I think the house spiders take care of both. You know the type that hang out in the corners of your house. I've got a few living around my plants and have no problems. I've seen the fruit flies or knats or what ever they are flying around and in the spider webs being eaten for lunch. So think again before you smash that itsy bitsy spider, try scooping it up and dropping it in your greenhouse or around your plants! I'm not talking spider mites, I'm talking actual spiders.
