Oviposition Preference and Survival of Zeugodacus cucurbitae and Zeugodacus tau under Laboratory Conditions

Abstract

Fruit flies are economically important pests of cucurbit crops. This study investigated the oviposition preference and maggot survival of Zeugodacus cucurbitae and Z. tau in a choice test using six potential host crops with marketable-sized fruits, namely cucumber (Cucumis sativus), squash (Cucurbita pepo), bitter gourd (Momordica charantia) bottle gourd (Lagenaria siceraria), sponge gourd (Luffa cylindrica), and pumpkin (Cucurbita moschata). The experiment was conducted under laboratory conditions at the Plant Quarantine and Pesticide Management Centre, Lalitpur, April September 2024. Adult fruit flies were obtained by culturing of fruit fly infested pumpkin fruits in the laboratory. In the choice experiment, the host preference of Z. tau was ranked from the highest to lowest as follows: pumpkin cucumber sponge gourd > squash > bottle gourd > bitter gourd, whereas Z. cucurbitae preference were as; squash > bitter gourd > cucumber > sponge gourd > pumpkin > bottle gourd. The oviposition period of Z. tau was 43—74% which was longer than that of Z. cucurbitae; however, Z. cucurbitae showed a higher daily fecundity (3.80 ± 0.40 eggs/female/day) than Z. tau (2.55 ± 0.20 eggs/female/day). The immature survivability was evaluated using a completely randomized design With three replications. Both fruit fly species performed the highest egg hatchability and adult emergence on squash, and the lowest was recorded on bottle gourd for Z. cucurbitae and on bitter gourd for Z. tau. Only about of eggs or pupae failed to develop into adults. This finding demonstrates species-specific host preference underlying importance for targeted sustainable fruit fly management.