THE STATUS OF Bactrocera dorsalis AS AN EMERGING PREDOMINANT PEST IN THE COMMERCIAL FRUIT INDUSTRY IN SRI LANKA

Abstract

Fruit flies (Diptera: Tephritidae) are considered the most serious insect pests in the fruit industry worldwide. However, there are no sufficient studies and information on the pest severity and the dominance levels of fruit flies in the fruit industry in Sri Lanka. Hence, the present study aimed to assess the abundance, dominance status, and potential risk of fruit flies in the local fruit market in Sri Lanka. The study was carried out using randomly selected eight (08) fruit stalls (in Galle, Matara, Wellawaya, Monaragala, Ambilipitiya, Kakirawa, Hambanthota, Lunugamwehera) as two stalls in each bio-climatic zone. Adult fruit flies were collected using methyl-eugenol field traps. Trapped flies were identified using standard taxonomic keys. Simpson Population Dominance Index and the Abundance Index for recorded fruit flies were calculated. Four Bactrocera species; B. dorsalis, B. kandiansis, B. correcta and B. latifrons were recorded. Among them, B. dorsalis showed the highest percentage abundance in all selected fruit stalls and in all bio-climatic zones (P<0.05). Out of the four species, B. dorsalis recorded the highest dominance index value (0.61) as the high-dominant fruit fly species. As such, there is an emerging pest risk of B. dorsalis as the predominant fruit fly in the commercial fruit industry in Sri Lanka. These findings will be helpful for fruit exporters, local sellers, cultivators and agriculture authorities in implementing control measures to secure the commercial fruit industry in Sri Lanka.