Effect of a seed-mix deployment of Cry3A transgenic and nontransgenic potato on the abundance of Lebia grandis (Coleoptera:Carabidae) and Coleomegilla maculata (Coleoptera: Coccinellidae)
Authors: Riddick, E.W., Dively, G., Barbosa, P.
Journal, Volume, Year: Annals of the Entomological Society of America, volume 91(5):647-653, 1998
Examined abundance of Coleomegilla maculata and Lebia grandis (a carabid specialist on Colorado potato beetle) in mixed fields of transgenic (Cry3A) and nontransgenic potato. CPB populations were established through infestation. Applied esfenvalerate to the non-transgenic field and dimethoate to all of the fields. Sweep samples were used to collect C. mac and pitfall traps for L. grandis. Fields were 100, 70 and 30% transgenic. L. grandis were less abundant in transgenic and mixed fields. C. mac numbers were not significantly different in any treatment. L. grandis numbers were significantly correlated (but low) with CPB numbers.
L. grandis may move out of fields with transgenics because of a lack of available prey. A tritrophic test for an effect of Bt fed prey would be interesting.