I'm wondering if blue LEDs will draw flys to a sticky trap. I seem to have a problem with them lately. What do you guys think?

FWIW It has been my observation that common flies (i.e, musca domestica) are only sparingly phototropic --- Chemical attractants are likely a better, and, unfortunately, rather odoriferous choice...

Best Regards
HP

 

If the fly is persistent, i.e. longer than 30 days, I would identify and study the fly.

This takes no effort now.

Find a point in his environment that doesn't disturb you or your property.

Sometimes this is less time consuming than culling what the environment can provide.

It's a gamble.

One of the possible outcomes is.........you might provide an environment for a superior pest.

 

On the subject of fly traps, there's a huge spider living in the track of a vinyl window frame for my living room.

It built a large triangular web on the outside of the window and it hides in the track until something comes along. At least two flies have wandered too close and have been trapped. Then the spider runs out from the track and snatches the prey for lunch, dinner, or a snack.

These spiders are probably not hazardous to humans and if I could get a few more of them to build a web, it makes an environmentally friendly insecticide.

Take up cycling - or even walking.

Spiders trail out a strand on breezy days to snag any passing humans. once they catch one, they reel themselves in and hitch a ride to their new home.