Effects of Truck Based Ultra-Low Volume Mosquito Adulticides on Honey Bees (Apis mellifera) in a Real World Scenario

Abstract

Honey bees are crucial pollinators for many economically important fruit crops. The recent honey bee colony decline in the United States and other regions of the world has caused concern among commercial beekeepers, research groups, the government, and the general public. The role of pesticides in recent honey bee declines has not been fully determined. In Louisiana, it is a common practice to spray truck based ultra-low volume mosquito adulticides in Integrated Mosquito Management Programs to control mosquitoes and minimize the risk of vector borne viruses such as West Nile, chikungunya, and Zika. This study measured the effects of truck based ultra-low volume (ULV) mosquito adulticides on honey bees in a real world scenario. We looked at mortality, colony health (number of adult bees, brood quantity and quality), and detoxification enzymes (esterase and glutathione S-transferase) on honey bees from sentinel bee hives in Baton Rouge, Louisiana over a seven week period. The mosquito adulticides used by mosquito control programs during this study were Scourge, Duet and Deltagard. We did not find significant differences in honey bee mortality, colony health (frames of bees and brood quality) or detoxification enzymes among our control and treatment sites over the seven weeks. We found differences in brood quantity between control and treatment; however only two colonies at one of our treatment sites skewed the result in brood quantity. Although the findings of this study suggests that there is no effect of truck based ultra-low volume mosquito adulticides on bee mortality, colony health, and detoxification enzymes on honey bees, there might be deleterious effects if mosquito adulticides are used inappropriately.