Palaearctic seed beetle Bruchus affinis (Coleoptera, Chrysomelidae, Bruchinae) new to North America, arrival, distribution, and autecology

Abstract

First North American records are presented for Bruchus affinis Frölich, 1799 (Coleoptera, Chrysomelidae, Bruchinae), as confirmed by morphology from multiple sites in Canada: British Columbia, Ontario, and Québec. Diagnostic information is presented for B. affinis in North America. This insect is expected to reduce plant reproductive output in infested Lathyrus latifolius L., Lathyrus sylvestris L., and other potential Lathyrus (Fabaceae) hosts. Impacts on broad bean (Vicia faba L.) production are expected to be small. Potential reproductive impact on native North American Lathyrus species remains unknown. The United States of America and Canada are now known to be home to 69–79 species of adventive Chrysomelidae including 16–18 Bruchinae. We have found two dead, teneral B. affinis individuals inside Lathyrus seeds imported from Europe, and we hypothesise that this species was introduced to Canada from Europe via seeds for planting sometime before 2007. At our study sites, Lathyrus flowering began in mid June followed by oviposition in late June with first adults emerging in late August, requiring about 60 days from egg to adult stage. Dinarmus basalis (Rodani, 1877) (Hymenoptera, Pteromalidae) was newly recorded as parasitoid of Bruchus affinis in Canada, and caused about 10% mortality in B. affinis at our sites.