Crop Pollination Exposes Honey Bees to Pesticides Which Alters Their Susceptibility to the Gut Pathogen Nosema ceranae
The research paper investigates the impact of pesticide exposure on honey bees (Apis mellifera) during crop pollination and its subsequent effect on their susceptibility to the gut pathogen Nosema ceranae. The study is motivated by the alarming decline in honey bee populations and the increasing demand for insect-pollinated crops, raising concerns about pollinator shortages. Researchers collected pollen from honey bee hives across seven major crops (almond, apple, blueberry, cranberry, cucumber, pumpkin, and watermelon) to analyze the types and loads of pesticides present and to assess how these field-relevant pesticide blends affect the bees' susceptibility to Nosema infection.
The findings revealed that honey bees often collected pollen from weeds and wildflowers rather than the target crops, indicating a need to consider pesticide exposure from surrounding areas. A total of 35 different pesticides were detected in the pollen samples, with high levels of fungicides. Notably, the insecticides esfenvalerate and phosmet were found at concentrations exceeding their median lethal doses in some samples. The study also established a correlation between higher fungicide loads in pollen and increased Nosema infection rates in bees, suggesting that fungicides, typically considered safe, may have detrimental effects on bee health.
The research emphasizes the importance of understanding the sub-lethal effects of fungicides and other chemicals on honey bees, advocating for further studies on the interactions between pesticides and pathogens. The results highlight the need for beekeepers to be aware of pesticide applications not only in the fields where their bees are placed but also in nearby areas that may contribute to pesticide drift.
This research paper is significant in the field of entomology and agricultural science as it addresses the critical issue of honey bee health in the context of agricultural practices. It contributes to ongoing discussions about the role of pesticides in pollinator decline, providing empirical evidence of the negative interactions between pesticide exposure and pathogen susceptibility. The findings underscore the necessity for more comprehensive research on the effects of pesticide mixtures and their sub-lethal impacts on bee health, which is vital for developing effective management strategies to protect pollinators. For readers, particularly those involved in agriculture, beekeeping, and environmental conservation, the article offers valuable insights into the complexities of pesticide use and its implications for pollinator health and agricultural productivity.
