SEX-PHEROMONES OF THYSANOPLUSIA-INTERMIXTA AND T-ORICHALCEA - IDENTIFICATION AND FIELD-TESTS

Thysanoplusia intermixta, which inhabits the temperate zone in Japan, is a defoliator of plants in the family Compositae, Apiaceae, and othe rs. By CC-MS analysis, (Z)-7-dodecenyl acetate, (Z)-7-dodecen-1-ol, (5 E, 7Z)-5,7-dodecadienyl acetate and (5E,7Z)-5,7-dodecadien-1-ol were i dentified from a pheromone gland extract of the virgin females in a ra tio of 18:3:100: 13. A lure baited only with the major diene acetate c ould attract male moths of T. intermixta in the field. Other minor com ponents had a synergistic effect on the attraction of the diene acetat e. The same four components were included in a very different ratio of 100:6:11:1 in the gland extract of Thysanoplusia orichalcea, a closel y related subtropical species. The monoene and diene acetates are esse ntial for field attraction, and a 100:11 mixture is an optimum lure fo r T. orichalcea males. However, this mixture, including the diene acet ate as a minor component, captured very few T intermixta males, sugges ting the possibility that these two Thysanoplusia species are reproduc tively isolated from each other by pheromonal communication.