We evaluated the effect of weight, collection site, and age upon mating behaviors of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) with multivariate analysis. Our laboratory study of D. virgifera revealed that female weight was positively associated with the likelihood of mating, although female weight was not associated with females' receptivity to aedeagus insertion. Furthermore, the relationship between male and female weight on mating was investigated at two field locations in Indiana, and evidence of nonrandom mating was found. The implications of these results for pest management are discussed, with particular focus upon using this information for the construction of robust viable resistance management systems in Bacillus thuringiensis corn, Zea mays L.