Olfactometric Evaluation of Spatial Repellents forAedes aegypti

Abstract

The spatial repellency responses of Aedes aegypti (L.) to deet, dehydrolinalool and linalool were evaluated using a dual port olfactometer. In the absence of human attractant mixture, each of the three chemicals resulted in activation and/or orientation of mosquitoes to the chemical source. Linalool was the most attractive compound. In the presence of human attractant mixture, activation and/or orientation of mosquitoes to each of the three chemicals was reduced. We compared reductions in mosquito responses to each of the three chemicals, in the presence of human attractant mixture, to estimate spatial repellency. As expected, lowest spatial repellency (7.3%) was observed using human attractant alone. Highest spatial repellency (33.6%) was observed using a combination of linalool and dehydrolinalool. Deet did not manifest spatial repellency, whereas linalool and dehydrolinalool alone, and in combination, exhibited spatial repellency.

Mosquitoes smell and avoid the insect repellent DEET

“…The DEET-sensitive ORN was also stimulated in a dose-dependent manner by terpenoid compounds, such as thujone, eucalyptol, and linalool ( Fig. 2), which have already been reported as repellents (13)(14)(15).…”

Host-Seeking and Blood-Feeding Behavior of Aedes albopictus (Diptera: Culicidae) Exposed to Vapors of Geraniol, Citral, Citronellal, Eugenol, or Anisaldehyde

“…Among the strategies of mosquito control, the use of plant volatiles or other attractive substances in attractant-baited traps or as spatial repellent agents has much attention (Kline and Lemiro 1998;Kline et al 2003). Attractantbaited traps are intended to reduce mosquito population, while using spatial repellent agents are intended to interfere with a mosquito's host-seeking ability, thus reducing potential contact with humans and other animal hosts (Nolen et al 2002).…”

“…Attractantbaited traps are intended to reduce mosquito population, while using spatial repellent agents are intended to interfere with a mosquito's host-seeking ability, thus reducing potential contact with humans and other animal hosts (Nolen et al 2002). The combination of these two approaches is considered the latest technology in mosquito management (Nolen et al 2002;Kline et al 2003) and could achieve greater success than traditional approaches such as area-wide application of insecticides.…”

“…More recently, Jhumer et al (2007) reported that 14 compounds from the flower odor of Silene otites, including benzaldehyde, eugenol, and linalool, were attractive to both Culex pipiens molestus and Aedes aegypti. On the other hand, many studies have been devoted to the evaluation of plant based substances, i.e., essential oils and their constituents, in searching for effective spatial repellents and/or alternatives to synthetic repellents (Barnard 1999;Dogan and Rossignol 1999;Tawatsin et al 2001;Kline et al 2003;Trongtokit et al 2005;Amer and Melhorn 2006;Hao et al 2006;Kang et al 2009). As a result, a multitude of natural compounds have been identified as repellents of various mosquito species.…”

Identification of compounds from Etonia rosemary (Conradina etonia)

“…When eugenol was chemically removed from the O. suave plant extract, repellency to Aedes aegypti mosquitoes dropped from 100 min of protection time to 0 min, thereby implicating eugenol as the compound that elicited the greatest repellent properties [33]. Linalool, a terpenic alcohol detected in all three solvent extracts is a superior spatial repellent at high concentrations compared to DEET for A. aegypti mosquitoes [34].…”