Assessment of Behavioural Changes in Wild Drosophila Fed on Normal and High Caloric Diet under Stress of Beta-Cyfluthrin

Abstract

Beta-cyfluthrin, a synthetic pyrethroid insecticide, affects the nervous system by altering voltage-gated sodium channels, leading to prolonged neuronal excitation. In Drosophila melanogaster, exposure to beta-cyfluthrin—even at sub-lethal doses—has been shown to induce significant behavioural changes. One prominent effect is impaired locomotion, typically observed through reduced climbing ability, which suggests neuro-muscular dysfunction. Feeding behaviour is also altered; exposed flies often consume less food, potentially due to chemosensory disruption or systemic stress. Reproductive behaviour suffers as well, with both male courtship activity and female receptivity declining after exposure, indicating effects on pheromone signaling and mating motivation. Cognitive functions are impacted, as flies show reduced performance in learning and memory assays, likely due to impaired synaptic transmission in brain regions such as the mushroom bodies. Additionally, treated flies display increased grooming and periods of hyperactivity followed by lethargy—signs consistent with neurotoxic stress. These behavioural disruptions can significantly reduce overall fitness and reproduction, highlighting the ecological risks associated with widespread beta-cyfluthrin use. Drosophila serves as an effective model to evaluate such sub-lethal toxicological impacts, and further studies are warranted to explore long-term effects and underlying molecular mechanisms. The increasing use of synthetic insecticides such as beta-cyfluthrin in agricultural and domestic environments poses significant risks to non-target organisms, including wild insect populations. Among these, Drosophila melanogaster a widely used model organism in behavioural and toxicological studies—offers critical insights into the interaction between diet, environmental toxicants, and neurobehavioural outcomes. This study investigates the behavioural responses of wild Drosophila fed on either a normal diet or a high caloric diet when exposed to sub-lethal concentrations of beta-cyfluthrin, a type II synthetic pyrethroid known for its neurotoxic properties. Wild Drosophila specimens were collected from natural habitats and acclimatized under controlled laboratory conditions. The high caloric diet was formulated by enriching the standard cornmeal-agar medium with additional glucose, simulating energy-dense food sources often found in anthropogenic settings. Beta-cyfluthrin exposure was administered through ingestion by incorporating a sub-lethal concentration into the feeding medium over a 48-hour period.