Question
I have a catalpa tree and noticed some worms.  When I went to get them, I found several with white egg like things attached to them.  Is that really the egg?

thanks
JW

Answer
No these are not eggs but the pupae of a wasp. the Catawba worm is constantly under attack by the wasp. The wasp is actually a parasite that deposits its eggs through the skin of the Catawba. The wasp larvae actually feed on the insides of the Catawba, and when the wasps are ready to leave the host, they spin silken cocoons on the Catawba抯 skin. An infected Catawba does not survive into adulthood.

http://www.ag.auburn.edu/enpl/bulletins/catalpasphinx/photo10.htm
They are natures way of controlling the caterpillars. There is not much that can be done to control the wasps. The wasp population will vary greatly from year to year so the next generation of catalpa worms may have none.