Submitted to: Journal of the Mosquito Control Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2006
Publication Date: 9/1/2006
Citation: Xue, R.D., Kline, D.L., Arshad, A., Barnard, D.R. 2006. APPLICATION OF BORIC ACID BAITS TO PLANT FOLIAGE FOR ADULT MOSQUITO CONTROL. Journal of the Mosquito Control Association. 23:497-500. Interpretive Summary: Adult mosquito control is based primarily on the aerial application of insecticides. But insecticides can pollute the environment, kill beneficial insects, and lead to insecticide resistance in the mosquito population if improperly applied. ARS Scientists at the Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, FL, in conjunction with scientists at the University of Florida are studying new ways to control mosquitoes without using insecticides. One technique they have developed for this purpose is to combine a toxicant (boric acid) with a bait (sugar/water solution) and to make the bait mixture available on plant foliage as food for adult mosquitoes. In outdoor tests, the use of boric acid baits in this manner killed 80-100% of adult mosquitoes after 48 hours while significantly reducing mosquito landing rates on human subjects. Scientists believe that boric acid baits can be used to reduce adult mosquito populations. If designed for economy and ease of use, boric acid bait applications to plant foliage could provide a safe, non-insecticidal, point-source control method for mosquitoes in urban and suburban environments.
Technical Abstract: Boric acid (1%) in 5% sugar-water bait solution was applied as a spray to the foliage, stems, and other surfaces of plants for control of adult Aedes albopictus, Culex nigripalpus, and Ochlerotatus taeniorhynchus. Initial studies outdoors in small (1.42 m3) screened cages showed that exposure of male and female mosquitoes to 1% boric acid bait for 48 hours resulted in 80 to 100% mortality in Ae. albopictus and >98% mortality in Cx. nigripalpus and O. taeniorhynchus. At 48 hours post-treatment, in large (1178 m3) outdoor screened cages, 1% boric acid bait applied as a spray to plant surfaces significantly reduced the landing rates of Ae. albopictus and Cx. nigripalpus on a human subject, as well as the numbers of these two species captured in mechanical traps, compared with responses for adults exposed to 5% sugar-water solution only (control). Boric acid bait treatments in large screened cages did not significantly reduce landing rates or trap captures of Oc. taeniorhynchus. The application of boric acid baits to plant surfaces may be an effective adulticidal method for selected species of pest/disease vector mosquitoes.