Effect of different temperatures on the development and fitness of western corn rootworm.

Abstract

Summary The objective of this study was to obtain data that could be used to develop a model for forecasting the occurrence of Diabrotica virgifera virgifera. The model currently available is mainly based on results from American studies using non-diapausing beetles, but the biological performance (fitness and mobility) of American nondiapausing beetles and those of European origin could differ, which would affect the accuracy of this model when used for forecasting in Europe. Thus, it is important to know whether the biological performance of D. virgifera virgifera of European origin differ from that of non-diapausing American beetles. The following aspects of the effect of temperature on the biology of D. virgifera virgifera occurring in Europe were studied and compared with those of a non-diapausing strain from the US: - pre-diapause development of eggs, - post-diapause development of eggs, - effect of different temperatures and densities on the development of larvae. The results indicate that the American data based on studies of non-diapausing strains of D. virgifera virgifera are of only limited use for forecasting the occurrence of this pest in Europe. In particular, the results obtained for the development of eggs, larvae and adults provide information about this species’ biology that could be used to increase our understanding of the population dynamics of this pest in Europe.