Warning: If you are going to gorge on your food it could ruin your meal. Did you know that when flies land on food to eat it, they vomit on it first?
This vomit contains traces of what they ate previously, whether it was a piece of someone else’s dinner or something much less spicy, such as dog poo.
Now scientists warn that we should be more alert to the dangers of the common housefly and its vomit on our food.
Researchers at the University of Massachusetts Amherst looked at the dangers of “synanthropic” flies, common flies that do not bite us and live with us.
They say that while research has focused mainly on biting flies such as mosquitoes as harbingers of disease, spreading it by transferring infected blood from host to host, these synanthropic flies can pose an even greater threat.
“I’ve been working on synanthropic flies since I finished my master’s degree in the 1960s.” Said John Stoffolano, professor of entomology at UMass Amherst’s Stockbridge School of Agriculture, who is the author of the study published in the journal Insects.
“And the synanthropic flies have been largely ignored. Blood-sucking flies are in the spotlight, but we should pay attention to those that live among us, because they get their nutrients from humans and animals, which excrete pathogens in their tears, faeces and wounds. ” .
What do flies eat before they land on your food?
He explained that the common housefly flies around, nibbling on different types of highly unpalatable food, which can include things like death in the road, pile of animals, rotting garbage, and sewage water.
When it eats, it fills up its crops – which Stoffolano said “it’s like a gas tank” – but it’s a place for storage, not for digestion, so there are few digestive enzymes that would normally destroy most pathogens.
The crop is “a place where food is stored before it enters the digestive tract, where it will be converted into energy for the fly,” he said.
When a fly wants to eat a new piece of food, it releases liquid from its crop onto the surface of the food as part of the eating process.
According to Stoffolano, because of the nasty stuff flies accumulate in their crops, they could accidentally become a storage place for pathogens.
Worse still, cultivation is also where microbes develop resistance to bacteria, which could spell disaster for people infected with the pathogen.
“It’s the little things that cause problems,” says Stoffolano. “Our health depends on paying more attention to these flies that live with us.”
The authors of the paper warn that the area requires “a lot of targeted research” because currently not enough is known about the importance of flies in the spread of disease and potential microbial resistant microbes.