Present studies on biology of melon fruit fly, Bactrocera cucurbitae (Coquillett) revealed that the freshly laid eggs were glistening white, slightly curved, tapering at one end while rounded at the other end. The mean length and breadth of the egg were found to be 1.13 ± 0.14 mm and 0.28 ± 0.05 mm. The first and second instars measured 1.49 ± 0.28 and 6.40 ± 0.86 mm in length, respectively, and 0.31 ± 0.07 and 1.21 ± 0.09 mm in breadth, respectively. The third instar was very mobile and measured 9.62 ± 0.87 mm in length and 2.05 ± 0.32 mm in breadth. The puparium measured 5.72 ±0.13 mm in length and 2.46 ± 0.11 mm in breadth. The length and breadth of male was 8.74 ± 0.32 mm and 11.46 ± 1.16 mm, whereas, the female measured 9.94 ± 0.20 mm in length and 15.92 ± 0.74 mm in breadth. The duration of egg incubation, and the larval, prepupal and pupal periods were 16.8 ± 4.9 hours, and 4.5 ± 1.13, 0.8 ± 0.25 and 8.4 ± 0.51 days, respectively. Pre-oviposition and oviposition periods ranged from 10–15 and 12–28 days. Fecundity varied from 58–92 eggs, while egg viability was 86.1 ± 0.54. Sex ratio (male: female) was 1.10 ± 0.14. Longevity of adults was extended to 30–52 days for males and 30–60 days for females when fed either water, molasses and honey or water, molasses and proteinex. Lack of access to water led to sudden death of the flies.