News and Reviews

Biological Control at National Entomology Society Meetings

The following is a continuation of brief summaries of some presentations made at the 1996 National Meeting of the Entomological Society of America in Kentucky.

1. Factors affecting mortality of the European corn borer in Illinois - M. Venditti, Univ. Illinois

The parasitoid Macrocentrus grandii was the most important mortality factor for both generations of ECB. Infection by the fungi Nosema pyrausta and Beauveria bassiana were low. Only 5% of the eggs were parasitized by Trichogramma.

2. Novel liquid release technique for delivering eggs of the green lacewing, Chrysoperla rufilabris - L. Wunderlich, Univ. Calif. - Davis

An intermittent spray nozzle was adapted to create this new liquid mechanical release technique for green lacewing egg application in crops. It does not affect hatching of the eggs or their adhesion on the crop. Eggs are held in suspension by gently bubbling air through the water in the tank, and the eggs can then be sprayed onto plants.

3. Autodissemination of entomopathogenic fungi into a population of Japanese beetles - J. Grundler, Missouri Dept. Agric.

An autodissemination trap was used to disperse the fungus Metarhizium anisopliae: an attractant lures in adult beetles, which then have to walk through a spore preparation to exit the trap. Over 40% of the beetles in the treated area were carrying the fungal spores, compared with only 6% in control areas. Population counts next year will give an indication of the effectiveness of such treatments in controlling the larval stage.

4. Effect of vegetable production systems on pest and beneficial arthropod populations - R. Hummel, North Carolina State Univ.

Pitfall trap data suggest that total arthropod activity is higher in plots with a living cover than those that are tilled or left weedy. The dominant predator in their plots was the thin-legged wolf spider, Pardosa sp.

5. Greenhouse experiments for control of western flower thrips using an entomopathogenic fungus, azadirachtin and a predatory mite - R. Lindquist, Ohio State Univ.

The fungus Paecilomyces fumosoroseus, neem, and the predatory mite Neoseiulus cucumeris were tried against western flower thrips. The best control was achieved with fungus sprays and granules on the potting mix surface. Other combinations with the fungus were good too, and neither the fungus nor neem harmed the predatory mites.

6. Microbial control: Past and present successes and future prospects - L. Lacey, USDA, Wapato, Washington

Gazing into the crystal ball: Future success in microbial control will be through integration with other natural enemies in IPM systems and fine-tuning of those microbial control agents we have in hand in addition to discovery of new isolates and organisms.

7. Are insect predators more active in diverse hedgerows? - J. Varchola, Univ. No. Iowa

Ground beetles are not more numerous in woody hedge habitats than in simple grass habitats (typical of Iowa corn fields), but there are differences in their activity in the adjacent field. Beetles appear to move from the hedges into fields more than from grasses (although the author suggests this could be an artifact of the sampling method).

8. Could natural populations of Coleomegilla maculata be manipulated to have a practical impact on Colorado potato beetle management in North Carolina potato fields? - B. Nault, North Carolina State Univ.

Asynchrony between natural populations of the twelvespotted lady beetle and first generation Colorado potato beetle reduces the possibility of manipulating lady beetle populations to provide any practical impact on potato beetle populations.

9. Inundative release strategies for biological control of Lygus hesperus by Anaphes iole in strawberries - S. Udayagiri, Univ. Calif. - Berkeley

Anaphes iole is an egg parasite of the tarnished plant bug that is now commercially available. Releases of 15,000 adult wasps/week/acre reduced plant bug populations about 50%, which is equivalent to chemical control success. However, this and other release rates and timing of releases that were tried were not economical. Research is continuing to address the factors limiting implementation.

10. Biological control of mites on apple with pyrethroid-resistant Typholodromus pyri from New Zealand - J. Hardman, Atlantic Food & Hort. Cent., Nova Scotia, Canada

Despite annual applications of cypermethrin (used to control leafrollers, but toxic to predatory mites) the New Zealand strain of the predatory mite T. pyri colonized trees and reached relatively high numbers. European red mite numbers dropped from 13/leaf to only 1/leaf after 3 years. Summer pruned shoots can be used to easily spread T. pyri to other trees.

11. Effective inundative biological control of whiteflies on greenhouse poinsettias - O. Minkenberg, Univ. Arizona

The wasp parasitoid Eretmocerus is able to suppress silverleaf whitefly populations on poinsettia in greenhouses, but much higher release rates (>7 female wasps/plant) are necessary to achieve effectiveness in the Southwest than in the Northeast (only 3 females/plant).

12. Biology of Nephaspis oculatus and its potential as a biocontrol agent of Bemisia argentifolii - T.-X. Liu, Univ. Florida

N. oculatus is a small black lady beetle, common in Florida, that appears to be a good candidate for biological control of silverleaf whitefly.

13. Efficacy of Beauveria bassiana for control of lygus bugs in alfalfa seed fields - T. Noma, Univ. Idaho

The fungus B. bassiana alone was not sufficient to control lygus bugs on small alfalfa plots. The impact on the bugs was minimal, although the fungus was more effective on adults than large nymphs.

These are only some of the many facets of biological control that were covered at the Entomology meetings.

EPA Registers Six New Biological Pesticides in First Quarter of FY97

EPA has registered six new biological pesticides in the first quarter of FY 1997, which ended Dec. 31, 1996. Four of the new materials are microbial pesticides, including three new Bacillus thuringiensis products. The following are brief descriptions of the new microbial pesticides.

Stine Microbial Products of Adel, Iowa was granted registration for Burkholderia cepacia isolate (trade name Blue Circle) as a fungicide for controlling damping-off disease on plant roots and seedling roots of vegetables, fruits, nuts, vine crops, spices, ornamentals, greenhouse crops, turfgrasses, flowers, bulbs and field crops. It may be applied through the irrigation system, drenching roots of seedlings or incorporating into seedbeds at planting.

Monsanto Co. of St. Louis, Mo. was granted final registration for Bacillus thuringiensis CryIA(b) delta-endotoxin and the genetic material necessary for its production in corn (trade name YieldGard), a plant-pesticide for controlling or suppressing the European corn borer, the Southwestern corn borer and the corn earworm. EPA has limited annual use to l00,000 acres in Southern states. In addition, the acreage may not exceed five percent of the corn planted in any county with more than l,000 acres of cotton. These limitations were imposed to mitigate the risk of developing resistance to Bt CryIA by the corn earworm, a pest of corn, cotton, and other Southern crops.

Ciba-Geigy Corp. of Greensboro, N.C. was granted registration for Bacillus thuringiensis kurstaki strain M-200 (trade name Able) for controlling lepidoperous (caterpillar) pests in tree fruits, terrestrial small fruits and vegetables, tree nuts, alfalfa, corn, cotton, soybeans, peanuts, herbs and spices and cranberries. It may be applied aerially or by ground equipment.

Ecogen Inc. of Longhorne, Pa. was granted registration for Bacillus thuringiensis kurstaki strain EG7826 (trade name Lepinox) for controlling lepidopterous (caterpillar) pests of numerous terrestrial food crops, ornamental plants, turf, nursery stock, shade trees and forests. It may be applied aerially or by ground equipment.

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