Population dynamics of melon fruit fly, Bactrocera cucurbitae  (Coq. ) was studied on cucumber  (Cucumis sativus L.) during kharif and rabi season of  2014 – 2015 at Dharwad and Navalur by using cue-lure traps. Incidence of fruit fly was high (55.67fruit flies/trap/week) on the crop planted during kharif and low (19.67 fruit flies/trap/week) on the crop planted in rabi. The level of fruit infestation by B. cucurbitae was 70.90 per cent during kharif 2014). Pooled incidence data of melonfruit fly showed significant positive correlation with minimum temperature (r= 0.388*), morning(r= 0.372*) and evening relative humidity (r= 0.427).