Electroantennogram, flight orientation, and oviposition responses of Aedes aegypti to the oviposition pheromone n-heneicosane

Abstract

Oviposition pheromones specifically influence the females of many insects to lay eggs in the sites resulting in more egg deposition. A previous report describes the principal role of n-heneicosane (C(21)) identified and characterized from the larval cuticle of Aedes aegypti (L.) in attracting the gravid mosquitoes to oviposit in treated substrates among other chemical components. However, the means by which this compound is perceived by the females for oviposition has not been reported. In this study, we have recorded the peripheral olfactory responses from the antenna of Ae. aegypti from 10(-7) g to 10(-3) g doses of n-heneicosane. The EAG response of female mosquitoes increased in a dose-dependent manner with increasing stimulus strength. In the orientation assay using Y-maze olfactometer, female mosquitoes were attracted to the odor plume of 10(-6) g and 10(-5) g dose, while the higher dose of 10(-3) g plume enforced repellency to gravid mosquitoes. The response to oviposition substrates by gravid Ae. aegypti females differed across the range of concentrations of n-heneicosane under multiple choice conditions, larger number of eggs were deposited in 10 ppm (10 mg/l) solutions compared to lower and higher concentrations indicating 10 ppm was most attractive. Application of n-heneicosane at 10 ppm in breeding habitats will be a useful method to attract the gravid mosquitoes using ovitraps for surveillance and monitoring. The possible use of this compound in monitoring of mosquito population in endemic areas in relevance to integrated vector management strategies is discussed in detail.

Behavioral and electrophysiological responses of Culex quinquefasciatus to certain fatty acid esters

“…These cues include color and optical density of the water, texture and moisture, temperature and reflectance of the oviposition substrate (Bentley and Day, 1989). The chemical factors involved in oviposition site selection by mosquitoes have gained much interest in recent years (Beehler et al, 1994;George et al, 1986;Knols et al, 2004;Millar et al, 1992;Seenivasagan et al, 2009;Seenivasagan and Vijayaraghavan, 2010;Takken and Knols, 1999).…”

Chemosensory Cues for Mosquito Oviposition Site Selection

“…eggs, larvae, and pu pae) could encourage conspecific mosquitoes to use the same site (Soman and Reuben 1970, Trimble and Wellington 1980, Wachira et al 2010, Wong et al 2011. Pheromones from immature stages that stimu late their conspecifics to lay eggs have been identified (Mboera et al 2000a,b;Mendki et al 2000;Ganesan et al 2006;Seenivasagan et al 2009). However, high densities of mosquito immature stages in water gener ate competition, with negative effects on larvae and the emerging adults (Ho et al 1989, Reiskind andLouni bos 2009).…”

Behavioral Responses and Bioefficacy of Some Aromatic Amides Against Aedes aegypti

“…The odor was delivered by blowing air through the cartridge. The orientation behavior and number of mosquitoes caught or exhibiting ßight activity in or to either odor plume ßowing from respective arms were observed in the olfactometer (Seenivasagan et al 2009). …”

“…aegypti maintained for Ͼ25 yr in the insectary at 27 Ϯ 2ЊC and 75 Ϯ 5% RH (Seenivasagan et al 2009) was used for these experiments. Four-to 5-d-old female Ae.…”