I haven't seen this before. I did use dormant spray in February but this poor tree looks like it's been attacked by aphids and other things. Thanks for offering any ideas.
I can't see your bug in great detail but I suspect it is a ladybug (lady bird beetle, lady beetle) larva. In common parlance, the babies are as ugly as the adults are cute. If it is a ladybug, and if it is the first of many, your aphid problem may be history. Attached photo from: Ladybug - Gardening - College of Agriculture and Bioresources - University of Saskatchewan View attachment 167310 View attachment 167311
Hi Margot, thanks! I'm glad I didn't squish it then--I was sorely tempted to! It looks so different from the larvae that I saw elsewhere on the tree that I didn't really think it was related to a ladybug. There was a bit of a wind and I was having trouble holding the leaf with one hand while trying to hold my phone in the right place and press the shutter key with my little finger. Interesting info on the link; I normally rake up all of the leaves but we had our fence replaced last fall and I had several pots of raspberry canes that I rescued before they were knocked down by the fence crew, and there were a lot of leaves stuck between them, so this must be where the ladybugs wintered. Now I have an excuse to be lazy about raking! I wish I had joined this forum a long time ago, you people are wonderful!
So, I have an apple pear tree about 10 meters away from the plum tree. The aphids are much worse on the plum tree than on the apple pear, but there's rather a lot on the apple pear. If I carefully move a couple of ladybug larva that look like my profile picture over to the apple pear, do you think it's likely that I'll injure them, or should I just wait a week or two for them to migrate on their own? I'm thinking to take a curled, fallen leaf and try to blow the baby ladybug on to it, then push the leaf gently into a hotbed of aphids on the pear tree. The thing that has me confused is that these ladybug larvae that I'm finding are down further on the tree, not up at the top where it's crawling with aphids. How are they finding enough to eat? And then there's several larvae the in-between stage where they look like a mutant ladybug without wings, but they aren't moving at all--are they able to eat aphids during this stage? Ulp, I'm wondering if maybe the ladybug larvae started up higher on the tree, closer to the aphids, and I blew them off when I hosed it down last week? OMG, I might be a ladybug murderer!!
Ladybug larvae are pretty hardy; you can just push them into any handy receptacle and then push them onto a leaf near the aphids. The thing that looks like a ladybug without wings is a pupa, the intermediate stage between the larva and the adult. It doesn't move because it's undergoing metamorphosis.