'Fly Season' is rampant ahead of upcoming hibernation

Posted at 6:33 PM, Sep 18, 2023

BOISE, Idaho — If you've been outside in the past few weeks you might've noticed an increase in flies, whether you're outside eating a meal to they're trapped inside of your house.

The weather is cooler and more people are sitting outside enjoying their meals, but while you're sitting outside you might not be the only one getting a bite of that tasty dish.

"Yesterday I was getting a carwash and I had like 40 come into my car while I was vacuuming it was ridiculous,” says Kylie Morris

Jared Huber says, “I mean not even down here specifically but, in the Village, there's been more flies in the last year or two years than I've ever seen.”

Most can agree that flies can be a little annoying but in the past several weeks here in the Treasure Valley, we've seen an increase in them. But why?

“There are a lot of different kinds of flies but the ones you're noticing are house flies and blow flies because they eat dead animal material and plant material,” says Paul Castrovillo.

Paul Castrovillo is the former entomologist for the Idaho Department of Agriculture. Now he’s an insect curator and research associate at the Orma J. Smith Museum of Natural History at the College of Western Idaho Caldwell.

In the winter these flies are hibernating, they come out in March.

But it's not until summer that you begin to notice them and that's because of reproduction and they’re looking for food and it's towards September they're at their worst.

Castrovillo says, “The flies are deciding to hibernate because the days are getting shorter or flying around until the frost hits and they die. So now we're at the point where there are the most flies that are going to be for the whole season.”

Although right now isn't the best for flies, most people want to sit outside and enjoy their meal.

Flies are attracted to dead animals so to us our delicious burger also looks delicious to flies and so restaurants like Matador on 8th Street have to accommodate.

“Mostly we see them on the patio which is kind of hard cause 8th street is a good place to eat on the patio a lot of people watching, and we also invested in these little fly spinners that have a reflective ribbon that deter flies I guess,” Jyllian Ahart, Bar Manager at Matador.

Flies can be annoying, but like almost any insect they're important to the environment, so whether you're at a restaurant or walking outside your best way to get rid of them is of course swatting them away.