Novel Arthropod Repellent, BioUD, Is an Efficacious Alternative to Deet

Abstract

For >50 yr, N,N-diethyl-3-methylbenzamide (deet) has been the standard for arthropod repellents and has been an important tool to protect people from disease agents carried by ticks, mosquitoes, and other arthropods. However, some people avoid using deet because of concerns about adverse health effects. In 2007, a new repellent, BioUD, with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) plants, was registered by the U.S. Environmental Protection Agency. In the current study, repellent efficacy of BioUD was compared using arm-in-cage studies with 7 and 15% deet against the mosquitoes Aedes aegypti (L.) and Aedes albopictus Skuse. No differences were found in mean repellency over 6 h after application between BioUD versus 7 and 15% deet for Ae albopictus. For Ae. aegypti, no differences were found over the same time period for 7% deet. Compared with 15% deet, BioUD mean repellency was lower over the 6-h test period. Human subject field trials were conducted in North Carolina, United States, and Ontario, Canada, comparing the repellency of BioUD to products containing 25 and 30% deet. BioUD provided the same repellency or was more efficacious than 25 and 30% deet, respectively, in these studies. Laboratory trials were conducted to determine the repellent activity of BioUD against the American dog tick, Dermacentor variabilis (Say), on human skin and cloth. BioUD repelled ticks at least 2.5 h after application to human skin. On cloth, no differences in mean repellency were found through 8 d after application between BioUD and 7% deet. In a two-choice test for BioUD versus 15% deet on filter paper, ticks spent significantly more time on the deet-treated surface than the BioUD-treated surface. Based on these studies in toto, BioUD is an efficacious alternative to deet in its repellent activity.

Efficacy of the new repellent BioUD® against three species of ixodid ticks

“…Two-choice bioassay: BioUD vs. DEET (head-to-head comparison) Witting-Bissinger et al (2008) showed that BioUD Ò with 7.75% 2-undecanone in head-tohead comparisons using filter paper choice assays was more repellent than 15% DEET against unfed American dog tick adults. In the current study, dose-response studies were conducted to better assess the relative effectiveness of the two repellents (Fig.…”

“…Resistance of L. hirsutum f. glabratum to insect herbivory is due in part to the presence of 2-undecanone (Kennedy 2003). Witting-Bissinger et al (2008) showed BioUD Ò was an efficacious repellent against D. variabilis in laboratory studies on treated human skin, cloth, and filter paper. The rat acute oral and dermal toxicity and rabbit dermal irritation toxicity tests resulted in BioUD Ò being rated as category IV (the lowest toxicity level) by the EPA.…”

Comparative Efficacy of BioUD to Other Commercially Available Arthropod Repellents against the Ticks Amblyomma americanum and Dermacentor variabilis on Cotton Cloth

“…Because the presence of a host, the specific field conditions under which a repellent might be used and/or the specific assay conditions used for repellent testing might affect repellent performance, more research is needed to fully understand the activity of BioUD compared with other available technologies. However, the studies described in this paper and others 18,19 on and off the skin of human hosts thus far suggest that BioUD is an efficacious alternative to DEET and other commercially available arthropod repellents for use against ticks. …”

“…27 Previously we showed that BioUD applied to cotton cheesecloth was highly repellent against D. variabilis for at least 8 days after treatment. 18 In this study, we examined repellency of BioUD against A. americanum for 7 weeks. Mean percentage repellency was > 90% for the first 5 weeks and did not decline significantly until the sixth week.…”

“…17 In laboratory studies, BioUD was repellent to D. variabilis on cotton cheesecloth, filter paper, and human skin. 18 In addition, BioUD applied to cotton cheesecloth was found to be highly repellent against D. variabilis for at least 8 days after treatment. 18 BioUD also provided significantly greater percentage repellency than 98.1% DEET against adult A. americanum and blacklegged ticks, Ixodes scapularis Say, in choice bioassays on treated filter paper compared with untreated controls.…”