Protecting honeybees from pesticides: a call to action

Abstract

Honeybees are the most essential and economically dominant pollinator species in food crop production globally. Studies have shown that honeybees pollinate up to 87.5% of flowering and edible plants (Ollerton, Winfree, and Tarrant 2011). Therefore, survival of bees and bee diversity are critical for sustaining pollination services over time. However, bee populations have been in decline and the fall in the honeybee population has had a negative impact on crops, including fruits, vegetables, and fodder crops. In the United States, colony collapse disorder (a disease phenomenon characterized by the sudden and rapid loss of the honeybee population) is responsible for 30–40% of the disappearance of honeybee colonies (Lebuhn et al. 2013). Of the native bee species in North America and Mexico, 27% of mason bees and 50% of leafcutter bees are vulnerable (proposed for threatened status under the Endangered Species Act [ESA]). In North America, 26% of bumble bee species (Bombus spp.) are threatened (that is, listed as endangered under the ESA), with broad decreases occurring across the genus. Following its final appearance in 2006, the bumble bee (B. franklini) became the first bee in the western continental United States to acquire ESA protection in 2021. Furthermore, the western bumble bee (B. occidentalis) in western North America has been petitioned for ESA listing after sustaining 93% population losses over two decades (Janousek et al. 2023). In the United Kingdom, 54% of the honeybee population has been lost in the last few decades (Potts et al. 2010). Chinese beekeepers have experienced unusual colony losses and a drop in bee population (Kluser et al. 2010). In contrast to Western countries, practically all of the bees that pollinate Indian crops are wild honeybees and other, non-Apis pollinators. According to Gallai et al. (2009), more than 40% of honeybees declined in India over the last 25 years. Because bees are the most critical pollinators of agricultural crops, their extinction threatens world agriculture. Pollinators, notably bees, are responsible for one-third of all food consumed globally. Without bees and without seed-eating birds, certain mammals, including humans, would have a less nutritious diet. If this trend continues, nutritional crops such as fruits, nuts, and many vegetables will be increasingly exchanged for basic crops such as rice, maize, and potatoes, resulting in an imbalanced diet. Coffee, apples, almonds, tomatoes, and cocoa are just a few of the crops that rely on pollination and would be extinct if bees and other pollinators were not present. Countries must adopt more pollinatorfriendly and environmentally sustainable food policies and systems. Global bee population decline poses a major threat to a wide range of plants vital to human well-being and livelihoods, and countries should do more to protect these key allies in the battle against hunger and malnutrition. Pesticides play a key role in the reduction of honeybees. Scientists are continuing to investigate the impact of various insecticides and their application methods on bee health. The most researched chemical is a type of agricultural pesticide known as ‘neonicotinoids’. These compounds are systemic, which means they enter the plant’s circulatory system and spread to all tissues. They are effective after only one application and only impact invertebrates, making them less sensitive to runoff and less hazardous to humans, birds, livestock and other animals. In principle, the pesticide should not harm bees because they consume pollen and honey rather than plant tissue. However, these pesticides have been identified in trace concentrations in pollen grains and since bees transport pollen back to their colonies for sustenance, one pollen grain with trace chemicals accumulates to dangerous quantities within beeswax.