The Mortality Rate Of Pupae And Adult Of Fruit Fly Bactrocera Cucurbitae Coquillett (Diptera: Tephritidae) Affected By Different Submerging Time And Soil Types Under The Laboratory Treatment

Abstract

Three separate experiments were carried out to investigate the effect of submerging time under water, pupal age and soil types on mortality and rate of emergence of fruit flies pupae to adult stage. Pupae of Bactrocera cucurbitae Coquillett at different ages by hour i.e., 12, 24, 48, 72 and 96 (hrs) were submerged underwater for (1 and 24 hrs). The rate of pupal emergence to adult stage and mortality was investigated. Results showed that emergence and mortality of B. cucurbitae was significantly affected by both submerging time and pupal age. The 12 hrs pupae were more sensitive than 72 hrs pupae, with minimum adult emergence rate and maximum mortality. Results from various submerging times (1, 2, 3 and 4 hrs) on same age pupae also showed similar trends in pupal’s mortality and emergence to adult stage.In further investigation on the effect of four soil texture classes such asclay loam, silt clay loam, sandy loam and pure sand as control, low emergence rate and high mortality was recorded from silt clay loam texture soil as compared to only sand. Hence it is concluded that pupal age, soil texture and under water pupal submergence time has direct effect on the rate of emergence and mortality rate of fruit fly pupae in the soil. Intermittent irrigation of fruit fly host plants standing in clay loam or silt clay loam soil texture may help in controlling the overwintering pupae in the orchards