A bioassay of the pheromone of Trogoderma granarium males as an attractant for both sexes of the species

The pheromone of Trogoderma granarium males was subjected to two bioassays intended to examine its effect on the two sexes of the species. The tests were made with concentrations ranging from 0.1 to 200 males per ml of solvent. The weakest reaction of males and females was observed in concentrations of 0.1 and 0.4/cc respectively. The peak reaction of the males was attained in concentrations of 12.5/cc and of the females in 50/cc. Both the males and the females show a marked reduction of response at higher concentrations. A significant difference in response was observed between treated and control specimens (p < 0.001) at concentrations corresponding to peak response; the difference was nonsignificant near the lowest concentrations of the two sexes used. The initial response was seen to rise steeply during the first 15 min.; this primary rise was followed by a more gradual secondary rise later on. The results of our study seem to suggest that the volatile substance secreted by T. granarium is more in the nature of an aggregation agent, rather than being a sex attractant.