Question
We have a Sunburst Honeylocust Tree located in our back yard.  We purchased this house about 6 years ago, and I would estimate that the tree was about 3-4 years old then.  We noticed that the past two summers the tree has these webbed together leaflets that turn brown around July and then we have these 1/2 to 1 inch long green worms that spin down from it on what appears to be silk web.  We are not for certain why it just started 2 years ago, but it has made it impossible to enjoy our back yard because of the web strings that hang down and the worms that fall on you.  I have researched the problem and belive they are mimosa webworms although we have never seen one of the adult moths.  The damage it does to the tree in the summer is terrible and by late summer the tree is completely brown and defoliated.   
What type of treatment can be done to prevent this.  The tree is still pretty management as far as spraying it, but what I can't find is when it is best to spray the tree.  It seems that two generations of this worm are present on the two during the year, so when do I begin to treat and how offend should I do this?

Answer
spray with formulations of acephate, azadirachtin, Bacillus thuringiensis, bifenthrin (Bifenthrin Pro Multi-Insecticide, Onyx Insecticide, Talstar F, Talstar Lawn & Tree Flowable, Talstar GC Flowable, Talstar Nursery Flowable, and TalstarOne Multi-Insecticide only), carbaryl, chlorpyrifos (Dursban 50W only), cryolite, cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, diflubenzuron, disulfoton, lambda-cyhalothrin, permethrin (Astro Insecticide and Permethrin Pro only), pyrethrins and piperonyl butoxide, spinosad, tau-fluvalinate, and trichlorfon are labeled for webworm management.
Management Hints: First generation adults appear in June and lay eggs on flowers and foliage. Manage first-generation larvae as they hatch from eggs in mid- to late June. Second-generation larvae may require treatment in August.