PHILADELPHIA (KYW Newsradio) — Chester County residents and farmers alike are growing impatient with a surge of tiny flies that are feeding on networks of mushrooms grown in the area and invading people’s homes.
About half of the mushrooms grown in the U.S. come from Kennett Square. Like any crop, dealing with pests is an ongoing battle. However, farmers have fewer tools available to keep these bugs, known as phorid flies, at bay due to environmental regulations.
“Most of the chemicals that were used to fight disease and pests like the phorid fly have been banned, so naturally the population of the phorid fly has increased,” said one mushroom farmer, who asked not to be identified.
“It’s not really that the square footage of mushrooms being grown has increased in the area,” he added. “A lot of small farms have gone out of business, but there’s nothing to deter that fly.”
He said the flies are noticeably worse this year, invading residences in Chester County and neighboring towns as well. Dr. Christopher Tipping, chair of the Department of Biology at Delaware Valley University, said the flies live in the manure piles used to grow mushrooms.
“Mycelia grows all through those pits,” he explained. “That’s where those larvae live … and those numbers can increase pretty quickly. It’s ideal conditions for them. And then they often escape out of the house.”
Residents struggling with phorid flies in their homes can try using a plug-in bug catcher to determine how severe the infestation is, Tipping said.