Blackheaded fireworm: Laboratory and field studies of its sex pheromone

Abstract

Electroantennogram (EAG) responses of maleRhopobota naevana (Hübner), the blackheaded fireworm, to all of the monoene straightchain 12- and 14-carbon alcohols and acetates implicated (Z)-11-tetradecenl-1-ol (Z11-14∶OH) and its acetate (Z11-14∶Ac) as sex pheromone components.Z11-14∶Ac produced the strongest EAG response of all compounds tested. Gas chromatography-mass spectrometry (GC-MS) analysis of extract of female sex pheromone glands (SPG) confirmed the presence ofZ11-14∶OH (125 pg/female) andZ11-14∶Ac (600 pg/female) (all other monoenes had different retention times). In field tests, traps baited withZ11-14∶OH alone captured males, but traps baited withZ11-14∶Ac alone did not. Traps baited with a combination ofZ11-14∶OH andZ11-14∶Ac in various ratios did not produce better trap catches thanZ11-14∶OH alone. (Z)-9-Dodecen-1-ol acetate (Z9-12∶Ac), reported by others to be a field attractant, did not produce trap catch in our tests, but in combination withZ11-14∶ OH (98∶2 in septa corresponding to 95:5 in vapor,Z11-14∶OH toZ9-12∶AC) produced a sevenfold increase in catch overZ11-14∶OH alone. IfZ9-12∶AC had been present in extract of SPG at 2-5% ofZ11-14∶OH, it would not have been detected in our GC-MS experiment.