Effect of pheromone concentration on organization of preflight behaviors of the male gypsy moth,Lymantria dispar(L.).

Male gypsy moths (Lymantria dispar L.) in a wind tunnel at 24° respond to decreasing dosages (1 μg to 0.1 pg) of (+)-cis-7,8-epoxy-2-methyloctadecane with a decrease in probability of wing-fanning, an increase in wing-fanning latency, and an increase in the number of behaviors (body jerks, antennal twitches, steps, and wing tremors) preceding fanning. Males initiating any behavior prior to wing-fanning had a 70% probability of wing-fanning and 97% of the males that wing-fanned eventually flew. The sequence of behaviors from quiescence to flight is not organized in a hierarchy, as this concept is used in ethology, nor is it dependent upon the concentration of pheromone. The time-average threshold concentration of pheromone for response of ca. 90% or more quiescent males is ca. 1.9 × 10(-17) g/cm(3) over < 0.3 min.