LSU AgCenter to research impact of mosquito spray on bees

A $167,000 grant from the U.S. Environmental Protection Agency will help researchers at the LSU Agricultural Center determine whether lab-tested safety precautions to protect honey bees from mosquito spraying actually work in the field.

Lead researcher Kristen Healy, assistant professor of entomology at the LSU Agricultural Center, said most of the work on insecticide safety around bees has been done in lab settings with little testing of how those safety measures work in the real world.

Last spring, mosquito control staff and beekeepers met to discuss concerns that mosquito spraying could harm bee hives.

Healy said the mosquito control sprayers and beekeepers approached her early last year about how to measure the effectiveness of safety measures.

Although mosquito sprayers work to minimize any impact by having certain spray distances from hives and not spraying in those areas where it could affect hives, researchers have not measured how well these tactics work, Healy said.

The issue is complicated in Southern states because the heat and humidity force bees out of the hive even at night as they fan the hive to keep it cool, said Todd Walker, director of the East Baton Rouge Mosquito Abatement and Rodent Control office.

“When we’re wanting to do our aerial sprays and truck sprays, they’re on the outside of the hive,” Walker said.

In other cooler climates, the bees would be inside the hive. In addition, if spraying is done too early in the day, there’s a chance bees out foraging could be affected by the mosquito spray.

“Bees are highly susceptible to what we spray,” Walker said.

The research will start this spring in the laboratory where the toxicity levels of the mosquito sprays will be measured in bees.

Then, there will be several field trials over the spring and summer to do overall monitoring but also to set up bee hives in increasing distances from a mosquito sprayer to see how far the insecticide travels and the concentration of the chemical found on the hives over various distances.