Wind tunnel studies on the effects of secondary sex pheromone components on the behaviour of male Egyptian cotton leafworm moths, Spodoptera littoralis

ABSTRACT. The responses of adult male Spodoptera littoralis (Boisd.) (Noctuidae) to components of the female sex pheromone were examined in a wind tunnel. The responses of male moths from both Egyptian and Cretan stocks to the primary 'attractant' (Z, E)-9,11 tetradecadienyl acetate (III), were compared with the responses to III combined with various percentages of the secondary components tetradecyl acetate (I), (Z)-9-tetradecenyl acetate (IIA), (E)-11-tetradecenyl acetate (IIB), IIA and IIB combined, and(Z, E)-9,12-tetradecadienyl acetate (IV). Analysis of the flight behaviour recorded on videotape showed that with one exception (IV), the secondary components increased the males' success in reaching the source and increased the length of time they spent at the source. In most cases, increasing the relative percentage of the secondary component caused a reduction in the number of males responding. The results are compared with those obtained in field trials with S.littoralis.