Researchers from Ohio University (USA) have shown in a study that the Light pollutionthat is, the excess of artificial light occurring in urban environments at night changes the bite season. mosquitoesmake it longer and longer.
Work published in the journal Verminexplores how artificial light at night affects circadian activity (the physical, mental, and behavioral changes that living things undergo in a natural 24-hour cycle) and metabolic activity of the northern house mosquito. Culex pipids. This strain is precisely a carrier of the West Nile Virus.It transmits fever to both humans and horses after biting infected birds.
The state of artificial night light is perceived both in the accumulation of nutrients by this insect and in the onset of diapause, a stage of inactivity in which these animals plunge with the arrival of winter. This is a key stage in the survival of reproductive-age females when temperatures drop. That’s when they enter the state of sleep, where they seek refuge in caves, sewers, sheds, and other semi-protected places.
For this reason, diapause females avoid drinking vertebrate blood and feed on “nectar only”. According to the study, during the long night periods to guarantee survival during the winter months. Due to this, the bites are reduced.
Active and more time to snack
This cycle is naturally regulated by light, the signal by which species regulate their biological processes not only daily but also seasonally. By adding artificial light, these processes change seasonal metabolic differences. delay or postpone, Culex penises the onset of diapause, which implies that they are more active and therefore bite.
“The highest levels of West Nile virus transmission are seen in Ohio in late summer and early fall. If there are mosquitoes that delay or delay diapause and remain active longer of the year, then mosquitoes are more likely to be infected with West Nile virus and people may be at higher risk of contracting itor,” says Megan Meuti, lead author of the study and assistant professor of entomology at Ohio State University.
In addition to the risk posed by the prolongation of these mosquitoes’ biting seasons and the accompanying increase in fall West Nile virus transmission in urban areas, this change could put survival at risk, the researchers stress. These mosquitoes in winter
“In mosquitoes reared on short days, exposure to artificial night light slightly increased daily activity levels and was associated with greater variability in lipid stores, whereas in mosquitoes reared on long days, artificial night light suppressed lipid accumulation of glycogen and water-soluble carbohydrates,” concludes the study.
This isn’t the first research to show how artificial light promotes the spread of certain mosquito species.
According to Álex Richter-Boix, a biologist with the Mosquito Alert program (a citizen science project), the effects vary between mosquito species. For example, yellow fever mosquito (aedes aegypti) Increases the bite rate when there are lights in the middle. 50 lux incandescent. mosquitoes (Culex penises) prolong their seasonality in artificially lit areas: They bite and reproduce later in the mosquito season, thus prolonging the disease risk period in urban environments.
Artificial light reduces diapause by 40%. HE tiger mosquito (Aedes albopictus), also extend the operating time. In contrast, mosquitoes anophelesThe effects involved in the transmission of malaria appear to be opposite, especially when it comes to ultraviolet light: artificial light suppresses their activity.
Reference work: https://www.mdpi.com/2075-4450/14/1/64
……..
Contact address of the environment department: [email protected]