The Future of Insect Repellent Discovery and Development

, 2007). All exhibit several of the following characteristics: i) Large amounts of compound must be applied ii) These compounds disrupt behavior on contact or from a short distance iii) They affect the behavior of a wide-range of arthropods iv) Their mode of action has not been well-established. The develop-ment of area repellents, as opposed to topical repellents, is even more challenging since AI dilution is greater in a space treatment than on a surface area. The original DEET composition patent was filed in 1946 by Samuel I. Gertler although the identification of its repellent properties was not made until 1952 at the U.S. Department of Agriculture (Bernier & Tsikolia, 2011). Starting with its release as a publicly-available product in 1957, DEET eventu-ally replaced most of the other repellent AIs during the 1960s and 1970s. It has dominated the market due to low cost, long duration on the skin, broad spectrum of activity, and good toxicological profile (Frances, 2007). Because of these proper-ties and its long history of use, DEET is the gold standard by which all other repellents are compared.The first evidence of the molecular mode of action of DEET suggested this compound selectively inhibits hetero-meric complexes of insect odorant receptors (ORs) (Ditzen