Tritrophic choice experiments with Bt plants, the diamondback moth (Plutella xylostella) and the parasitoid Cotesia plutellae.
Authors: Schuler, T.H.; Potting, R.P.J.; Denholm, I.; Clark, S.J.;Clark, A.J.;Stewart, C.N.; Poppy, G.M.
Journal, Volume, Year: Transgenic Research, volume 12:351-361, 2003
A series of tests were conducted to examine the interaction of the parasitoid Cotesia plutellae with Bt and wildtype oilseed rape plants (Brassica napus) that had been damaged by either susceptible or resistant diamonback moths (Plutella xylostella). In wind tunnel experiments, C. plutellae did not distinguish between Bt and wildtype plants, but did prefer Bt plants that were damaged by Bt resistant P. xylostella. Authors state that population scale caged experiments with mixtures of Bt and wildtype plants demonstrate that C. plutellae is effective at controlling Bt-resistant larvae on either plant type.
Wind tunnel choice experiments are valuable and incorporate behavior, which is unusual. The parasitoid seems to seek out the active (in cases of Bt fields, Bt-resistant) larvae, which is important since it is unable to complete development in the intoxicated larvae.