Barriers to Hybridization between Diabrotica virgifera and D. longicornis barberi (Coleoptera: Chrysomelidae)

Abstract

Eggs from interspecific laboratory crosses between Diabrotica virgifera and D. longicornis barberi had a much lower percentage of hatch than eggs from conspecific pairings. No-choice mating tests over 24 hours resulted in greater than 70% conspecific insemination but no interspecific insemination. In an experiment giving males a choice only conspecific mating occurred. Some interspecific insemination occurred when beetles were confined together for periods of 11 days and 30 days. With D. virgifera, fecundity was enhanced by conspecific and interspecific insemination. Two barriers to hybridization were detected; one involved mating behavior and the other was a postinsemination barrier which reduced egg viability.