Host Preference and Performance of Fruit Flies Bactrocera zonata (Saunders) and Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) For Various Fruits and Vegetables

Abstract. The fruit flies (Diptera: Tephritidae) are polyphagous insect pests, therefore, the purpose of this study was to examine the effects of different host species on their preference and offspring performance. Host choice experiments were done for fruit flies Bactrocera zonata (Saunders) and Bactrocera cucurbitae (Coquillett) by using different fruits and vegetables. Host preference for oviposition was determined by incubating fruits and vegetables to natural infestations by Bactrocera in the field, and their larvae reared and adults maintained in the laboratory. Comparative host preference of the B. zonata fruit fly was studied on mango, peach and apple fruits in field experiments. The mango was recorded as most preferred host followed by peach and apple, due to the maximum number of pupae formed (173.17), pupae weight (6.40 mg) obtained and emergence of adult fruit flies (84.53%). The vegetables, bitter gourd, brinjal, muskmelon and pumpkin were tested for the relative host preference of fruit fly B. cucurbitae. The bitter gourd was found as most preferred host demonstrating the maximum pupae formation (134.08), pupae weight obtained (4.91 mg) and percent adult emergence (82.64%) of fruit flies. Brinjal was observed as moderately preferred host, while, muskmelon and pumpkin were sorted out as least preferred hosts. These results provide experimental support that flies can respond differently to the host experienced in the field and the hosts that are of advantageous to the pests may be more adapted. Results further imply that host preference of fruit flies can shift towards suitable hosts and if hosts which provide a proper breeding situation become scarce then alternative hosts are accepted. These findings confirm that the host choice and preference of the fruit flies have the impacts on both pre-harvest and post-harvest countermeasures of horticultural crops.