The influence of host presence, age and mating on calling behaviour of the female spotted bollworm, Earias vittella, was studied under a 14L:10D photoperiod. Onset of calling was earlier in the presence of a host and 93% of the females initiated calling in its presence on day one after emergence, compared to 67% in its absence. A majority of the females initiated calling during the 10th hour of the first scotophase and thereafter the initiation shifted to earlier hours as age advanced. Females generally called longer in the presence of a host. The mean time spent in calling, from the 1st to the 10th day increased from 56 to 152 min in the absence of a host, and from 77 to 234 min in its presence. Most of the females resumed calling after mating, but the mated females exhibited a significant reduction in calling performance when compared with the virgin females.
