitat manipulation - B. Pfannenstiel, Wash. State Univ.

An alfalfa ground cover provided alternate host leafrollers for parasitiods that may be limited in apple orchards if such alternate hosts are not available.

13. Synchrony between the tarnished plant bug and two exotic braconid parasitoids - S. Lachance, Univ. Guelph, Ontario, Canada

Peristenus digoneutis and P. stygicus are promising biocontrol agents for tarnished plant bug in Canada, but neither parasite emerges early enough in the spring to provide control.

14. Paecilomyces fumosoroseus, convergent lady beetles and the Russian wheat aphid: Potential interactions - J. Pell, IACR, Rothamsted, England

Although lady beetles never fed on fungus-infected aphids, individuals foraging in close proximity to sporulating aphid cadavers became contaminated with conidia. They were then able to passively vector the fungus to 53% of healthy aphids, but up to 22% of the beetles themselves also became infected and died.

 

Publications on Gypsy Moth Natural Enemies

Here are just a few of many publications on gypsy moth and its natural enemies.

Calosoma sycophanta: A Natural Enemy of Gyspy Moth Larvae and Pupae by Molly Mott and Deborah McCullough, Michigan State University Extension Bulletin E-2622 (1997). Other MSU Extension Bulletins include E-2604, Entomophaga maimaiga: A Natural Enemy of Gyspy Moth (the basis for the Know Your Friends article in MBCN Vol. III, No. 8) and E-2421, Using Bt to Control Gyspy Moth.

The Gypsy Moth Nucleopolyhedrosis Virus Product, by Richard Reardon and John Podgwaite, USDA Forest Service, Northeastern Area AIPM (1992).

The Gyspy Moth and Its Natural Enemies, USDA-FS Agriculture Information Bulletin No. 381 (1975). An old publication (so some scientific names have changed and more recent findings are absent), but with nice color drawings and good basic information. Mortality factors are categorized by the gyspy moth stages they affect. Single copies are available from the MBCN Editor, but the supply is very limited.


Return to Contents Menu Vol. V  No. 3


Go To Index