Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2000
Publication Date: 7/1/2000
Citation: Horton, D.R., Hinojosa, T.L., Lewis, T.M. 2000. Mating preference, mating propensity, and reproductive traits in Anthocoris nemoralis (Fabricius) (Heteroptera: Anthocoridae): a comparison of California and United Kingdom populations. Annals of the Entomological Society of America. 93:663-672. Interpretive Summary: The predatory bug Anthocoris nemoralis is an important biological control agent in pear and apple orchards of Europe. The species has successfully colonized parts of North America following accidental or intentional introductions, and it was unclear whether populations on the two continents differ in aspects of reproductive biology. In this study, we compared two populations of insects in several aspects of reproductive biology: a population from the San Francisco area and a population from southern England. In choice tests, insects demonstrated no preferences for mating with insects from the same source population. The majority of mated females matured their eggs, irrespective of whether the male was from the same population or from the other population. Females from both populations required only 3 days following mating to begin laying eggs. Insects from both populations were capable of mating within 1 or 2 days following the adult molt. Several characteristics of A. nemoralis, including its generalized feeding habits, rapid maturation of adults, short period between mating and egglaying, and apparent low levels of mating choosiness may help explain why this species has so successfully colonized new geographic areas, including several areas in North America.
Technical Abstract: Anthocoris nemoralis is a common predator native to Europe that has established in North America. We compared mating activities and life history traits between a European and North American population of A. nemoralis. In no-choice and choice assays, insects showed no preferences for mating with insects from the same source. Assays showed that insects from the two populations differed in mating propensities: UK females were less likely to be mated during a 30 min assay than females from California; and, California males were less likely to be mated than males from the UK. A majority of mated females matured ovaries from all crosses. Copulation duration was 3.1 min shorter in pairings involving California males than matings involving UK males. Long-duration matings often failed to prompt ovarian development. The preoviposition period averaged 3 d for females from both populations. Insects of both sexes were able to mate within 24-48 h of eclosion. Young males copulated longer and were less likely to prompt ovarian development in the female than old males. Several traits of A. nemoralis, including its feeding habits, rapid maturation, short preoviposition period, and low levels of mating discrimination may help explain why it has successfully colonized new geographic areas.