Antennae of Cryptorhynchus lapathi (Coleoptera: Curculionidae) detect two pheromone components of coniferophagous bark beetles in the stems of Salix sitchensis and Salix scouleriana (Salicaceae)

Abstract

Several scolytid beetles (Coleoptera: Scolytidae) produce conophthorin, (E)-7-methyl-1,6-dioxaspiro[4.5]decane, and use it as an aggregation or antiaggregation pheromone or competition-mediating synomone (Francke et al. 1979; Kohnle et al. 1992; Birgersson et al. 1995; Pierce et al. 1995; de Groot et al. 1998; Dallara et al. 2000; Rappaport et al. 2000). Predators or associates of these beetles may use conophthorin as a host- or habitat-finding kairomone (Kohnle et al. 1992). Other conifer-infesting scolytid and predator species use chalcogran, 2-ethyl-1,6-dioxaspiro[4.4]nonane, a semiochemical with functions similar to those of conophthorin (Francke et al. 1977; Heuer and Vité 1984; Baader 1989; Byers 1993; Byers et al. 1989, 2000).