author(s)
Nagendra Kumar and Nripendra Laskar

abstract
Self-made rectangular PET plastic jars around 1 liter capacity were used and having four circular holes of 2 cm in diameter on four sides of the jar just below the shoulder of the bottle (i.e. 1/ 3^rd from top) openings for entry of flies of different colour viz red, blue, green, black, yellow, orange and white. In addition to that, transparent PET plastic jars were also used as a trap. An experiment was conducted to evaluate the colour preference of trap by the fruit fly, different coloured traps were used in field condition using cuelure as an attractant at Pundibari, Coochbehar, West Bengal during the year 2017 and 2018 at farmer field. Marked differences were recorded in different colours trap catches range from 12.72 to 3.97 flies/ trap/ day. Efficacy of different coloured traps in capturing B. cucurbitae from Days After Installation (DAI) has been depicted that in yellow coloured trap captured significantly the highest mean number of B. cucurbitae (30.14 flies/ trap/ day) followed by orange, green, red, white, black, transparent and blue coloured traps with catches of 25.95, 22.26, 18.21, 15.52, 13.55, 10.69 and 9.07 flies/trap/week, respectively at 7^th DAI. When overall mean values of trap-catch were considered DAI, yellow coloured trap attracted a significantly highest number of fruit flies (12.72 fruit flies/trap/day) followed by orange coloured trap (10.82 fruit flies/trap/day). The least number of fruit flies was attracted to blue coloured trap (3.97 fruits flies/trap/day) followed by transparent trap (4.74 fruits flies/trap/day).