GAMMA-RADIATION EFFECT ON PRODUCTION OF 4 PHEROMONAL COMPONENTS OF MALE MEDITERRANEAN FRUIT-FLIES (DIPTERA, TEPHRITIDAE)

An analytical method enabling the collection and gas chromatographic a nalysis of delta-1-pyrroline that is released from calling males of th e Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was develop ed. Using this procedure along with previously reported methods for th e analyses of geranyl acetate, ethyl-(E)-3-octenoate, and E,E-alpha-fa rnesene, we compared pheromone production among fruit-reared, factory- reared fertile, and factory-reared sterile male Mediterranean fruit fl ies in Guatemala. There were no significant differences in pheromone p roduction (ng per male per hour) from 0600 to 1400 hours. In collectio ns made from 1400 to 1700 hours, however, factory-reared fertile males produced significantly more of the three major terpene components (ge ranyl acetate, ethyl-(E)-3-octenoate, E,E-alpha-farnesene), whereas th e factory-reared sterile males produced significantly more of the four -component blend (the three terpenes plus delta-l-pyrroline) than frui t-reared males. Sterile males produced a significantly higher percenta ge of ethyl-(E)-3-octenoate, based on the four component pheromone ble nd, during the 1000- to 1400-hour collections. Thus, the primary diffe rence in pheromone production among the tested flies was that the frui t-reared males produced pheromone over a shorter time during the day. Gamma radiation did not affect adversely the amount of total pheromone produced but did affect component ratios in the pheromone blend.