Biodiversity and structure of ground beetle assemblages (Coleoptera Carabidae) in Bt coro and its effects on non target insects

Abstract

During the years 1997-1998 an in-field evaluation was made of the
effects of transgenic corn on non-target arthropods and on soil fauna. Coleoptera
Carabidae, typical soil fauna, were studied and a comparison made of their
community structures and degree of specific biodiversity in transgenic and isogenic
corn crops. The taxa normally present on corn plants, particularly Aphididae and
Cicadellidae, Aranea and Coleoptera (Chrysomelidae, Coccinelidae,
Staphilinidae), and other insects living in dose contact with these or with the
European Corn Borer (Ostrinia nubilalis), such as Hymenoptera parasitoids and
Diptera Syrphidae, were considered as aerial fauna.
The statistica} analyses revealed no significant differences in the abundance of the
non-target entomofauna in isogenic corn and transgenic corn. The ground beetle
assemblages were quite similar, and any differences appeared to have no
correlation with the presence of Bt maize. The biodiversity of the Carabidae
communities was quite low for both types of crops and, on comparing the two
types of hybrid corn crops, no significant differences were found in any of the
indices analysed.