ARS | Publication request: Laboratory Evaluation of Mosquito Repellents Against Aedes Albopictus, Culex Nigripalpus, and Ochlerotatus Triseriatus (Diptera; Culicidae)

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 30, 2004
Publication Date: July 1, 2004
Citation: Barnard, D.R., Xue, R. 2004. Laboratory evaluation of mosquito repellents against aedes albopictus, culex nigripalpus, and ochlerotatus triseriatus (diptera; culicidae). Journal of Medical Entomology.

Interpretive Summary: Public concern over the spread of disease by mosquitoes has increased during the West Nile virus epidemic in the U. S. One way to prevent mosquito bites is to use personal protection, which allows individuals a choice between avoiding mosquito habitat, excluding mosquitoes with physical and chemical barriers, treating clothing fabric with toxicants, and/or using topical repellents (on skin). Topical repellents are the most commonly used personal protection method; however, the effectiveness of topical repellents is influenced by many factors and can be highly variable among mosquito species. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL in cooperation with scientists at the University of Florida, made this study as part of an effort to develop guidelines for personal protection and the use of repellents against mosquitoes that transmit encephalitis viruses (West Nile, St. Louis, La Crosse) to humans. They tested 12 commercially available repellents against one exotic mosquito species (Aedes albopictus) and two native mosquito species (Culex nigripalpus, Ochlerotatus triseriatus). The results showed that the repellents containing deet, as well as the repellents Autan (KBR3023), Repel (paramenthanediol), and Bite-Blocker (soy oil + vanillin) prevented bites by all three mosquito species for at least 4 hours. Autan, Repel, and Bite Blocker are effective deet-alternative repellents and can be used for protection from attack by mosquito vectors.

Technical Abstract: Three synthetic mosquito repellents (Autan, Off!, Skinsations) and nine natural product-based repellents (Bite Blocker, ByGone, GonE!, IR3535, Natrapel, Neem Aura, Sunswat, MosquitoSafe, and Repel) were tested in the laboratory against Aedes albopictus Skuse, Culex nigripalpus Theobald, and Ochlerotatus triseriatus (Say). When estimated protection time responses for each repellent were averaged by mosquito species, Autan, Bite Blocker, and Repel were shown to prevent biting for 7.2 h; ByGone, GonE, NeemAura, and SunSwat prevented bites for 1.6 h. Against Ae. albopictus, estimated mean protection times (eMPT) for Off! and Repel exceeded 7.2 h and ranged from 5.0 to 5.7 h for Autan, Bite Blocker, and Skinsations. Bygone, GonE, NeemAura, and SunSwat repelled Ae. albopictus for 0.2 h. Autan, Bite Blocker, Off!, and Repel prevented Oc. triseriatus bites for an average of 7 h but ByGone, GonE!, NeemAura, and Sunswat provided no protection against this species. All 12 repellents provided eMPTs 2.8 h against Cx. nigripalpus (maximum: 8.3 h for Bite Blocker). When the eMPT for each repellent (for all species) was divided by the eMPT for 7% deet (Skinsations), the order of repellent effectiveness and the corresponding Repellency quotients (Rq) were: Repel (1.58) >Autan (1.50) =Off! (1.50) >Bite Blocker (1.20) >Skinsations (1.0) >IR3535 (0.67) >MosquitoSafe (0.65) >Natrapel (0.48) >Bygone (0.33) >NeemAura (0.29) >SunSwat (0.29) >GonE (0.19).