Host use preference of fruit flies (Diptera: Tephritidae) among selected cucurbitaceous vegetables in Morogoro, Eastern-Central Tanzania

Abstract

Fruit flies (Diptera, Tephritidae) represent a major threat to cucurbit production in Tanzania. They cause huge economic losses on cucurbit crops. Information on the infestation and yield loss caused by fruit flies on cucurbit crops is vital in designing a sound fruit fly management program. We identified the fruit fly species attacking cucurbit crops (Cucurbitales: Cucurbitaceae): cucumber (Cucumis sativus L.), watermelon (Citrullus lanatus [Thunb.] Matsum. & Nakai) and squash (Cucurbita moschata D.) in the Morogoro region and quantified their incidence and infestation per crop species. A weekly sampling of ten fruits per crop was repeated twice per plot for each zone for five consecutive weeks between March and October 2020. The number of fruit flies emerging from the collected fruits was quantified and infestation per crop species was determined. We observed significant differences in infestation between cucurbit species, across zones and seasons. Squash showed the highest infestation of Zeugodacus cucurbitae (Coquillet) in both zones followed by watermelon. Watermelon was highly infested by Dacus vertebratus (Bigot) in the plateau zone followed by squash. Squash showed the highest infestation of Dacus ciliatus Loew in the plateau zone followed by watermelon. Cucumber had the lowest infestation for all fruit fly species.