Scientists Study Tritrophic Interactions Among Bt Maize

When Bt crops started to be grown in the fields, a new form of host-plant resistance has been introduced in agroecosystems. The interaction of Bt crops with natural enemies like insect pathogens found in the soil could be used to study the transfer of energy in three different trophic levels.

Iowa State University scientist J. L. Petzold-Maxwell and colleagues used two soil-borne pathogens (a fungi and a nematode) to determine how they might interact with Bt maize (event 59122) to influence the survival and development of western corn rootworm (Diabrotica virgifera virgifera).

The research team conducted experiments in a greenhouse and in a growth chamber. Results showed that the community of pathogens significantly increased mortality of the rootworm, while Bt maize increased larval developmental time and mortality. Both the pathogens and Bt maize acted in independent and additive manner, increasing the mortality of the rootworm. Therefore, this suggests that soil-borne pathogens may complement host-plant resistance in Bt crops.

Read the abstract at http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7348.2011.00515.x/abstract.