Date of Award

1980

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Entomology

Abstract

An enzyme linked immunosorbent assay (ELISA) for detection of either Nezara viridula (L.) egg or nymphal protein in the gut of potential predators was developed. Through the use of molecular gel filtration species specific antigens were obtained from N. viridula eggs and nymphs. The ELISA developed for eggs could detect 7.6 ng of egg protein while the nymphal ELISA could detect 122 ng of the selected nymphal protein. There were 27 species of insects and spiders representing 6 orders and 15 families, tested for both egg and nymphal predation over 2 growing seasons (1977 and 1978). There were 1886 individuals tested for egg predation and 1983 tested for nymphal predation. The most important predator species were determined by a combination of their population density and the results of the ELISA. A complex consisting of 8 species plus Coccinellidae larvae as a group accounted for 91.4% of the egg predation over the entire 1978 growing season. These species were Geocoris punctipes (Say), Orius insidiosus (Say), Cycloneda sanguinea (L.), Coleomegilla maculata lengi Timberlake, Podisus maculiventris (Say), Solenopsis invicta Buren, Reduviolus roseipennis (Reuter), and Lebia analis Dejean. Nymphal predation was not as extensive as egg predation. A combination of predators consisting of a complex of 8 species plus the Coccinellidae larvae accounted for 95.4% of the entire season's predation. The predators included were Oxyopes salticus Hentz, G. punctipes, P. maculiventris, C. sanguinea, C. m. lengi, R. roseipennis, Phidippus audax (Hentz), and Neoscona arabesca (Walckenaer). No one species could be considered a key predator of either eggs of nymphs. Predation had to be viewed in the context of a complex. The complex was shown not to be static but dynamic according to the time of year and species present in the agroecosystem.

Pages

97

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