Effects of cyromazine on adult C. capitata (Diptera: Tephritidae) on mortality and reproduction

Abstract

The effects of the insect growth inhibitor cyromazine on Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reproduction after adult treatment were studied. Continuous feeding of the toxicant in the drinking water during 12 d following adult emergence significantly affected fecundity and fertility at high doses and also affected larval development of the progeny. Egg production was reduced by concentrations of 500 μg/ml onward, ranging from 55 to 79.6% reduction, whereas significant reductions in the percentage of egg hatch were only recorded from 5,000 μg/ml onward. Neither gross qualitative nor quantitative differences in the ovaries of treated insects could be detected under the light microscope. Effects on larval development were conspicuous and a significant reduction in the number of pupae formed was recorded at every dose (from 10 μg/ml), reaching 100% for 10,000 μg/ml. Pupal development was not disturbed. Adult longevity was affected only at the high doses. Preoviposition feeding (4 d) did not cause any effect on the studied parameters, although number of eggs laid by untreated females was always higher than that of treated ones.