Biology and biometrics of melon fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae) on some cucurbitaceous crops
Yona Pradhan, MK Gupta, Chethan Kumar N and IY Longkumer
The studies pertaining to biology and biometrics of melon fly, Bactrocera cucurbitae were performed by rearing the insect on seven different cucurbitaceous crops (hosts) viz., ash gourd, bitter gourd, bottle gourd, cucumber, pumpkin, ridge gourd and snake gourd at mean temperature of 27.30 °C and relative humidity 86.39% in laboratory. The order of preference of hosts based on incubation period (hours) were: ash gourd (19.35) < bitter gourd (19.56) < snake gourd (19.91) < cucumber (19.99) < bottle gourd (20.08) < ridge gourd (20.63) < pumpkin (20.66). The order of hosts on the basis of fecundity (no. of eggs/female) were: bitter gourd (77.50) > snake gourd (63.90) > ash gourd (60.22) > ridge gourd (59.39) > cucumber (57.08) > pumpkin (48.55) > bottle gourd (48.06). Morphometric measurements of life stages of B. cucurbitae revealed that freshly laid eggs were glistening white, slightly curved, elongated and tapering at one end while rounded at the other end. The mean length and breadth of the eggs were 1.28 to 1.38 mm and 0.22 to 0.33 mm, respectively. The full grown larvae (maggots) were very mobile and measured 8.92 to 9.66 mm in length and 1.74 to 2.05 mm in breadth.