by Emil Morhardt
As a follow-on to the previous post, this paper was just published a week ago and makes it clear that all the targets of Asian Tiger Mosquitos—transmitters of dengue, La Crosse, and chikungunya viruses in the Northeastern US—are mammals, and most of them are humans, cats, and dogs. Humans were targeted more in the suburbs, and cats in the cities. This is quite different from Culex mosquitos, another major vector of human diseases, which primarily feed on birds. Ari Faraji and his coauthors found this out by trapping mosquitos in central New Jersey, then sequencing the DNA in their blood meals. Mammalian blood constituted 84% of the meals, with humans making up 52%, cats 21%, and dog 12%. The rest came from mammals also, including, opossums, squirrels, rabbits, and deer.
Central New Jersey is at the northern limit of these mosquitos at the moment, but climate change is expected to allow them to expand their range to all US urban centers (where they thrive), spreading diseases from person to person, and from other animal species to people. If their absolute preference for mammals found in this study is generally true, they will not spread West Nile Virus, which needs an avian intermediary, but that is small comfort since they may be even better vectors of dengue and chikungunya viruses than if they fed on birds.
The probable reason that humans are the primary target in the suburbs is outdoor activities in the evening when the mosquitos are feeding. In the inner cities, large numbers of feral cats, and dogs that are caged outdoors may be more available, decreasing the chances of mosquito-driven urban human epidemics, but not in the suburbs. According to the authors, this species of mosquito is quite difficult to control, so the problem is clearly something else to worry about.
Faraji, A., Egizi, A., Fonseca, D.M., Unlu, I., Crepeau, T., Healy, S.P., Gaugler, R., 2014. Comparative Host Feeding Patterns of the Asian Tiger Mosquito, Aedes albopictus, in Urban and Suburban Northeastern USA and Implications for Disease Transmission. PLoS neglected tropical diseases 8, e3037.
Full paper at http://bit.ly/1nOTjun