By Molly Redfield
Pesticides. Sprayed across vast expanses of farm land, they have become a ubiquitous part of industrial agriculture. But there may actually be more consequences to their use than we had previously predicted. A recent study headed by Chensheng Lu at Harvard University connects the rising phenomena of bee hive abandonment, known as Colony Collapse Disorder (CCD), to the use of a family of pesticides called neonicotinoids.
Scientists believe that pesticide use is a major factor in the recent worldwide decline in bee populations (Photo credit: Robert Gutowski)
Introduced in the early 1990s, neonicotinoids are today incorporated widely in industrial agricultural operations because they are readily taken up by plants, acting quickly and effectively on crop pests. But these pesticides also affect non-target pest species. When bees forage, they are exposed to neonicotinoids that are present in both the plants vegetative tissue and the nectar they feed on.
In Lu’s study, exposure to the neonicotinoid imidacloprid is shown to impact the homing ability of honeybees. Lu and his colleagues further suggest that neonicotinoids may be one of the central causes of CCD and the subsequent massive decline in bee populations since 2006. They link this decline in the U.S. and worldwide to the emergence of genetically engineered corn seed treated with neonicotinoids. Other factors such as pathogens and declining habitats further aggravate the loss of bee populations.
The United States Department of Agriculture (USDA) recognizes the importance of bees and restoring their populations. According to the USDA, bees contribute approximately US$15 billion in added crop values in the United States and are responsible for pollinating about 75 percent of US grown fruits, vegetables, and nuts. Additionally, their continued decline could cost the U.S. billions of dollars. Truly, short-term gains in crop yields with neonicotinoid use must be reconsidered in light of the repercussions pesticides have on the populations of these incredibly important pollinators.
Molly Redfield is a research intern with the Nourishing the Planet project.
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