EFFECTS OF GAMMA-RADIATION AND LOW-TEMPERATURE ON PINK-BOLLWORM (LEPIDOPTERA, GELECHIIDAE) MATING ACTIVITY

Lower percentages of male pink bollworm, Pectinophora gossypiella (Sau nders), moths exposed to 20 krad were observed in copula with untreate d female moths during the first 6-h dark period after irradiation as c ompared to untreated male and female moths. Irradiated male moths also spent less time in copula, but irradiation had no effect on numbers o f spermatophores per mated female or percentages of mated females with sperm in their spermathecae. Lower percentages of untreated female mo ths were mated when they were paired with previously mated males than when paired with virgin males. The sequence in which females were mate d to an irradiated male did not affect the transfer of spermatophores. However, the percentages of eggs hatched was higher from the first ma ted female compared to the second and third mated female. There were n o significant effects of 10 or 20 krad exposure on female mating or ti me in copula. However, significantly lower percentages of mating of tr eated and untreated females occurred with sequentially provided male m oths on days 2, 3, or 4 following the first observed female mating. Ma ting of males exposed to 20 krad and held for 4, 6, 8, or 16 h at 4.4- degrees-C was significantly reduced during the first dark period follo wing treatment compared to untreated male moths. Percentages of male m oths mating on day 3 after exposure to 20 krad and 4.4-degrees-C for 4 h following treatment were not significantly different from percentag es of non-irradiated male moths held at 26.7-degrees-C for 4 h prior t o pairing with untreated female moths.