PORAPAK-Q COLLECTION OF PHEROMONE COMPONENTS AND ISOLATION OF (Z)- AND (E)-14-METHYL-8-HEXADECENAL, SEX PHEROMONE COMPONENTS, FROM THE FEMALES OF FOUR SPECIES OF Trogoderma (COLEOPTERA: DERMESTIDAE)

A major sex pheromone component of each of four Trogoderma species was isolated by aeration of the female beetles and absorption of the volatiles on Porapak-Q. (Z)-14-Methyl-8-hexadecenal was identified as the major component in T. inclusum and T. variabile, and (E)-14-methyl-8-hexadecenal was identified in T. glabrum. Both (Z)- and (E)-14-methyl-8-hexadecenal were found in T. granarium (Khapra beetle), in the ratio 92Z: 8E. In laboratory bioassays, male beetles exhibited arousal and mating responses to the aldehydes, and could discriminate between the geometric isomers. The daily production of the aldehyde was calculated for each species, and other active components were detected. These aeration-absorption studies contrast with earlier studies on macerated beetles, in which the aldehyde was not detected. The efficacy of the aeration-absorption system for collection of the sex pheromones is also described. The absorbent (Porapak-Q) efficiently collected the active pheromone; only minor amounts of activity were left in the other parts of the system.