The Role of Nutrition in Susceptibility of Helicoverpa Zea Field Populations to Cry1Ac

Transgenic crops that produce insecticidal toxins are widely used to control herbivorous pests such as Helicoverpa zea.  A major threat to the use of transgenic crops is the development of resistant phenotypes by insect pests.  Most studies focus on the genetic factors responsible for resistant phenotypes, ignoring the effects of environmental factors such as nutrition.  In our study, we compared how macronutrient content and protein carbohydrate ratios within a diet can affect the susceptibility of field versus laboratory populations of H. zea to the Cry1Ac toxin widely used in Bt cotton. Understanding how nutrition can mediate the expression of susceptibility to Bt toxins in natural populations can allow us to develop more effective strategies for resistance management and control of this pest in the field.