I use fly strips in my greenhouse and they work great. I also transplanted a couple of orb weaver spiders into there and even the fly strips are looking bare now. Their web locations can get annoying but they're always quick to rebuild if torn down-- spider, whom are web weavers, are perfect. Of course if it's not an enclosed area they'll probably just leave. I've also heard of people putting a thin layer of sand on top of the soil since the larvae grow out of the soil, but I haven't used this method. Good luck to you.