DEVELOPMENT OF ARTIFICIAL LARVAL DIET AND OPTIMIZATION OF STERILE MALE RATIO OF ORIENTAL FRUIT FLY, BACTROCERA DORSALIS (HENDEL)

Abstract

A study was conducted to develop artifitial larval diet and optimization of the sterile male ratio of oriental fruit flies, Bactrocera dorsalis (Hendel) for possible field application of Sterile Insect Technique (SIT). Population fluctuations of the fruit fly were monitored in Atomic Energy Research Establishment campus, Ganakbari, Savar, Dhaka from January 2012 to December 2012 using methyl eugenol baited Mcphail traps. High level of fruit fly population was found throughout the year in all the study areas except February. Mean monthly capture was highest in May. Different ratios between irradiated and unirradiated male of fruit flies were allowed to mate with a fixed number of unirradiated females of fruit flies in different cages to find out the rate of suppression against wild population. In case of efficiency of artifitial larval diet the highest hatching percentage and the lowest larval duration was observed from the 4.87-4.89 pH. But based on the highest number of pupae, percent flier, percent adult emergence and lowest pupal duration, diet having 5.22-5.26 pH was found to be economical and suitable for mass scale rearing of B. dorsalis. Radiosensitivity of pupae was found to be decreased as age increased. Highest pupal duration and no normal adults were found after imposing gamma radiation in 5-days old pupae treated with 60 Gyga dose. Radiation significantly increased the unemergence and decreased the normal emergence of fruit fly. The sterilizing doses were recorded as 60 Gy for 5-days old pupae. The 1:9 ratio of unirradiated male and irradiated male was found as the best for suppression of wild population of B. dorsalis in both laboratory and field trials.