Sex pheromone of the larch caterpillar moth, Dendrolimus superans, from northeastern China

The larch caterpillar moth, Dendrolimus superans Butler (Lepidoptera: Lasiocampidae), is a serious pest in the northeastern part of China. In order to develop an effective method for monitoring D. superans, we began a project to identify the sex pheromone of D. superans and preliminary results were published in a note in 2001. Here we report complete laboratory and field results to support the identification. (Z,E)-5,7-Dodecadienal, (Z,E)-5,7-dodecadienol, (Z)-5-dodecenol, and (Z)-5-dodecenal (100:95:75:71) were identified by gas chromatography (GC) and coupled GC-mass spectrometry in extracts of pheromone glands of female D. superans. However, only (Z,E)-5,7-dodecadienal elicited strong responses from conspecific male antennae in coupled GC-electroantennography studies. Field tests with synthetic compounds indicated that baits containing (Z,E)-5,7-dodecadienal as a single component attracted male D. superans moths, whereas addition of one, two, or all three of the possible minor components did not increase the attractiveness of lures. (Z,E)-5,7-Dodecadienyl acetate, one of the pheromone components in sympatric Dendrolimus species, was antagonistic, but the analog (Z,E)-5,7-dodecadienyl propionate, another pheromone component in sympatric Dendrolimus species, was not. Since 2005, pheromone traps baited with (Z,E)-5,7-dodecadienal have been used effectively for monitoring populations of D. superans in various areas of northeastern China.