Female calling behaviour and male response to the sex pheromone in Thaumetopoea pityocampa (Den. and Schiff.) (Lep., Thaumetopoeidae)

Female calling behaviour and male response to natural and synthetic pheromone sources were used for a Portuguese population of the winter pine processionary moth Thaumetopoea pityocampa (Den. and Schiff.). Virgin females 1-5 days old were studied, the mean calling longevity being 3.3 ± 0.7 days. Calling started ≃3 h after the onset of scotophase, and 7 h after emergence, lasting, nightly, for 6.4 ± 0.7 h, and was not affected by female age. A drop in air temperatures during the first half of scotophase and an increase in light intensity at dawn apparently determined the onset and termination of calling. Male flight activity began, on average, 3 h before the females started emitting pheromone, and was similarly affected by air temperatures and light intensity. The attractivity of traps baited with synthetic pheromone (TP056A; Yne 11, Z13-16AC) was compared with that of virgin females. Male flight activity was monitored in central and southern Portugal, using pheromone traps, and seen to last between 6 and 10 weeks, with a major peak occurring, in all sites, at the beginning of September.