Population dynamics of fruit flies, Bactrocera spp. in North Western Himalaya

Abstract

Population dynamics of fruit flies, Bactrocera dorsalis, B. zonata and B. diversa were studied through pheromone trapping using methyl eugenol in vegetable gardens and orchards of North Western Himalayan hills. The abiotic factors such as temperature, rainfall, relative humidity and host plants with respect to the population dynamics were analyzed to understand the interactions. A unimodal pattern was noticed in all the species studied with peak incidence from May to October. These were not noticed during January in both the ecosystems. Bactrocera zonata was the predominant species starting from March to August, and afterwards B. dorsalis was observed to outnumber up to December. The fruit fly incidence was positively correlated with maximum and minimum temperature, and when the temperatures fall within the optimum range, the population was at its peak. Host plants exhibited a strong influence on the incidence and abundance but supported them only when favourable environmental conditions exists. Abundance of B. zonata was correlated with brinjal, and tomato supported B. dorsalis as that of its preferred host, mango.