Sex pheromone of the blue-striped nettle grub moth Parasa lepida (Cramer) (Lepidoptera: Limacodidae): Identification and field attraction

Abstract

An EAG-active compound in the extract of virgin females of the limacodid, Parasa lepida (Cramer) was identified as (Z)-7,9-decadien-1-ol (Z7,9-10:OH). This compound was observed to attract conspecific males in the field. When 1 mg of Z7,9-10:OH was applied to a rubber septum and used as bait in sticky traps, its attraction was equivalent to that of two 2- to 5-d-old virgin females. GC-EAD analyses suggested weak EAG responses, but the most likely candidate compounds, (Z)-7-decen-1-ol and 9-decen-1-ol, exhibited neither synergistic nor inhibitory effects when either or both were blended with Z7,9-10:OH. Z7,9-10:OH was thus considered as a sex pheromone component of this species. However, the attractiveness of the synthetic sex pheromone declined rapidly over a 12-d exposure period in the field. This decline was likely attributed to a loss of the Z7,9-10:OH which has a low molecular weight (154) and is highly volatile.