Background: Honeybees are of economic importance not only for honey production but also for crop pollination. Nationwide,
the value of the increased crop yield and quality achieved by honeybees is estimated at $14.6 billion. Thus, bee health is critical
for the success of pollination-based agriculture, which produces about a third of our diet in the United States (US). Unfortunately,
the number of honeybee colonies in the US has declined by more than 40% in the last few years. A combination of causal factors,
including exposure to pesticides, parasites, and beekeeping practices are believed to be the culprit for the increased colony
mortality. In this study, we compared pesticide residues under two different beekeeping management practices (conventionally
and organically-managed apiaries).
Results: We found no pesticide residues in adult bee samples collected from organically managed hives; whereas, trace amounts
of the fungicide chlorothalonil and the pyrethroid insecticide fluvalinate were found in adult bees collected from conventionally
managed hives. Unlike honey harvested from organically managed hives, a concentration of 12.45 ppb of the formamidine amitraz
was found in honey harvested from conventionally managed hives. Residues of several pesticides were found in wax from both
conventionally and organically managed apiaries; except for coumaphos at 225.3 ppb, levels were generally lower in organically
managed hives and the highest concentration of insecticide detected in wax from conventionally managed hives was fluvalinate
at 251.5 ppb. Two pyrethroid insecticides (fluvalinate and bifenthrin) were found in pollen samples collected from organically
managed hives; in contrast, several classes of pesticides were detected in pollen samples from conventionally managed hives where
the highest residue level was that of the fungicide pyraclostrobin at 100 ppb.
Conclusion: In general, pesticide residues were higher in conventionally managed apiaries than in organically managed ones.
There were more chemical residues in the pollen samples from conventionally managed apiaries than organically managed ones.
Farmers and beekeepers should work together to promote honeybee health.