This little guy, about an inch long in real life, is a Saddleback Caterpillar. They are of note for two reasons:
1. They are general feeders that will munch on a wide variety of garden plants. In large numbers, which I’ve had this year, they can defoliate a 3 year old blueberry bush in a matter of days. On doing a garden walk two weeks ago I noticed that all four of the blueberry bushes were in various states of being denuded. A cursory glance didn’t reveal anything, so I went ahead and started picking blueberries figuring I would find the predators in the early morning or late evening. That’s when it happened. I got stung.
2. The are a stinging caterpillar. I’ve been swarmed by ground hornets on several occasions, usually because I ran over a nest with a mower, and hit by bumble bees, but nothing compares to the stings I received from the Saddleback Caterpillar. I didn’t know what hit me but it hurt like crazy. I rushed inside to wash my hand and check the damage, thinking I disturbed a wasp. There were three stings in total, that I could see, all clustered in the soft part of my hand between the thumb and forefinger. The pain was like an electrical current pulsing into my hand, and yes, I’ve electrocuted myself before so know what that feels like.
A rash raised up across the back of my hand. Application of ice took out the peak pain and a follow up with a topical anesthetic made it tolerable the rest of the day. The next morning the rash and pain were gone. Though it didn’t last long, it did incapacitate that hand while it lasted.
I have been hand picking them while wearing a heavy pair of leather gloves and then disposing of them. Manual control works without much effort. Though I pulled over 40 off of the 4 bushes the first time out after discovering them, and recovered from the sting, in days since I have only picked another half dozen or so. Because of this, I don’t see a reason to spray or dust for them because the alternatives, such as BT also kills butterflies and other beneficial insects indiscriminately.
However you choose to handle them make sure and wear protective clothing and to be careful! These little guys pack a powerful punch.