Elasmus albizziae (Burks) and Parania geniculata (Holmgren) are parasitoids of the honeylocust pest mimosa webworm, Homadaula anisocentra Meyrick. Populations of the pest and these parasitoids were observed in the West Lafayette, IN campus of Purdue University between 1998 and 2001. Defoliation by first and second generations of H. anisocentra were quantified using visual estimates of the percent browning of the trees' canopy. First-generation parasitism of H. anisocentra was determined from pupae collected from webs. Second-generation parasitism of the overwintering population was measured from artificial pupation sites fashioned from corrugated cardboard. Yellow sticky traps were also used to monitor seasonal abundances of parasitoids in the field. Percent browning ranged from 10.9-13.7% in the first generation and 24.3-32.5% in the second generation. Combined percent parasitism of pupae ranged from 9-28%. On average, 70% of all attacks were made by E. albizziae and 30% by P. geniculata. Yellow sticky traps measured seasonal abundances for E. albizziae. E. albizziae emerged at 1000 DD50 (cumulative degree-days) and peaked near 2700 DD50. These data reveal that both parasitoids contribute to pest mortality, and should be considered when making decisions in an IPM program for honeylocusts.
Species 1: Lepidoptera Plutellidae Homadaula anisocentra (mimosa webworm)
Species 2: Hymenoptera Elasmidae Elasmus albizziae
Species 3: Hymenoptera Ichneumonidae Parania geniculata
Keywords: Honeylocust, urban forestry
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA