Studies on species diversity of fruit flies on ash gourd in the New Alluvial Zone of West Bengal

Present experiment was conducted in farmers’ fields at Gangnapur village, Nadia district, during April and May 2022. Observations were conducted using cue lure and methyl eugenol traps at five-day intervals across eight sampling sessions. The cue lure trap recorded the highest diversity index (0.598) during the 4th interval, declining to 0 by the 8th interval, with an overall diversity index of 0.377, species evenness of 0.272, and species richness of 0.457. Conversely, the methyl eugenol trap showed the highest diversity (1.198) in the 4th interval, decreasing to 0 in the later intervals, with overall diversity, evenness, and richness indices of 0.538, 0.334, and 0.708, respectively. Five species were identified, with Z. cucurbitae being the most dominant. Peak diversity in both traps coincided with the active fruiting phase of ash gourd, suggesting a close ecological link. This study provides the first comprehensive account of fruit fly species diversity in ash gourd ecosystems in this region, offering critical insights into their population dynamics.