Influence of reproductive ecology on feasibility of mass trapping Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae).
Abstract
Laboratory and field experiments were carried out in Ontario, Canada, in 1985-86 on Diabrotica virgifera virgifera. Most males emerged from pupae at the same time as females. In the field, the majority of females mated within a day of emergence. When supplied with an excess of virgin females in field cages, large males usually initiated mating at an earlier age and mated more often than small ones. Neither longevity nor the mass of spermatophores were related to male size, so small males, that sometimes mated twice daily, transferred a greater proportion of their resources at each mating. Males supplied with a poor diet died sooner, produced a smaller mass of spermatophores and mated less often than those provided with a better diet. Spermatophore mass production was correlated with age, especially during the first 10 days after emergence. The reproductive potential of populations of D. virgifera virgifera exceeded the number of available virgin females in corn [maize] fields, and so intraspecific competition between males is expected to be great. It is concluded that tactics relying on male removal have little potential for control of this species.