INSECTS ASSOCIATED WITH PURPLE LOOSESTRIFE, LYTHRUM SAUCARIA L., IN SOUTHERN MANITOBA.

Abstract

AbstractIn 1994 and 1995 insects were collected from several sites in southern Manitoba, where purple loosestrife, Lythrum salicaria L., is dominant. Collection techniques included the use of trap plants, sweep netting, vacuum sampling, and hand collecting. Insects from 38 families were collected and grouped into four general feeding guilds: herbivores, predators, omnivores, and fungivores. Herbivores that directly fed on L. salicaria included Galerucella nymphaeae Linné (Coleoptera: Chrysomelidae), Myzus lythri (Schrank) (Homoptera: Aphididae), Poecilocapsus lineatus (Fabricius) (Hemiptera: Miridae), Kleidocerys resedae (Panzer) (Hemiptera: Lygaeidae), Ametastegia glabrata (Fallén) (Hymenoptera: Tenthredinidae), Orgyia leucostigma (Smith) (Lepidoptera: Lymantriidae), Lophocampa maculata (Harris) (Lepidoptera: Lymantriidae), Spilosoma virginica (Fabricius) (Lepidoptera: Arctiidae), Simyra henrici (Grote) (Lepidoptera: Noctuidae), Dichomeris ligulella (Hübner) (Lepidoptera: Gelechiidae), Melanchrapicta (Harris) (Lepidoptera: Noctuidae), Hyles galli (Rottenburg) (Lepidoptera: Sphingidae), and Biston betularia cognataria (Gn) (Lepidoptera: Geometridae). These herbivores cannot severely limit the density of purple loosestrife in southern Manitoba and any interactions with the introduced agents should be minimal. The predatory stink bug, Apoecilus bracteatus Fitch (Hemiptera: Pentatomidae), was identified as a potentially important predator of the introduced biological control agents, Galerucella pusilla Duftschmidt and Galerucella calmariensis (L.) (Coleoptera: Chrysomelidae).