Exploring the synergistic toxicity of synthetic pesticides and their impact on development and behavior of Honeybee (Apis mellifera L.)

Abstract

In recent years, there has been an increasing concern regarding the impact of pesticide exposure on pollinators, particularly honeybees (Apis mellifera L.). This concern arises from their crucial role in maintaining ecological balance and global food production. Therefore, an extensive investigation has been conducted to explore the intricate relationship between pesticides and the biological development of honey bees in the Rahim Yar Khan region. This study assessed the impact of four pesticides (Emamectin benzoate, Chlorpyrifos, Imidacloprid, and Acetamiprid) on honey bee eggs, larvae, and adult bees under controlled laboratory conditions. The pesticides were applied at concentrations of 10%, 30%, and 50%, as per regional agricultural recommendations. A zero-toxicity control was also included for comparison. Toxicity evaluations were conducted through contact exposure, and Probit and regression analyses were performed using SPSS software to comprehensively assess the toxicity profiles. The study revealed significant adverse effects on the immediate behavioral responses of A. mellifera following pesticide exposure. These effects included heightened agitation, narcotic-like symptoms, audible hovering, crawling, ceased food-sharing behavior, and reduced proboscis extension. Chlorpyrifos exhibited the highest toxicity against adult bees, while Emamectin Benzoate had the least toxicity. Regarding honey bee eggs, Chlorpyrifos, Imidacloprid, and Acetamiprid were notably more toxic, whereas Emamectin Benzoate exhibited the least toxicity. The impact on larvae varied across developmental stages and pesticides, with Imidacloprid, Chlorpyrifos, and Acetamiprid causing significant mortality, while Emamectin Benzoate showed lower toxicity. The study highlights that Emamectin Benzoate demonstrates lower toxicity compared to other insecticides. This emphasizes the importance of balancing effective pest management with the preservation of pollinator health. The findings underscore the need for informed and sustainable approaches to pesticide use, taking into consideration the potential repercussions on honeybee development and behavior.