Seasonal Occurrence of Melon Fruit Flies (Zeugodacus cucurbitae Coq.) and Its Natural Enemies on Bitter Gourd

Abstract

Aim: To study the seasonal occurrence of cucurbit melon fly and correlation study with weather parameters to know the impact of abiotic environmental factors on the activity of melon fruit fly concerning infesting the fruits of bitter gourd in crop ecosystem. Place and Duration of Study: College of Agriculture, VNMKV Parbhani, Maharashtra. Studies during two seasons Rainy and Summer 2021 and 2022 respectively. Methodology: The experimental plot was kept unsprayed throughout the crop season. The observation was recorded as soon as the incidence was noticed from five randomly selected plants at weekly intervals. The observations of fruit flies were recorded from the day of fruit formation to the last picking of the fruit. The damaged and healthy fruits were recorded at eachpicking to knowing the percentage fruit infestation by fruit flies. Results: Fruit fly was the major pest of bitter gourd in fruit damage. The fruit damage record range was 15.65 to 59.33 per cent in the rainy season whereas, 28.99 to 61.14 per cent in the summer season. The per cent fruit infestation shows a significant and positive correlation with no. of maggots per fruit (r = 0.857 and 0.905) during both seasons respectively. Weather parameters like morning relative humidity (MRH) and rainfall the during rainy season show significant and positive correlation (r = 0.87 and r = 0.71 respectively) whereas, during the summer season significant and positive correlation (r = 0.77) with MRH and significant and negatively correlated with (r = - 0.66) minimum temperature. The record of larval pupal parasitoid Psyttalia fletcheri (Silvestri) and it was discovered that 16% of the population was parasitized during the experimental period Conclusion: The infestation may vary from season to season, region to region and concerning variety also. Here the infestation range was higher during the summer season, which may be because of the coincidence with the fruit season of mango in that area.