Mosquitoes may not bite indiscriminately
hugh sturrock/Alamy
Hedonists who drink beer, don’t wash, share a bed and eschew sunscreen may be more attractive to mosquitoes – at least, that’s what a study of festivalgoers found.
For their Mosquito Magnet Trial, Sara Lynn Blanken at Radboud University Medical Centre in the Netherlands and her colleagues visited the 2023 Lowlands Festival, near Amsterdam. They asked 465 attendees to complete a questionnaire about their health, diet, hygiene, sunscreen application, any substance use, blood type and whether they had slept alone the night before.
The team also set up a makeshift laboratory in shipping containers, containing 1700 captive-reared mosquitoes (Anopheles stephensi), which can transmit malaria.
Between 20 and 35 mosquitoes were put into a series of clear plastic containers with a perforated divider separating the participants’ arms from the insects, so they could attempt to land on the revellers, but not actually bite them.
The researchers counted how many times the mosquitoes tried to land on the festivalgoers’ arms in three minutes compared with a decoy of cotton pads soaked in glucose.
“Mosquitoes showed a clear preference for the well-hydrated, on hops and grapes, that is,” according to the researchers. “Arm landings were significantly higher in beer drinkers compared [with] those who had nobly abstained for at least 12 hours.”
Blanken says she won’t let this put her off beer. “I would just wear long sleeves and insect repellent,” she says.
The researchers also found that the “participants that successfully lured a fellow human into their tent the previous night also proved more enticing to mosquitoes”. Sunscreen seemed to repel the mosquitoes, possibly by masking skin smell or acting as a repellent. The researchers found no evidence that different blood types attract or repel the pests.
“We found that mosquitoes are drawn to those who avoid sunscreen, drink beer and share their bed,” according to the team. “They simply have a taste for the hedonists among us.”
Festivalgoers put their arm through a partition where mosquitoes could try to land on them, but not actually do it
Lowlands festival/Nationale Wetenschapsagenda Netherlands
Cameron Webb at the University of Sydney says it’s a fun study that he wished he’d thought of, but it included only one species of mosquito, and the results would probably differ with other types.
The researchers also found that only four of the participants had zero attempted landings on their arms. “The biggest take-out message for me is that the vast majority of participants, irrespective of all the other factors considered, attracted mosquitoes looking for a blood meal,” says Webb. “The reality is that if we just reminded ourselves to put on mosquito repellent and spent less time thinking about why mosquitoes bite us, we’d all probably receive fewer bites and lower our risk of mosquito-borne disease.”
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