This annoying white fly/moth seems to have infested my three indoor worm bins and a large outdoor bin. They appeared after bringing a load of my outdoor bin's contents indoors into a bin. As I am a worm seller on Vancouver Island, I'm concerned about passing on this pest. My local compost education centre advised putting the bins outside for a day with the lid off. Seemed to work but flies have reappeared. Also advised to covered the soil with an inch of shredded paper and a burlap cover. That didn't work. I have killed all I can catch. I also hung a bright yellow strip covered with petroleum jelly, but only one fly was stupid enough to get stuck to it. Any thoughts? Was hard to photograph but hopefully you get the idea. They are about 3mm long. Thanks for any thoughts you may have. Does not appear to be a whitefly, based on the shape of the wings.
Hello - do you know of Dr. Linda Gilkeson, an entomologist and garden authority who lives on Salt Spring Island? She will often answer garden questions like yours. You can find her at: Linda Gilkeson || West Coast Gardening || Organic Year Round Gardening
Thank you Margot! Linda informs me that they are sewer gnats (also called drain flies, sink flies, filter flies, moth flies). She suggested sticky traps, but as this didn't work, I'm going to try a trap made of a bowl of equal parts vinegar, water, sugar with some drops of dish detergent on top. Sounds like they can be very tricky to eradicate as they like moist environments.
I just remembered something I heard about a long time ago that may or may not help at least lower the numbers of flies; something I've never tried myself. That is to use a small, handheld vacuum cleaner to suck up the insects that are flying around. That doesn't get rid of those still unhatched but maybe over time you'd knock them back, together with your trap and whatever other strategies you might come up with. Good luck!
Thanks for the tip Margot. They are actually very easy to catch by hand, so I kill about 20 of them at a time, but it doesn't stop new flies from hatching. This fellow on Youtube seems to have found a solution using reemay cloth, a.k.a. row cover.