Impact of Systemic Pesticides on Non-Apis and Wild Bee Populations: A Review

Abstract

The widespread use of systemic pesticides such as neonicotinoids and phenylpyrazoles poses a serious threat to wild and non-Apis bee populations. Unlike managed honeybees, wild bees, including bumble bees (Bombus spp.), solitary bees (Osmia spp.), and stingless bees (Meliponini spp.) have diverse foraging behaviors, nesting habits, and life cycles, which increase their vulnerability to pesticide exposure. These chemicals, absorbed by plants and distributed into pollen, nectar, and guttation fluids, expose bees through several routes, causing both lethal and sublethal effects. Sublethal exposure can impair learning, memory, navigation, and brood development, ultimately reducing reproductive success and population stability. This review explores the systemic pesticides, their mechanisms of action, and their ecological impact on non-Apis bees, which are key pollinators vital for natural ecosystems and agriculture. It emphasizes the urgent need for stricter regulations, broader implementation of Integrated Pest Management (IPM), habitat restoration, and long-term research on pesticide persistence and combined stressors, while promoting safer, pollinator-friendly pest control alternatives.