I had a Cox's Orange killed by them, relying on the advice out there that "they are no big deal." It took a couple of years, but they damaged all the tree's bark so much it just finally croaked. Blasting water works a little, but there is white fuzz back within a week, AND you have to hold the branch to effectively blast them off, so once a tree gets so big, that's pretty much a useless task. I now have them again on the one tree I didn't buy on M111, so I assume it will eventually die too, because they are impossible to effectively control. All my M111 trees are barely affected, so that is the only solution, IMO. Carla in Sac

Ian - THANK YOU! That looks like exactly what I have. I am going out for insecticidal soap this morning. I have a tree sprayer which ought to reach, and it sounds like the soap won't harm the other residents of the butterfly garden. Curious how rapidly these appeared and covered the tree! I am thankful not to have a forest of those trees ... :)

If you can move the white stuff, or squish it, then you are probably dealing with mealybugs. However, if the white fuzz seems more permanent and doesn't squish I'd say you are looking at the eggs of the sharpshooter leafhopper. I haven't seen mealybugs on citrus much, but the leafhoppers typically do their egglaying on the midvein or petiole of leaves of a variety of plants. This actually doesn't harm the plant much as long as they are healthy. Don't confuse this leafhopper with the glassy-winged sharpshooter, an imported species that is causing problems in the grape industry and others.

Thank you, JOhnmerr and Rhizo 1 for your replies. I have never had this problem before. The grapefruit tree is 8 years old and the lemon tree is 2 years old. Can these "wooly aphids" kill our trees? I will look up how to treat unless you have suggestions. The grapefruit tree is way too big for me to sponge off with water and soap. It's about 15 ft. tall Ants have been very bad herein Texas this year due to the drought last year and the past warm winter then lots of rain in the early part of the year. Geeez...ants have been everywhere. I have been treating them with orange oil and molasses. Should I prune back some of the branch's to allow more airflow or is that not an issue? Thank you again ;)