Knowledge of mosquito dispersal is critical for vector-borne disease control and prevention strategies and for understanding population structure and pathogen dissemination. We determined Aedes aegypti flight range and dispersal patterns from 21 mark-release-recapture experiments conducted over 11 years (1991-2002) in Puerto Rico and Thailand. Dispersal was compared by release location, sex, age, season, and village. For all experiments, the majority of mosquitoes were collected from their release house or adjacent house. Inter-village movement was detected rarely, with a few mosquitoes moving a maximum of 512 meters from one Thai village to the next. Average dispersal distances were similar for males and females and females released indoors versus outdoors. The movement of Ae. aegypti was not influenced by season or age, but differed by village. Results demonstrate that adult Ae. aegypti disperse relatively short distances, suggesting that people rather than mosquitoes are the primary mode of dengue virus dissemination within and among communities.

The familiar buzz of flying mosquitoes is an important mating signal, with the fundamental frequency of the female's flight tone signalling her presence. In the yellow fever and dengue vector, Aedes aegypti, both sexes interact acoustically by shifting their flight tones to match, resulting in a courtship duet. Surprisingly, matching is made not at the fundamental frequency of 400 Hz (female) or 600 Hz (male), but at a shared harmonic of 1200 Hz, which exceeds the previously known upper limit of hearing in mosquitoes. Physiological recordings from Johnston's organ (the mosquito's "ear") reveal sensitivity up to 2000 Hz, consistent with our observed courtship behavior. These findings revise widely accepted limits of acoustic behavior in mosquitoes.Mosquito-borne diseases such as malaria, yellow fever, and dengue continue to afflict millions, even after decades of work to control vector populations. Despite this effort, basic aspects of mosquito biology are not fully understood, including mating behavior, an important target for vector control. We now describe investigations in A. aegypti that require revision of the current understanding of mosquito mating behavior. Since Johnston(1) first suggested in 1855 that mosquitoes could perceive sound, over 14 studies have been published on sound production and hearing in A. aegypti (2-17)( Table S1). The buzz of a flying female mosquito acts as a mating signal, attracting males. Typically, the behaviourally salient frequency component of flight tone is the fundamental frequency of wing beat, between 300-600 Hz depending on species (8). However, mate attraction is not simply a matter of a male passively hearing and homing in on a 400 Hz tone. For example, males and females of the non-blood feeding mosquito, Toxorhynchites brevipalpis, modulate their 300-500 Hz wing beat frequencies to match each other (18). Thus, acoustically-mediated mate attraction involves active modulation by both sexes, creating a duet.We show here that males and females of the dengue and yellow fever vector A. aegypti also modulate their flight tones when brought within a few centimeters of each other. This modulation, however, does not match the fundamental wing beat frequency of around 400 Hz (female) or around 600 Hz (male), but a shared harmonic of around 1200 Hz (Fig 1). Consistent with this, a neurophysiological examination of the ears of A. aegypti, shows response in both males and females up to 2000 Hz (Fig 2). These results are surprising, since over decades of behavioral and physiological studies had concluded that male mosquito ears (antennae and associated Johnston's organ) are tuned to 300-800 Hz and deaf to frequencies above 800 Hz (8,19). The present study also directly addresses the issue of auditory competence in female †To whom correspondence should be addressed. * These authors contributed equally to this workBehavioral and physiological experiments demonstrate intersexual acoustic interactions by the yellow fever and dengue vector mosquito, Aedes aegypti, that call for ...

Adult female Aedes aegypti (L.), the vector of dengue and yellow fever viruses, have an affinity for feeding on human blood and a tendency to forego feeding on sugar. This observation challenges two tenets of mosquito biology: (1) mosquitoes imbibe plant carbohydrates for synthesis of energy reserves and blood for reproduction and (2) egg production is reduced when mosquitoes feed on human blood compared with blood from other species. Sub-optimal amounts of the amino acid isoleucine in human blood (particularly free isoleucine in plasma) are thought to be responsible for lowered egg production when human blood is ingested. We tested the hypothesis that feeding on human blood is associated with a selective advantage for Ae. aegypti and is an underlying reason for this mosquito's intimate and epidemiologically important relationship with human beings. Our five experiments examined the effects of different isoleucine concentrations on accumulated energy reserves, frequency of host contact, survival, and egg production. When mosquitoes imbibed blood meals over a 7- to 10-d period and were not fed sugar, increased isoleucine concentration decreased energy reserves and did not increase egg production. Aedes aegypti took smaller but more frequent blood meals when feeding on a low-isoleucine human host daily compared with a high-isoleucine mouse host. Previous reports that isoleucine enhances egg production were confirmed only when females were fed sugar, an unusual behavior for most domestic Ae. aegypti populations. Females fed human blood and water had greater age-specific survival (l(x)), reproductive output (m(x)), and cumulative net replacement (R0) than cohorts fed human blood plus sugar or isoleucine-rich mouse blood with or without access to sugar. The unique isoleucine concentration of human blood is associated with Ae. aegypti's unusual propensity to feed preferentially and frequently on humans--a behavior that increases this mosquito's fitness, synthesis of energy reserves, and contact with human hosts, making it an especially effective disseminator of human pathogens.

The greatest advances of climatology are destined to lie in the border field of biology provided cooperative research becomes the trend in attacking future problems.

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