RADIATION-INDUCED STERILITY IN MALE POTATO-TUBER MOTH PHTHORIMAEA-OPERCULELLA ZELLER (LEP, GELECHIIDAE)

Newly emerged adult males (0-18h) potato tuber moth Phthorimaea opercu lella were irradiated with various doses (5, 10, 15, 25, 35, and 45 Kr ad) of gamma irradiation. Mating ability and frequency of mating of th e males were decreased when they were irradiated with 25 Krad and abov e, whereas their longevity was not affected by the irradiation. The me an number of eggs per female was decreased at 35 and 45 Krad, and 91% sterility was induced when males were irradiated with a dose of 45 Kra d. The competitiveness values of P. operculella males were reduced whe n they were irradiated with high doses. However, these values were ris en when high ratio of irradiated males to normal males was used.