Comparative analyses of age-stage, two-sex life table and host preference of Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae) on different hosts

The melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae) is an important pest of cucurbit crops in the Oriental and warm regions of the world. We conducted an age-stage, two-sex life table study of Z. cucurbitae on four different hosts, viz cucumber (Cucumis sativus), ridge gourd (Luffa acutangula), bitter gourd (Momordica charantia) and pumpkin (Cucurbita pepo) under laboratory conditions at 25 ± 1°C, 65 ± 5% relative humidity and a 14:10 h (L:D) photoperiod. The developmental time from egg to pupa was shortest when reared on cucumber (15.4 days), and longest when reared on pumpkin (17 days). The intrinsic rate of increase (r) of the Z. cucurbitae population on cucumber, ridge gourd, bitter gourd and pumpkin was 0.1143, 0.1062, 0.0071 and 0.0089 per day, respectively. The net reproduction rate ( R 0 ) was highest on cucumber (77 offspring per female) and lowest on bitter gourd (15.9 offspring per female). The mean generation time (T) ranged from 35.9 days when reared on ridge gourd to 38.7 days when reared on bitter gourd. Larval hatching rate, pupation rate and adult eclosion rate were highest when reared on cucumber compared to other hosts. In host preference experiments (choice and no-choice tests), the flies were most attracted to cucumber and oviposited most on cucumber when compared to other hosts. We found that cucumber is a suitable host for Z. cucurbitae growth and development and can be used for mass rearing of this fly species under controlled conditions for research purposes.