Almond seed wasp (Hymenoptera: Eurytomidae) sex pheromone: effect of trap type, trap position, blend ratio and time of the day on male attraction

Abstract

Field trials were carried out in order to evaluate some of the factors affecting male response of the almond seed wasp, Eurytoma amygdali Enderlein, to traps baited with the alkadienes (Z,Z)-6,9-tricosadiene and (Z,Z)-6,9-pentacosadiene, the male attractant of this species. The trials were conducted in Latomia, Microthivae, Kanalia and Sykourion (Thessaly, Central Greece) during the 2004 growing season. In all regions, captures in traps baited with a 7:3 ratio of the above blend significantly and positively correlated with male emergence from infested almonds that had been placed in cages in the experimental fields. Traps baited with the 7:3 pheromone ratio were significantly more effective in capturing males than traps baited with the 1:1 ratio, supporting the hypothesis that (Z,Z)-6,9-tricosadiene is the main component of this attractant. Of four trap types tested, Rebel and Lasiotraps attracted significantly more males than Delta and Funnel traps. Height had no effect on trap efficiency; however, males were captured earlier in the day in traps placed 2.3 m above grown than in traps placed 1.3 m above grown. Most male activity was recorded between 10 and 12 h, but captures were continuously recorded during the entire monitoring interval from 6 to 17 h.