I've noticed that my indoor plants on the window sill are overrun with tiny flies, and I'm wondering if introducing spiders could help get rid of them. Has anyone tried this before on their houseplants? Should I look for spider eggs or is there a better option?
4 Answers
I’ve heard that while spiders aren’t the best option, predatory mites can help with some pests. I usually stick with sticky traps for fungus gnats. Just put them around your plants, and they can really cut down on the pesky flies!
It sounds like you're dealing with fungus gnats! Instead of spiders, you could use nematodes in the soil to eliminate the larvae and eggs. They do wonders and in just a few days, you could be free of gnats!
Have you thought about using Bacillus thuringiensis israelensis? It’s effective against gnats and works well with mosquito dunks or gnatrol. Those, along with some nematodes, should do the trick!
Before you go for spiders, make sure to identify the flies. If they are indeed fungus gnats, there are some simple things you can do to cut down their numbers. Reducing watering often helps; dry soil can kill off the larvae.

Thanks for the tip! I’ll definitely consider the sticky traps.