| Abstract |
The Mediterranean fruit fly, Ceratitis capitata, (Wiedemann) (Diptera: Tephritidae) is one of the most serious, wide-spread pests of citrus fruits and many other fruits. Among the methods used to control it, the biological Sterile Insect Technique (SIT) is based on the release of sterile mass-reared males into the environment with aim to reduce the reproductive potential of the wild population. The procedure of adaptation to mass-rearing conditions often leads to changes on the insect behavior and physiology that result to sexual isolation in the wild populations. In the present work, in laboratory conditions couples of insects, which were kept in small cages, were studied in respect with copulation behavior (age, frequency, duration and rhythm of mating and remating) over the first two weeks of adult life. Survival was studied over seven consecutive weeks. Several combinations of adult nutrition and laboratory and wild flies were studied in the above study. The study included experiments on the effect of: a) Sterilization of the laboratory-reared males with γ-radiation from a Co60 gamma source on the pupal stage, one day before adult emergence of a white female pupae genetic sexing strain [Τ (Υ;5)1-61]. b) Adult nutrition of laboratory-reared and wild flies (collected on pupal stage from infested fruits). Nutritional treatments included standard mass-rearing adult food (25% hydrolyzed yeast, 75% sugar) in solid or in liquid (syrup) form and dry commercial sugar. The mating competitiveness between lab (sterilized) and wild males for wild females (1:1:1), total sex ratio 2:1, was also studied. Sterilization didn't affect substantially the mating success and longevity of the laboratory-reared males, while feeding on protein plus carbohydrate in syrup form was found to enhance their sexual performance and survival. On the contrary, deprivation of protein from wild males didn't affect their mating ability and longevity; nevertheless, it had negative effect on the longevity of wild females. Food deprivation after emergence allowed young, sterilized laboratory males to live 2,4 days only. Sterilized lab-males were found to compete adequately with wild males in matings with wild females in the cages. Wild females showed preference for protein fed laboratory-reared males. No particular sexual isolation was detected between the two strains (laboratory and wild). Wild females were more selective in their mating activity than laboratory-reared females. In conclusion, supply with standard laboratory adult food in syrup form following adult emergence, had a positive effect on mating and survival of laboratory-reared males.
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Επίδραση της τροφής ενηλίκων και της στείρωσης στην ικανότητα σύζευξης και στην επιβίωση στελέχους μαζικής εκτροφής της μύγας της Μεσογείου Ceratitis capitata Wiedemann (Diptera:Tephritidae)
