Sound-seeking Flies?

[Oldstick]

I guess I don't do this kind of work all that often, at least not during August and never experienced this before.

I was using a circular saw today in the back yard. Late morning, approaching noon and the heat was already building up good. The instant the teeth started engaging and the high pitched scream started, these big black flies would converge on me. On the saw, on my arms, on the material very close to the blade even. Distracting enough, that I had to stop immediately and re-focus for safety sake. First I thought they were horse flies, but too small for that. They were black and about 2 or 3 times the size of a house fly. As soon as the saw stopped they disappeared.

The only credible sounding idea I found on google, was a certain fly that is a parasite and seeks cicadas to lay their eggs on (or in, not sure which). Apparently they use the sound to hunt down the cicadas. Made sense to me, in that the pitch of the saw blade scream is certainly similar to cicadas.

Probably something very common to a lot of you folks, but certainly a new one for me.

 

[greg j]

I have had heard about that before. I think you are right that they are attracted by the sound and looking for a cicadas.

 

[Oldstick]

I have had heard about that before. I think you are right that they are attracted by the sound and looking for a cicadas.

Evidently, not as common as I had assumed, but my OP was an absolutely true account of what occurred a couple days ago.

Another detail. The material I was cutting with the 7.25 in skill saw was flooring planks with some concrete based material in the center. So it was a really high, high, and extra high pitched sound from the saw. Similar to a circular blade cutting metal or tile.

Way up there with the same pitch as cicadas singing. So I must have been the loudest and most powerful nest of cicadas around my neighborhood.

 

[fi8shmasty]

They always do that. I think they are cacadis. They don't hurt anything.
The sound or vibration gets them coming. I guess they think it's time to mate or something.

 

[fireman32]

I’ve had it happen. I’ve had bees and wasps come check out my saw and an orbital sander too.

 

[mguthrie]

I use a circular saw nearly every day outside and I’ve never had this happen. I’m cutting mostly pine and fir though. Maybe not the same frequency that your talking about. Pretty odd though to be attacked by flies.

 

[Southernbreeze]

A few weeks ago I was putting a new sink in my house and I had to cut the granite countertops to get it to fit. I opened the doors and windows to help draw the dust it created outside. When I was cutting, the sound was very high pitched. When I finished It seemed like every fly in the county was drawn to that saw.

 

[Oldstick]

Bumping this one up, because it happened again today. I was outside with a cheap wet tile saw. Cutting a few of the final pieces for a flooring project we started 3 months ago.

August and the Cicadas are out and sounding off this month fore sure. And low and behold, here came the mini-sized "horse flies" landing on my saw every time I started cutting. Been cutting in May, June and July and only noticed it when I got around to the finishing touches today.

So my money is on the internet theory of whatever species of fly seeking Cicadas to lay their eggs inside.