Dimethylfuran-Lactone Pheromone from Males of Galerucella calmariensis and Galerucella pusilla

Male Galerucella calmariensis and Galerucella pusilla (Coleoptera:-Chrysomelidae) emit an aggregation pheromone while feeding on host-foliage. Isolation of the compound from collected volatiles was guided by-comparisons of gas chromatograms of extracts from males and females and by-gas chromatography-electroantennographic detection. The compound was-identified by a combination of spectrometric methods and microchemical tests-as the novel dimethylfuran lactone, 12,13-dimethyl-5,14-dioxabicyclo[9.2.1]--tetradeca-1(13),11-dien-4-one. The structure was confirmed by synthesis, and-the synthetic compound attracted males and females of both species in field-bioassays. These beetles were previously introduced into North America as-biological control agents for the invasive wetland weed, purple loosestrife-Lythrum salicaria, and the pheromone could become a tool for monitoring-populations. A new method is described for distinguishing the two species-based on the tibial spurs of the males.