Vegetable Crops

Corn Earworm Control on Sweet Corn With BT and Anagrapha falcifera NPV

A recently discovered multiple nucleopolyherovirus of the celery looper (Anagrapha falcifera), called AfMNPV, has a lot of potential as a microbial insecticide because of its relatively broad host range among caterpillars. AfMNPV is more virulent against corn earworm than the commercially-produced Heliothis nucleopolyhedrovirus, and offers another possibility for control of corn earworm on sweet corn.

This virus was compared in field tests with 2 subspecies of Bacillus thuringiensis (Bt) for controlling corn earworm on corn ears. All three pathogens significantly reduced the percentage of ears damaged and increased the number of marketable ears (to 80%). AfMNPV was as good or better than Bt for protecting the corn ear. However, these tests were done with artificial infestations of earworms; at high natural infestation levels control may not be satisfactory. Further investigations are necessary to determine the efficacy of AfMNPV on higher population levels.

Source:

Pingel, R. L. and L. C. Lewis. 1997. Field application of Bacillus thuringiensis and Anagrapha falcifera multiple nucleopolyhedrovirus against the corn earworm, (Lepidoptera: Noctuidae). J. Econ. Entomol. 90(5): 1195-1199.

Parasite for Asparagus Aphid

Natural enemies of asparagus aphid reportedly provide sufficient control in asparagus fields in the eastern U.S., but control in western states has been inadequate or sporadic. The parasite Trioxys brevicornis was imported from then-Czechoslovakia and released in 1989 in California to help control the European asparagus aphid, which had been invading asparagus throughout the west.

Over 68,000 wasps were released over two years at several sites. T. brevicornis became established and is enhancing the natural complement of aphid parasitoids, including Diaeretiella rapae, Aphidius colemani, and Aphelinus sp. and predators such as lady beetles, green lacewings, brown lacewings, and syrphid flies. Additional wasp releases were planned for other areas of California.

Source:

Daane, K. M., G. Y. Yokota, R. F. Gill, L. E. Caltagirone, K. S. Hagen, D. Gonzalez, P. Stary, and W. E. Chaney. 1992. Imported parasite may help control European asparagus aphid. California Agriculture 46(6): 12-14.


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