Question
I believe I have found a Catalpa worm in my garden feeding on a Guara plant.  It is about 2 inches long and has a horn on the end.  Do they live in Nevada?  Are they dangerous to my plants and trees?  What should I look for to determine if there is larvae in my trees?  

Answer
Catalpa "worm" only eat Catalpa tree leaves so they will not harm your garden or any other tree. IF there are Catalpa trees in Nevada then there is catalpa worms. There are several caterpliiars that have "horns" on the end --generally a caterpillar will eat certain plants and is usually named after that plant Exp: Tomatoe Hornworm. Either pick the caterpillars off the plants or spray the leaves with an insecticide such as BT. Check with your local garden type store for an insecticide.