UF/IFAS scientists say a blacklight trap captures more mosquitoes than non-targeted insects, as mosquito control officials try to save money and time in their efforts.Image credit: UF/IFAS Florida Medical Entomology LabThe finding will help mosquito control districts more quickly identify mosquitoes before decisions are made to spray, said Phil Kaufman, an associate professor and veterinary entomologist with UF’s Institute of Food and Agricultural Sciences.

Mosquito control districts can run 50 or more traps in a night during the mosquito season to keep track of mosquito populations.  But mosquito control officials do not want to capture insects unnecessarily, a practice that takes time and money, Kaufman said. Those unintended captures include moths, beetles and other flies.

“The traps are returned to the mosquito control district office, and people have to sort through all of the moths, beetles and more to find and remove the mosquitoes that have to be identified to see which species are a problem or to test them for West Nile and other viruses,” Kaufman said. “Having fewer non-target insects makes their job easier.” 

For the new study, Chun-Xiao Li, a visiting scientist from China working in Kaufman’s lab, evaluated several traps on a farm near Elkton, in St. Johns County, in collaboration with the Anastasia Mosquito Control District. She tested the New Jersey and CDC light traps – considered standard methods – as well as a UV trap, a blacklight trap and a yellow fluorescent light trap, in the fall of 2013.

Li found the blacklight trap collected the most mosquitoes, while capturing the fewest “non-target insects,” those that are not part of the surveillance system and that mosquito control officials do not want to kill. The blacklight trap resembles the CDC trap, except it uses a black light instead of the incandescent “white” light of the CDC trap, Kaufman said.

The study was published in the current issue of the journal Florida Entomologist.

“Black lights produce a light that is considerably more attractive to insects,” Kaufman said. “Humans cannot see ‘UV,’ so what we are really seeing in a ‘black light’ or bug zapper light are the wavelengths that don’t quite make it to the UV spectrum. Insects, however, see it quite clearly, and many like it.

“The light traps essentially catch anything that is small enough to get sucked in when they get close to the mouth at the top of the trap,” he said.