BIOLOGICAL STUDIES OF THE PEACH FRUIT FLY, BACTROCERA ZONATA (SAUNDERS) (TEPHRITIDAE : DIPTERA) ON THREE ARTIFICIAL DIETS AT THREE CONSTANT TEMPERATURES

Abstract

Effects of three artificial diets (bran, molasses and bagasse) at three constant temperatures (20, 25 and 30oC) on some biological aspects of peach fruit fly, Bactrocera zonata, were studied under laboratory conditions. The shortest durations of immature stages (egg incubation, larval and pupal durations) were obtained at 30oC especially, on brain diet. Mean durations of the three immature stags were 1.76, 5.25 and 7.04 days, respectively. While the high-est mean percentages of egg hatching, pupation and adult emer-gence were occurred on bran diet at 25 °C. Mean percentages of egg hatching, pupation and adult emergence were 92.6, 90.49 and 94.27 on bran diet at 25°C. However, the lowest female fecundity and percentages of egg fertility were obtained from larvae, which reared on bagasse diet at the three tested temperatures. The means were 174 eggs and 60.84%, 386 eggs and 78.85% and 286 eggs and 66.43 % at 20, 25, 30°C, respectively. While, the highest female fecundity and percentages of eggs fertility were occurred on bran diet at 25 and 20oC being 683 eggs and 90.50% and 293 eggs and 75.88%. On contrast, at 30oC fecundity was higher on molasses diet (438 eggs) than on bran diet (331 eggs), but eggs fertility was still the highest on bran diet (87.08 %). Female longevity was prolonged at 20oC when their larvae were reared on the three diets the mean being 108.43, 124.57, 153.13 days at bran, molasses, bagasse diets, respectively. Also, male longevity was prolonged at 20oC when their larvae were reared on the three tested diets, it means being 96.97, 111.43 and 137.72 days, respectively. From the obtained results, it can be concluded that bran diet was the most preferable diets for rearing B. zonata specially under 25oC.