Copulation and Its Duration Affects Female Weight, Oviposition, Hatching Patterns, and Ovarian Development in the Western Corn Rootworm (Coleoptera: Chrysomelidae)

Abstract

To understand the relationship between copulation and ovarian development in the western com rootworm, Diabrotica virgifera virgifera LeConte, newly emerged virgin beetles were used to establish female groups of various copulatory durations. The results demonstrate that a mating of ≥1 h stimulates an increase in weight, egg-laying, and ovarian development. This stimulation in females mated for 1 h (none contained sperm in the spermatheca at the time of dissection) was transitory and lasted 1-2 wk. Females that mated for 2 h (contained sperm in the spermatheca at the time of dissection) were indistinguishable in weight, egg-laying, and ovarian development from females mated until natural completion; they were stimulated to a sustained mature ovarian state and were capable of laying eggs for at least 4-5 wk after mating. Unmated females of similar ages underwent limited ovarian development and rarely laid eggs.