Is it true that mosquitoes do not bite persons under alcoholic influence?

V. USHA

Uthagamandalam, Tamil Nadu

It is not true that mosquitoes do not bite persons under alcoholic influence. Rather, alcohol consumption increases the risks to mosquito bites.

In general, female mosquitoes suck the blood from humans and animals since they require the blood meal for protein to make their eggs. They are mostly active during the dawn and dusk. However, species like Aedes are also active during the day time. Environmental factors including heat and moisture, and olfactory cues including carbon dioxide attract mosquitoes towards their hosts.

Although it was believed for a long time that humans suffer from more mosquito bites after ingesting liquor, it was confirmed in the recent years by conducting proper research experiments. A study published in 2002 revealed that mosquito bites significantly increased for those who ingested beer containing an ethanol concentration of 5.5 per cent. It seems that drinking alcohol makes people three to four times more attractive to biting mosquitoes. Another study published in 2011 showed that mosquitoes are 15 per cent more likely to approach people who have consumed alcohol. Thus it is quite clear that drinking alcohol stimulates mosquito attraction.

It is hypothesized that the changes in the odours and other cues due to the metabolism of alcohol may be responsible for the attraction of mosquitoes. However the exact reasons are not yet clear, since the researchers found no correlation between the ethanol content in sweat and skin temperature after alcohol ingestion and mosquito landings. Thus, persons under alcoholic influence are more prone to mosquito bites.

Dr. R. SRINIVASAN

Entomologist and Head of Entomology Group

AVRDC -The World Vegetable Center

Tainan, Taiwan

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