A new study found that the overall health of honey bee hives actually improves in the presence of agricultural production.
The authors evaluated the impacts of row-crop agriculture, including the traditional use of pesticides, on honey bee health. Results indicated that hive health was positively correlated to the presence of agriculture. According to the study, colonies in a non-agricultural area struggled to find adequate food resources and produced fewer offspring.
According to the study, hives located in areas with high to moderate agricultural vegetation grew faster and larger than those in low or non-agricultural areas. Researchers suggest the greater population sizes enabled better colony thermoregulation in these hives, as well. Meanwhile, bees located in a non-agricultural environment were challenged to find food. Although fewer pesticide contaminants were reported in these areas, the landscape did not provide sustainable forage. In fact, during the observations, two colonies in the non-agricultural areas collapsed due to starvation.
Photo by S. Stewart, courtesy of UTIA.
Disruptions and fluctuations in brood rearing were also more notable in a non-agricultural environment. Interestingly, brood production was highest in the location that exhibited a more evenly distributed mix of agricultural production, forests and urban activity. Researchers also evaluated trapped pollen from each colony for pesticide residues. Low concentrations of fungicides, herbicides and insecticides were identified, but at levels well below the lethal dose for honey bees. Imidacloprid was the only neonicotinoid detected, also at sub-lethal levels. Agricultural pesticides, particularly neonicotinoids, are considered by some activists to be a key factor in honeybee populations, though honeybee populations are actually high. The study found that higher exposure to pesticides in agricultural environments did not result in measurable impacts on colony productivity.
“One possible explanation for this finding could be the elevated urban activity in this location,” says Mohamed Alburaki, lead author and post-doctoral fellow with the University of Tennessee Department of Entomology and Plant Pathology. “Ornamental plantings around homes or businesses, or backyard gardens are examples of urban activity that increase the diversity of pollen in an area. Greater pollen diversity has been credited with enhancing colony development.”