Researchers Compare "Natural" Repellents to DEET

Annapolis, MD: October 28, 2015 -- Researchers at New Mexico State University tested 10 commercially available products for their effectiveness at repelling mosquitoes, and the results were published in the Journal of Insect Science. Three of the products (Repel 100® Insect Repellent, OFF® Deep Woods Insect Repellent VIII, and Cutter® Skinsations Insect Repellent) were mosquito repellents that contained DEET as the active ingredient, and four of the products (Cutter® Natural Insect Repellent, EcoSmart® Organic Insect Repellent, Cutter® Lemon Eucalyptus Insect Repellent, and Avon® Skin So Soft Bug Guard) were mosquito repellents that did not contain DEET. The other three products tested were Avon® Skin So Soft Bath Oil, Victoria’s Secret® Bombshell perfume, and Mosquito Skin Patch®, a skin patch with vitamin B1 as the active ingredient.

The products were tested against two mosquito species, the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), both known vectors of dengue fever, chikungunya, yellow fever, and other diseases.

For both species, the researchers found that mosquitoes were strongly repelled by all products containing DEET. For the other products, they found mixed results.

On Aedes aegypti, the mosquito repellents that did not contain DEET either didn’t repel them at all or didn’t have a repellent effect after just 30 minutes. The exception was Cutter® Lemon Eucalyptus Insect Repellent, which had strong repellent effects for the duration of the 240 minute test. The bath oil and perfume effectively repelled mosquitoes for 120 minutes, but the skin patch did not seem to have any repellent effect at any time.

On Aedes albopictus, two of the non-DEET repellents significantly repelled mosquitoes throughout the duration of the study. Furthermore, unlike the resuts for Aedes aegypti, Avon® Skin So Soft Bug Guard had significant repellent effects for 120 minutes. The bath oil and skin patch had no repellent effects on Aedes albopictus, but the perfume repelled mosquitoes for 120 minutes, as it did for Aedes aegypti.

“The results of this study show that not all commercially available mosquito repellents are effective in repelling mosquitoes and that efficacy is also dependent on the species of mosquito that is repelled,” the authors wrote. “Overall, the results from this study confirm that DEET repellents are the most effective mosquito repellents in the market. Although, based on the results from this study, a lemon-eucalyptus oil containing p-menthane-3,8-diol (PMD) [the active ingredient in Cutter Lemon Eucalyptus Insect Repellent] has similar efficacy to DEET repellents.”

Perhaps the most surprising result in the study was the effectiveness of Victoria’s Secret® Bombshell perfume at repelling mosquitoes.

“Our results challenge the notion that floral perfume-scented sprays, in general, attract mosquitoes,” the authors wrote. “Floral fragrances may provide a masking odor resulting in low mosquito attraction rates, but over a shorter duration of time.”

However, the authors do provide a caveat to this finding, noting that “the concentration of perfume we used in this test was rather high and that lower concentrations of the same fragrance might have different effects.”

The full article is available at http://dx.doi.org/10.1093/jisesa/iev125.

The Journal of Insect Science is published by the Entomological Society of America, the largest organization in the world serving the professional and scientific needs of entomologists and people in related disciplines. Founded in 1889, ESA today has nearly 7,000 members affiliated with educational institutions, health agencies, private industry, and government. Members are researchers, teachers, extension service personnel, administrators, marketing representatives, research technicians, consultants, students, and hobbyists. For more information, visit http://www.entsoc.org