LARVAE OF ZEUGODACUS CUCURBITAE (MELON FRUIT FLY) GROWN ON VARYING NATURAL FOOD CONTENTS EXPERIENCE SIGNIFICANT EFFECT ON THEIR WEIGHT AND BIOCHEMICAL PARAMETERS.

Melon fruit flies, Zeugodacus cucurbitae infest fruits of cucurbit plants and make them unpalatable. Their ubiquitous presence across the globe is an indication that they are highly adaptive to varying environment. Its larval stage burrows inside the fruits eating soft contents and growing up to its third instar stage. There are ample evidences that food provided at developing stages may cause substantial variation in the external morphology of insects. Since, Z. cucurbitae larvae grow on different vegetable crops, it was aimed to see whether the host species cause variation in the weight and biochemical characteristics during its larval (pre-adult) stage. In the present work, we reared larvae on three different foods, i.e., pumpkin, long gourd and bitter gourd and observed the influence of these varying foods on their weight and the total contents of triglycerides, protein and glucose. The results of this study indicated that the larval weight significantly varied between two genetically different strains grown on varying foods. Within the strain, food provided at larval stage also caused its marked impact on the larval weight. The impact of food consumed at larval development was also analysed on their biochemical parameters. Larval triglyceride level varied significantly between the strains as well as due to varying food provided at their larval development. The rearing food caused variation on total glucose content of the third instar larvae. Larvae fed on bitter gourd possessed maximum content of glucose in both the strains. However, strain and food together did not leave significant effect on the glucose content. The total protein was found to significantly differ between the larvae of the two strains fed on varying food. [ABSTRACT FROM AUTHOR]