Female sex pheromone of a nettle caterpillar, Monema flavescens, in China

Monema flavescens Walker (Lepidoptera: Limacodidae) is a multivoltine, generalist moth whose larvae cause serious damage to many types of trees. Pheromone lures prepared according to a study of a Japanese population were found to be ineffective at attracting M. flavescens nettle caterpillars in China, and some studies have shown intraspecific geographical differences in the composition of sex pheromones. We therefore reexamined the sex pheromone composition of M. flavescens in a Chinese population. In this study, the electroantennographically (EAG) active compounds in an extract from Chinese virgin females of M. flavescens were identified as (E)-8-decen-1-ol (E8-10:OH), (Z)-7,9-decadien-1-ol (Z7,9-10:OH), (Z)-9,11-dodecadien-1-ol (Z9,11-12:OH), and (Z)-9,11-dodecadienal (Z9,11-12:Ald) via coupled gas chromatographic-electroantennographic detection (GC-EAD) and coupled GC-mass spectrometry (MS). Pheromone dimorphism might occur in this species, as this mixture of compounds in Chinese females was different from that of E8-10:OH and E7,9-10:OH extracted from Japanese females in previous research. In wind tunnel and field tests, the males were significantly attracted to a blend of the pheromone components E8-10:OH, Z7,9-10:OH, and Z9,11-12:OH in a 100:5:4 ratio. The addition of Z9,11-12:Ald did not change the male response. The optimized three-component lure blend may provide a useful tool for monitoring and controlling Chinese populations of M. flavescens.