Biotech Updates

Tri-trophic Study Show that Bt Crops are Not Toxic to Insect Predator, Assassin Bug

December 3, 2014

Bt crops, such as maize and cotton, are subjected to environmental risk assessments for non-target enemies, including natural enemies that suppress the populations of the pests. Cornell University scientists H.H. Su and colleagues used Bt resistant fall armyworm (Spodoptera frugiperda) and cabbage looper (Trichoplusia ni) as prey for assassin bug (Zelus renardii), a common predator in maize and cotton fields. Several fitness parameters of assassin bug were assessed when it fed on resistant fall armyworm that fed on Bt maize or resistant cabbage looper that fed on Bt cotton. 

Results showed that there were no significant differences in the survival rate, nymphal duration, adult weight, adult longevity, and female fecundity of assassin bug fed with Bt resistant prey larvae reared on Bt or non-Bt crops. Antibody tests showed that Bt proteins were present at the highest levels in the Bt plants, at lower levels in the prey and at the lowest levels in the predator. Based on the findings, Bt proteins do not affect the vital fitness parameters in assassin bug. 

Read the abstract at