Preliminary investigation of aggregation dynamics and mating pheromones associated with Aedes aegypti (Diptera: Culicidae)

Locating a suitable mate is a key determinant of population size and reproductive fitness and to accomplish this, Aedes aegypti L., as with other mosquitoes, mate in swarms consisting of tens to thousands of individuals. Presumably, these swarms are not random events but form in response to a cue (or cues) causing mosquitoes to aggregate at a single location. A simple but prevalent mechanism for swarm formation is for individuals to alter flight activity and actively seek mates by following signals such as wing beats and/or pheromones; cues associated with the mosquitoes themselves, not the environment.

To test for evidence of pheromonal cues in Ae. aegypti, we preformed a series of behavioral experiments using a dual-port olfactometer. Our preliminary results indicate that females do sense a cue, and interestingly, were more likely to fly toward males than vice versa. Males were observed to initiate swarming behavior in the test chamber, rather than flying directly into the collection ports. Using GC-MS, we tentatively identified three volatile organic compounds, produced by Ae. aegypti, which may influence swarming behavior. Combined, our data indicate the presence of chemical cues associated with aggregation of Ae. aegypti; however, an individual's response to this signal is influenced in part by its gender. A more detailed understanding of swarm and its underlying mechanisms may lead to the development of alternative mosquito control methods.