(ORDO NEWS) — Researchers at Princeton University have uncovered the mystery of mosquito biting – their aggression against humans is driven by global warming and urbanization, according to a study published Thursday in Current Biology.
The authors of the scientific work drew attention to the fact that only a few of the more than 3.5 thousand species of mosquitoes bite people and become dangerous carriers of infectious diseases. Scientists have tried to answer the question of what provokes certain members of the species to be more aggressive towards people than their relatives. According to the published study, scientists have identified two main factors – climate change and the urban environment.
The study concerns yellow fever mosquitoes (Aedes aegypti), which are the main vectors of Zika virus, dengue fever, yellow fever and chikungunya virus. In their natural habitat, representatives of the yellow fever mosquito family feed on both the blood of humans and other warm-blooded animals.
“Mosquitoes that live among large numbers of people in the cities of Kumasi (Ghana) or Ouagadougou (Burkina Faso) show an increased desire to bite people. It only rains for a couple of months a year, and we think this is due to the fact that in these climates mosquitoes are especially dependent on humans and man-made water supplies for their life cycle,” said study author Noah Rose.
The scientists’ findings are supported by their experience: collecting mosquito eggs in 27 different places in the region south of the Sahara desert, researchers in the laboratory tried to find out the gastronomic preferences of mosquitoes born from larvae, offering them the smells of people or animals, such as guinea pigs and quails. It turned out that those insects that were collected in densely populated areas were more likely to choose human prey than those of their relatives that lived in villages or even more uninhabited areas. In addition, it turned out that mosquitoes living in areas where the dry season is longer and more severe are more responsive to the smell, which means the blood of people than animals.
Notably, it is climatic conditions that are critical, experts say: “It was surprising to find that climate was more important than urbanization in explaining current insect behavioral changes.” Many mosquitoes living in relatively densely populated areas are not necessarily prefer biting people, “notes Rose. His colleague and co-author Lindy McBride emphasizes that” it is only if cities become very densely populated or in areas with more intense dry seasons that mosquitoes become more interested in biting people.
Based on these findings, scientists suggest that increasing urbanization in the coming decades will mean even more human-biting mosquitoes in the future. “Rapid urbanization could cause more mosquitoes to bite people in many sub-Saharan cities over the next 30 years,” Rose said.
Contact us: [email protected]