Catching Helicoverpa survivors on Bollgard II with green lacewing

Abstract

Widespread adoption of Bt (Bollgard II) cotton has led to a dramatic reduction in insecticide use in Australian cotton. CSIRO research has shown that Bt cotton does not affect the survival of most beneficial species, and their numbers are higher in comparison with conventional cotton because of the reduction in insecticides. But can we be sure these beneficials are still doing the same job in controlling pests in Bt cotton? Do we know their behavioural patterns and prey consumption rates are similar in Bt compared to conventional cotton? Some preliminary experiments by PhD student Habibullah Bahar (Figure 1) and his supervisors at the University of New England indicate that at least one beneficial, the green lacewing 'Mallada signata', is still doing the job in Bt cotton.