Scientists have found the causes of aggression mosquitoes
Researchers at Princeton University have solved the mystery casaceli mosquitoes – their aggression against people due to global warming and urbanization, evidence published Thursday in the journal Current Biology finding.
The research noticed that only a few of the more than 3.5 thousand species of mosquitoes bite humans and become dangerous carriers of infectious diseases. Scientists have tried to answer the question of what provokes the individual members of the species to be more aggressive to people than their congeners. According to the published study, scientists have identified two main factors – climate change and the urban environment.
The study concerns aegypti mosquito (Aedes aegypti), which are the main carriers of the virus SYKE, dengue fever, yellow fever and chikungunya virus. In their natural habitat, members of the family aegypti mosquitoes feed on both blood and other warm-blooded.
"Mosquitoes, living among a large number of people in the cities of Kumasi (Ghana) or Ouagadougou (Burkina Faso), demonstrate increased desire to bite people. But their greater appetite to people only occurs in areas with intense dry seasons, especially in the Sahel, where rains are only a couple of months in a year. We think this is due to the fact that in such climates mosquitoes in their life cycle are particularly dependent on people and man-made water reserves," - said study author Noah rose.
The scientists ' conclusions are confirmed by them experience: collecting mosquito eggs in 27 different places in the region South of the Sahara desert, the researchers at the lab tried to find out food preferences born of mosquito larvae by offering them the smell of people or animals, for example Guinea pigs and quails. It turned out that those insects that were collected in densely populated areas, were more likely to choose human sacrifice than those of their relatives that lived in villages and desert areas. In addition, it was found that mosquitoes living in areas where the dry season longer and more severe, more responsive to the smell, so the blood of humans, rather than animals.
It is noteworthy that climatic peculiarities have in this matter is crucial, experts say: "it was surprising to find that the climate was more important than urbanization for explaining existing behavioural changes in insects. "Many mosquitoes living in relatively densely populated areas people do not necessarily prefer biting people," said rose. His colleague and co-author Lindy McBride emphasizes that "only if cities are very densely populated or located in areas with more intense dry seasons, mosquitoes are becoming more interested in biting people".
Based on these findings, the researchers suggest that growing urbanization in the coming decades will mean a greater number of mosquitoes biting people in the future. "Rapid urbanization could trigger an even greater number of mosquitoes biting people in many cities South of the Sahara in the next 30 years," notes rose.