Great Diversity of Insect Floral Associates May Partially Explain Ecological Success of Poison Ivy (\u3ci\u3eToxicodendron Radicans\u3c/i\u3e Subsp. \u3ci\u3eNegundo\u3c/i\u3e [Greene] Gillis, Anacardiaceae)

Abstract

Little is known about insect floral associates of poison ivy (Toxicodendron radicans, Anacardiaceae), despite the species’ ubiquity and importance in nature and society. Poison ivy’s pollination syndrome and results from prior studies suggest that the plant is not specialized for any particular pollinator type; however, a systematic survey exploring this hypothesis has been lacking. For this study, insect floral associates of Toxicodendron radicans subsp. negundo from a central Iowa site were observed during the flowering season of 2005. Thirty- seven distinct insect floral associates were observed: 8 coleopterans (beetles), 7 dipterans (flies), 2 hemipterans (true bugs), 19 hymenopterans (ants, bees, wasps), and 1 lepidopteran (butterfly). Hymenopterans appeared to be the most important contributors to poison ivy pollination on a per species basis; however, coleopterans and dipterans were also frequent associates. Poison ivy’s ability to utilize a diverse assemblage of insect pollinators may partially explain its ecological success in varied habitats