As deforestation and habitat loss drive down wildlife populations, mosquitoes are increasingly turning to another source for their blood meal: humans. That’s the finding of a new study in Brazil’s Atlantic Forest, a global biodiversity hotspot with less than a third of its original forest remaining. Mosquitoes in the Atlantic Forest “have a clear preference for feeding on humans,” senior author Jeronimo Alencar, a biologist at the Oswaldo Cruz Institute in Rio de Janeiro, said in a statement. To reach that conclusion, researchers collected 1,714 mosquitoes from two different Atlantic Forest reserves in the Brazilian state of Rio de Janeiro. Only female mosquitoes bite; they require a blood meal to develop their eggs, so researchers focused on the 145 engorged female mosquitoes they collected. Of those, just 24 contained blood that could be successfully analyzed and matched to known vertebrates using DNA analysis. Three-quarters of the samples, 18 of the 24, revealed that the mosquitoes had fed on humans. The other sources of blood came from six birds, one amphibian, one canid and a mouse. Several mosquitoes had fed on more than one host species, including combinations of human/amphibian and human/bird, further raising concerns about the spread of disease. Researchers say they believe mosquitoes are showing a preference for human blood because deforestation and habitat loss have reduced the number of wild animals available for mosquitoes to feed on. “Once the vertebrate population decreases, moving for other habitats, mosquitoes … go in search of new blood sources,” Sérgio Lisboa Machado,…This article was originally published on Mongabay

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