Journal of Experimental Agriculture International

Fruit flies are important pests of bitter gourd and other cucurbitaceous crops, and their seasonal abundance is strongly influenced by prevailing weather conditions. Temperature, relative humidity and rainfall can affect adult activity and population fluctuations, while cue-lure traps provide a practical means of monitoring male fruit fly populations. However, information on species-specific population dynamics under different cue-lure trap types in hot and semi-arid agro-climatic conditions remains limited. A field study was conducted during the summer (zaid) season of 2025 at the Agricultural Research Farm and Integrated Farming System unit of Banda University of Agriculture and Technology, Uttar Pradesh, India, to examine the population dynamics of cue-lure-trapped fruit flies in bitter gourd and their relationships with weather parameters under hot and semi-arid agro-climatic conditions. Indigenous cue-lure bottle traps and commercial cue-lure traps were installed at two locations, with three traps of each type at each location. Weekly observations were recorded from the 15th to the 24th Standard Meteorological Week. Six fruit fly species, namely Zeugodacus cucurbitae, Z. tau, Z. duplicatus, Z. caudatus, Bactrocera zonata and B. dorsalis, were recorded. Fruit fly catches varied among trap types, locations and meteorological weeks, and commercial traps generally recorded higher catches than indigenous traps. Correlation analyses showed predominantly negative associations between fruit fly populations and temperature, particularly maximum temperature. Rainfall generally showed positive associations with fruit fly populations, while relative humidity was mostly weakly and non-significantly positive. The magnitude and direction of associations varied among species, trap types and locations. These findings indicate that seasonal fruit fly activity in the bitter gourd ecosystem is associated with prevailing temperature and moisture conditions. Cue-lure trapping can therefore support seasonal monitoring and the timing of fruit fly management under hot and semi-arid conditions.