QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 25, 2005
Journal of Experimental Biology 208, 2963-2972 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01736

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dekker, T. Articles by Cardé, R. T. Search for Related Content PubMed PubMed Citation Articles by Dekker, T. Articles by Cardé, R. T. Social Bookmarking                         What's this?

Carbon dioxide instantly sensitizes female yellow fever mosquitoes to human skin odours

Teun Dekker^1,*, Martin Geier² and Ring T. Cardé¹

¹ Department of Entomology, University of California, Riverside, CA 92521, USA
² Institut fur Zoologie, Universität Regensburg, Universitätsstrasse 31, Regensburg 93040, Germany

^* Author for correspondence at present address: Division of Chemical Ecology, Department of Crop Science, SLU, Alnarp, SE-23053, Sweden (e-mail: teun.dekker{at}vv.slu.se)

Accepted 6 June 2005

Female mosquitoes are noted for their ability to use odours to locate a host for a blood meal. Two sensory organs contribute to their sense of smell: the maxillary palps, which measure the level of CO₂, and the antennae, which detect other host-released odours. To establish the relative importance and interactions of CO₂ and other body emissions in freely flying mosquitoes, we presented female yellow fever mosquitoes Aedes aegypti L. with broad plumes of human skin odour and CO₂ at natural concentrations and dilutions thereof in a wind tunnel. 3-D video-recorded flight tracks were reconstructed. Activation, flight velocity, upwind turning and source finding waned quickly as skin odours were diluted, whereas in the presence of CO₂ these parameters remained unchanged over more than a 100-fold dilution from exhaled concentrations. Although mosquitoes were behaviourally less sensitive to skin odours than to CO₂, their sensitivity to skin odours increased transiently by at least fivefold immediately following a brief encounter with a filament of CO₂. This sensitization was reflected in flight velocity, track angle, turning rate upon entering and exiting the broad odour plume and, ultimately, in the source-finding rate. In Ae. aegypti, CO₂ thus functions as a `releaser' for a higher sensitivity and responsiveness to skin odours. The initially low responsiveness of mosquitoes to skin odours, their high sensitivity to CO₂, and the sensitization of the olfactory circuitry by CO₂ are ecologically relevant, because rapidly fluctuating CO₂ levels reliably signal a potential host. Possible mechanisms of the instantaneous sensitization are considered.

Key words: Aedes aegypti, mosquito, orientation, sensitisation, host odour, carbon dioxide, human skin odour

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. Ghaninia, M. Larsson, B. S. Hansson, and R. Ignell Natural odor ligands for olfactory receptor neurons of the female mosquito Aedes aegypti: use of gas chromatography-linked single sensillum recordings J. Exp. Biol., September 15, 2008; 211(18): 3020 - 3027. [Abstract] [Full Text] [PDF]

				J. Goyret, P. M. Markwell, and R. A. Raguso Chemical Ecology Special Feature: Context- and scale-dependent effects of floral CO2 on nectar foraging by Manduca sexta PNAS, March 25, 2008; 105(12): 4565 - 4570. [Abstract] [Full Text] [PDF]

				Z. Syed and W. S. Leal Maxillary Palps Are Broad Spectrum Odorant Detectors in Culex quinquefasciatus Chem Senses, October 1, 2007; 32(8): 727 - 738. [Abstract] [Full Text] [PDF]

				J. Y. Kwon, A. Dahanukar, L. A. Weiss, and J. R. Carlson The molecular basis of CO2 reception in Drosophila PNAS, February 27, 2007; 104(9): 3574 - 3578. [Abstract] [Full Text] [PDF]

				C. Faucher, M. Forstreuter, M. Hilker, and M. de Bruyne Behavioral responses of Drosophila to biogenic levels of carbon dioxide depend on life-stage, sex and olfactory context J. Exp. Biol., July 15, 2006; 209(14): 2739 - 2748. [Abstract] [Full Text] [PDF]