21/05/2026

LYFE THURSDAY | MAY 21, 2026

FOLLOW

ON FACEBOOK

24

Malaysian Paper

/thesundaily /

E VER felt like mosquitoes bite you while ignoring everyone else? Scientists are now making progress in deciphering the complex chemical cocktail that makes particular people more enticing to these disease spreading bloodsuckers. “It’s not a misconception – mosquitoes are attracted to some people more than others. But we are not all magnets all the time,” Frederic Simard of France’s Development Research Institute told AFP. A range of sensory cues can cause mosquitoes to pick one human over another – mainly the smell and heat our bodies give off and the carbon dioxide we exhale. Female mosquitoes – which are the only ones that bite – detect these signals with finely-tuned receptors, then choose their target accordingly. “We have known for over 100 years mosquitoes are attracted by the carbon dioxide that we exhale – this is the first signal that triggers their behaviour” when they are dozens of metres away, Swedish scientist Rickard Ignell said. Within around 10m, “mosquitoes will start detecting our odour and in combination with carbon dioxide” and this attracts them even more, said the senior author of a recent study on the subject. As they get closer, body temperature and humidity make particular humans even more enticing. Blood type does not matter However some popular theories on this subject do not hold water. The idea mosquitoes prefer particular blood types “has no scientific basis. “There have been some studies but only involving very few people. Nor is it related to skin, eye or hair colour,” Simard said. Odour, on the other hand, matters greatly. “A soup of molecules produced by our microbiota is more – or less – WHEN a mosquito tries to bite biology professor David Inouye during fieldwork among orchids in Colorado, he pauses before swatting the bug. If it is dusted with pollen, he lets it live. “I give those mosquitoes a pass to help the orchids,” Inouye said. Mosquitoes are better known as bloodsuckers that spread malaria, dengue and other diseases but at least some also play a little-known role as pollinators. Nocturnal nectar feeders There are more than 3,500 types of mosquitoes buzzing around the world, but only around 100 bite humans. Only the females are out for blood, targeting humans and animals for protein they require to produce eggs. But male and female mosquitoes need to feed on the sugar and nectar from plants and flowers. Yet their role in flower reproduction is far less studied than that of bees or butterflies. “Part of it might be that many mosquitoes are either nocturnal or active at dusk or at dawn. “So it’s a little less convenient to study them than it is to study bees

What mosquitoes crave most

A cloud of mosquitoes flies near a wetland in Donana National Park in southern Spain following recent rains.

o Some people attract bloodsuckers more than others, research explains why

A laboratory technician holds a mosquito at the World Mosquito Programme factory in Medellin, Colombia.

that are flying in the middle of the day or butterflies that are only active when the weather is nice,” Inouye, a Maryland University professor emeritus based in Colorado told AFP. Another reason their part in pollination is under-studied could be because scientists are more focused on the mosquitoes’ role as carriers of diseases, said Lawrence Reeves, a Florida University entomologist. “I think this is both a problem in science – among those who study mosquitoes and just among the general public – that potential role is really just overshadowed by their role in vectoring disease. “If we consider mosquitoes are one of the relatively few kind of specialists of nectar and other plant sugars as their food source, we can kind of use that to calibrate what our expectation might be for their potential role as pollinators,” he said. Scientific debate The extent of their role as pollinators, however, is a topic of debate in the scientific community. “There are two camps in the scientific world. One supports the idea that mosquitoes play an important role in pollination, the other believes mosquitoes are appealing to mosquitoes,” Simard explained. Humans release between 300 and 1,000 different odorous compounds, research has shown, but scientists are only just beginning to understand which ones attract mosquitoes. For Ignell’s recent study, the researchers released Aedes aegypti mosquitoes – known for spreading yellow fever and dengue – on 42 women in a lab to see which ones they preferred. “We have shown mosquitoes use a blend of odorous compounds (we identified 27 the mosquitoes will detect, out of the possible 1,000) for their attraction to us,” Ignell said. The woman the mosquitoes most liked to bite – which included

pregnant women in their second trimester – produced a large amount of a particular compound made by a breakdown of the skin oil sebum. That even a small increase of this compound – called “1-octen-3-ol” or mushroom alcohol – made a difference came as a surprise, Ignell emphasised. “Mosquitoes are fascinating creatures,” he added. Beer makes you attractive Drinking beer has also been linked to attracting mosquitoes because it raises body temperature, increases the amount of exhaled carbon dioxide and changes skin odour,

becoming a more pressing issue as climate change expands the range where they roam. For example, the tiger mosquito, a vector for the chikungunya virus, is spreading into new areas. Last year, chikungunya reached as far north as France’s Alsace region for the first time. “This risk is affecting more and more people,” Simard said. So what can you do to avoid getting bitten? Try loose-fitting clothing that covers your skin, mosquito nets and repellent, Simard advised. “Try to eat light meals – and go easy on the alcohol,” he added.

according to several studies. For standardised research conducted in Burkina Faso, some brave volunteers drank beer, then several days later water, to see which mosquitoes preferred. The Anopheles mosquito, which can spread malaria, was more enticed by the scent of the beer drinkers. For a 2023 study in the Netherlands, 465 volunteers put their arms in cages filled with female Anopheles mosquitoes. The volunteers who had drunk beer in the previous 24 hours were 1.35 times more attractive to the mosquitoes. Discovering why mosquitoes prefer particular people has

Pesky pests may also be flower lovers, say scientists

A mosquito feeds on nectar from a milkweed in the Ouachita Mountains, Arkansas. – ALL PICS FROM AFP

‘Minor’ pollinators Inouye has spotted mosquitoes covered in pollen from Platanthera obtusata orchids at his field site, the Rocky Mountain Biological Laboratory. He has compiled a list of 76 mosquito species that have been recorded in papers as visiting flowers. “I think it is pretty incontrovertible that there is at least some role of mosquitoes as pollinator,” Inouye said. While that role is “relatively minor” compared to bees or butterflies, their relationship with flowers should be further studied, he said. “If it turns out they are significant pollinators of more than that one orchid species, then that might influence people’s decision whether they should pursue programmes of mass eradication of mosquitoes.”

which is widely considered one of the deadliest animals on Earth as it is known to transmit dengue and yellow fever. “After spending 10 years studying various plant and mosquito systems, I am convinced mosquitoes play a more important role in ecosystems than we realise and participate in the pollination of many plants,” Lahondere. She said she has two papers in progress focusing on two invasive mosquito species in US and Europe, including the tiger mosquito, showing both pollinate native plants with which they did not co-evolve. “This demonstrates how easily mosquitoes adapt in the presence of new sugar resources,” Lahondere said.

primarily nectar thieves and very rarely provide any benefit to plants,” said Chloe Lahondere, a mosquito expert and associate professor at Virginia Tech university in the US. Lahondere led a 2019 study which found Aedes mosquitoes are attracted by the scent of a type of orchid in the northwestern US state of Washington, sipping on their nectar and transferring pollen between the flowers. “The association between the Platanthera obtusata orchid and Aedes mosquitoes is one of the few examples that shows mosquitoes as effective pollinators,” said the study published in the Proceedings of the National Academy of Sciences . The study said those mosquitoes include the Aedes aegypti species,