Identification and field evaluation of sex pheromones in two hawk moths Deilephila elpenor lewisii and Theretra oldenlandiae oldenlandiae (Lepidoptera: Sphingidae)

Abstract

The sex pheromones of two species of hawk moth, Deilephila elpenor lewisii (Butler) and Theretra oldenlandiae oldenlandiae (Fabricius), were analyzed using gas chromatography–electroantennographic detection (GC–EAD) and GC–mass spectrometry (GC–MS). Two and three EAD-active components were found in D. elpenor lewisii and T. oldenlandiae oldenlandiae, respectively. GC–MS analyses using authentic compounds and extracts derivatized by dimethyl disulfide and 4-methyl-1,2,4-triazoline-3,5-dione identified the two components in D. elpenor lewisii as (E)-11-hexadecenal (E11–16:Ald) and (10E,12E)-10,12-hexadecadienal (E10,E12–16:Ald), and the three in T. oldenlandiae oldenlandiae as E11–16:Ald, E10,E12–16:Ald, and (10E,12Z)-10,12-hexadecadienal (E10,Z12–16:Ald). In field-trap tests, no males of either species were attracted to any single components. Male moths of D. elpenor lewisii were specifically attracted to a binary blend of E11–16:Ald and E10,E12–16:Ald at a ratio of 85:15, whereas males of T. oldenlandiae oldenlandiae were attracted to a ternary blend of E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald at a ratio of 30:40:30. We therefore conclude that the sex pheromone of D. elpenor lewisii is a mixture of E11–16:Ald and E10,E12–16:Ald and that of T. oldenlandiae oldenlandiae is E11–16:Ald, E10,Z12–16:Ald and E10,E12–16:Ald.