Q • We have a large knockout rose bush in the front yard. This spring, I noticed there was a section with lighter-colored green leaves than the rest of the bush. I later saw two separate “webs,” like those bagworm webs, in the middle interior, and lots of dying branches around them. I removed them and saw little brown bugs in them. I have never done any spraying or any other maintenance for this bush, and that’s why I like knockout roses so much.
A • I can’t be certain without actually seeing what you’re describing, but your description reminds me of the messy webs of tangleweb spiders (Anelosimus studiosus). Also known as social cobweb spiders, they are curious, tiny spiders that basically live communally with their sisters inside of a sticky web that catches and envelops debris that falls onto the web surface. The interior of the web also becomes filled with the spent bodies of insects that the spiders have consumed.
These webs are often found at the tips of branches, rather than the interior of the bush. Here is a link to an image of a tangleweb on a holly tree bugguide.net/node/view/1182745/bgpage.
I don’t recommend spraying beneficial spiders. My recommendation is that you just prune off the web and dispose of it.