A comparison of insects pollinating two species of Cornus

Floral visitors to Flowering (Cornus florida L.) and Kousa (Cornus kousa (Buerger ex. Miq.) Hance) Dogwoods were both observed and captured during Spring 2008 to identify key arthropod species in the pollination guild for these trees common to Tennessee woodlands and landscapes. The floral structures of C. florida and C. kousa are similar, consisting of four white or red bracts surrounding an inflorescence comprised of 15-30 small flowers. Flowers of C. florida were open from April 11 to April 25 and yielded 118 specimens. The most common visitors were Hymenopterans in the Andrenidae (26%) and Halictidae (27%) families. The families Syrphidae, Scathophagidae, Cerambycidae, and Bombylidae were also well-represented visitors to C. florida. By contrast, C. kousa flowered later, from May 7 to May 27, and yielded 367 specimens. Visitors to C. kousa were primarily Scarab (40%) and Soldier (18%) beetles, Sarcophagid (13%) flies, and Halictid bees (8%). Other families of importance to pollination of C. kousa include Syrphidae, Miridae and Cerambycidae.