Field evaluation of various food attractants for the fruit fly Bactrocera species in pear orchard

Field studies were carried out to evaluate the attractiveness of different food attractants viz. protein hydrolysate 10%, torula yeast 10%, yeast instant 7%, casein 5% and sugar molasses 10% towards the fruit fly, Bactrocera species in pear orchard. Different concentrations of food baits (as mentioned above) were prepared in 200 ml of water and transferred to locally designed traps made up of 1.5 liter cold drink plastic bottles. The traps were hung on fruit trees at a height of about 2 m and at appropriate distance from each other. No insecticide was used in the food attractants. Data were regularly recorded at weekly intervals on the total number of B. zonata or B. dorsalis captured their sex ratio and aggregate population density of both the species. Results showed that yeast instant attracted significantly higher population of B. zonata and B. dorsalis and hence the highest cumulative population of both species followed by treatment of sugar molasses and protein hydrolysate. Among all the treatments, torula yeast was found to be the least preferred attractant for B. zonata and B. dorsalis. Sex ratio (%) of B. zonata and B. dorsalis revealed that all the baits attracted significantly higher number of females than males with highest female percentage in protein hydrolyzate and the lowest in sugar molasses. The results showed that yeast instant, sugar molasses and protein hydrolysate were highly effective and could further be exploited in combination with certain chemicals to enhance their effectiveness and developing a strong fruit fly attractant.