External morphology of antennal sensilla of both sexes of irradiated and non-
irradiated Trogoderma granarium were studied with scanning electron microscopy.
The number and distribution of antennal sensilla were also determined. Five types of
sensilla could be distinguished on the flagella of both sexes: sensilla chaetica, long
trichoid sensilla, short trichoid sensilla, basiconic sensilla I and II. The sensilla
chaetica are probable tactile mechanosensila, where as both types of sensilla trichoid
and basiconic sensilla type I liekly function in olfaction. Suggested function for
basiconic sensilla type II include hygrol thermoreception and chemoreception. The male antenna is considerably larger than that of the female; in both
sexes, sensilla on the antennal segments were most abundant on the apical
segments, where sensilla trichoid were particularly concentrated. External structure, general distribution and relative number of sensilla in
irradiated specimens were affected. One-Day old pupae were more affected by
gamma radiation more than 4 - day old. Essential difference were indicating clear
sexual dimorphism. In male morphological features were regarded as modification for
sex pheromone reception. The effect of sterile dose of gamma radiation on olfactory
receptors may reduce the biological activity .of insects.