Shoo, fly — indeed.
Houseflies may pose a greater risk to human health than originally thought, according to new research.
Scientists at the University of Massachusetts Amherst have warned that seemingly innocuous — albeit annoying — common flies could actually be carrying disease-producing pathogens and transmit them to humans by means of “fly vomit.”
Entomologist John Stoffolano suggested that non-biting, synanthropic flies — the ones buzzing around dumpsters and dog poo — may pose a greater risk than mosquitoes and other blood-sucking insects.
“Blood-feeding flies have taken the limelight, but we should pay attention to the ones that live among us because they get their nutrients from people and animals that shed pathogens in their tears, feces and wounds,” said the UMass Amherst professor to Boston outlet WCVB.
While both male and female flies visit decaying carcasses, animal feces, food waste and other filth, it was revealed that female flies are more likely to visit carcasses, particularly while waiting to hatch their eggs.
The new study, published in the journal Insects, found that while their eggs are developing, females flies tend to land on diseased carcasses “more frequently” and create “more regurgitation/defecation” than males, as well as other females with eggs already primed for laying.
“Thus, females make better anal disseminators of pathogens and parasites,” authors wrote.
Scientists have long understood that flies vomit in order to make room for more food in their “crop.”
“The crop is like a gas tank,” Stoffolano explained. “A place to store food before it makes its way into the digestive tract.”
The fly then vomits excess water — and whatever illness-causing pathogens they carry — on whatever surface they landed on.
“It’s the little things that cause the problems. Our health depends on paying closer attention to these flies that live with us,” Stoffolano added.