Mating competitiveness in field cages of a new genetic sexing strains of the Mediterranean fruit fly (Diptera: Tephritidae) in Argentina

JORGE L. CLADERA; MARÍA T. VERA; GRACIELA CALCAGNO; JUAN C. VILARDI; ERIC STOLAR; DIEGO F. SEGURA; NATALIA PETIT-MARTY; PAULA GÓMEZ CENDRA; ARMANDO ALLINGHI; GABRIELA BONPLAND; MARCELA RODRIGUERO; FLAVIA KRSTICEVIC; LAURA HANSEN; GONZALO SEGADE; KARINA BARBORINI; TAMARA HEER; DONALD O. MCINNIS

Mendoza

Congreso; 4th Meeting of the Working Group on Fruit Flies of the Western Hemisphere; 2001

Genetic sexing strains (GSS) are being developed worldwide in the Mediterranean Fruit Fly, (medfly) Ceratitis capitata Wiedemann (Diptera: Tephritidae), for use in sterile insect technique (SIT) programs. GSS have significantly increased the efficiency of medfly SIT programs and for this reason, efforts are being focused on strains in which the sexes are separated early and are adaptable to mass-rearing. Among other things, the utility of these new strains for the SIT depends upon the ability of laboratory-reared males to efficiently compete with wild males in mating with wild females under field conditions. The present study evaluated the mating ability of a new medfly GSS, the Cast 191 line, in competition with wild males, and with another GSS: Seib 6-96, which is being released in an active SIT program in Argentina. At the same time, the effect of irradiation on the mating competitiveness of the Cast 191 strain was assessed. The results obtained for this new strain are very promising, inasmuch as, even after irradiation, flies from this strain performed as well as wild males in competition for wild females. The only difference of the new strain compared to wild flies came in a shorter copulation time for irradiated Cast 191, and even this difference was not significant once Bonferroni’s correction was applied.