Mothra

Last year I had one hornworm on my desert willow tree. It was apple green, about four inches long, with yellow and purple stripes and a curved horn on its end. I thought, "How cute!"

This year I saw a sphinx moth on the desert willow. I though, "How pretty! It hovers like a hummingbird, and it used to be a hornworm. Maybe she will lay some more hornworm eggs."

Then the hornworms ate all the leaves off my desert willow. 

I still thought the hornworms were cute, in a monstrous sort of way. But my poor tree!

I called the Tucson Botanical Garden and the Master Gardeners. They both assured me that the leaves would grow back and there was nothing to worry about. After all, they would pupate and turn into lovely sphinx moths, which are pollinators. I didn't have anything against pollinators, did I?

These monsters use those four pair of claws or hands or something to stuff leaves into their mouths. Out the other end, they excrete little brown poop grenades. The poop is about 1/4" long, and has incisions that look like a grenade. I can't imagine how they get the incisions on there.

So, the advice I got was to 1) do nothing and wait for the leaves to grow back, 2) spray a bacteria on the tree that would kill them, or 3) pull them off and fling them some place far from the tree. They are very selective, and won't just eat anything. 

I opted for #3. It wasn't easy. Those feet have suction cups on them, and the hornworm does not want to go anywhere or do anything but eat and turn into a sphinx moth.

I flung a few hornworms on the ground, and within minutes a roadrunner appeared, picked up a hornworm, slapped it silly, and gobbled it down in one bite. Then he repeated with the other hornworm. 

My partner in crime.