Question
I live in South western Montana close to the Bridger Mountains. I have been getting these small spiders on my plants. The spider is black with white spots and is about the size of a jumping spider. It doesn't crawl very fast and it doesn't "jump". Also, when I've squished them they feel like any normal spider would, not a super hard shell but it does have a "crunch". It creates a wed around the top of the plant and has little black "deposits" in it which I assume are eggs or feces. For each web I find at least one spider sometimes two but no more than that. I have searched the plants for other bugs and can't find anything. There also have been no bugs in the webs for the spiders to eat. I had an Aspen and just let them live on it. The tree is now dead. They are now on my lilies. I have about ten lilies in a planter, three are infected and have started to turn yellow. The other flowers are still doing well and have no webs. I have searched my property and can not find any other places these live except for on the plants. I took one of these spiders to a local tree nursery and they had no idea what it is. My mother, who lives in the same town, has gotten them before and all of the plants they were on died. What are these pests and how do I get rid of them? I've tried physically picking them off and killing them and spraying them in a solution of lukewarm soapy water nothing has worked! I'd appreciate your input! Thank you!

Answer
Brenna,

If these really are spiders they are not the cause of the plant problems because all spiders are predators, they don't feed on plants. In fact the spiders are probably protecting the plants from other plant pests by preying on the pests. If you post a picture of the spider and the plant damage I may be able to tell you a little more about what may be going on.

Jack DeAngelis, PhD
Extension Entomologist (ret.)
My website about home and garden pests: http://www.livingwithbugs.com