Midge flies invade Southwest Florida; could be sign of poor water quality

Pesky midge flies have invaded Southwest Florida. Many viewers have reached out to us wondering what they are and why they’re showing up.

“They are non-biting flies; they are not going to bite you or hurt you but they are a nuisance and frequently you see them around sewage treatment areas,” said Jonh Cassani, Calusa Waterkeeper.

He says they’re a symptom of poor water quality.

“The nutrients in the other pollutants build up over time and they produce sort of these organic sediments; bacteria need oxygen to decompose the organic matter in the sediments,” he said. “That is what drives the oxygen level down and makes it a good environment for the midges to live in.”

What can we do to make sure another swarm like this doesn’t happen again? Cassani says the key is to improve water quality around us. But, the damage has already been done.

“Turning back the clock on cumulative effects of nutrient pollution is pretty hard,” Cassani said.

He believes temporary relief is coming. Soon, they’ll be dropping like the flies they are and you’ll see more piles to sweep into the trash.

But as long as the water quality is poor, these flies will keep lurking beneath the surface.

“These insect populations are responding to changing conditions through time, and just like red tide, we are seeing more nutrients in the back bays and nearshore areas, and what happens? It makes the red tide last longer,” Cassani said.

There are, fortunately, a few ways to manage the ones around your home or outside your door. Cassani says, if possible, don’t use a killer bug spray and, if you own a power washer, use it as soon as possible.