Diversity of Tephritid Flies in Sub-Himalayan Region of West Bengal: Baseline Data for Developing Rational Management Practices

Abstract

Six species of tephritid fruit flies, viz., Bactrocera cucurbitae (Coquillett), Bactrocera diversa (Coquillett), Bactrocera caudata (Fabricius), Bactrocera tau (Walker), Bactrocera nigrotibialis (Perkins), and Dacus longicornis (Wiedemann), were trapped in cue lure trap in cucurbit fields, and mean trap catches were 45.00 %, 16.67 %, 11.67 %, 9.50 %, 9.50 %, and 4.80 %, respectively. Using methyl eugenol trap, four species, viz., B. dorsalis (Hendel), B. zonata (Saunders), B. versicolor (Bezzi), and B. correcta (Bezii), were trapped in guava orchards of Cooch Behar district of West Bengal with a mean trap catch of 55.85 %, 20.14 %, 21.00 %, and 3.01 %, respectively. From infested fallen and harvested fruits of mango from a mango orchard of Malda district of West Bengal, the fruit fly species recovered were B. dorsalis (Hendel), B. zonata (Saunders), and B. versicolor (Bezzi), and their proportions were 52.25 %, 27.34 %, and 20.10 %, respectively. Again, after rearing from infested fallen and harvested guava fruits in Cooch Behar district (West Bengal), five species of tephritid fruit flies, viz., B. dorsalis (Hendel), B. zonata (Saunders), B. versicolor (Bezzi), B. caudata (Fabricius), and B. nigrotibialis (Perkins), were obtained. Proportionally, the highest population of B. dorsalis (Hendel) (37.86 %) was noted. Rearing from infested fallen and harvested citrus in orchards of Darjeeling district (West Bengal), B. minax (Enderlein) and B. dorsalis (Hendel) were recorded. Altogether nine tephritid flies were detected through cue lure and methyl eugenol trap catching and infested fallen and harvested fruits of mango, guava, and citrus. The dominant species were B. cucurbitae (Coquillett), B. dorsalis (Hendel), B. minax (Enderlein), B. zonata (Saunders), and B. versicolor (Bezzi). It was also detected that 31.67 %, 36.33 %, and 45.67 % of fruits of mango, guava, and citrus, respectively, were found infested by fruit flies in Northwest Bengal.