We had our first encounter with this menacing little caterpillar while we were picking Elderberries.  Lauren was reaching for a bunch of berries when all of a sudden she quickly pulled back her hand saying she had been stung.  I looked at her pinky finger and it was all red and welts were starting to show where she had been “hit”.

It didn’t take us long to find the culprits….

I cut the twig where we found these little caterpillars and put them in a bag to take home to photograph.

They’re very cute and quite beautiful but oh, do they hurt.

These are called Saddleback Caterpillars.  I had never seen them before and after watching Lauren and the pain she was feeling, was glad I had never encountered them before today.  After reading about them, I was quite intrigued about their natural defense mechanism.  Lauren was still dealing with the affect of the stings 2 days later – and these weren’t even adults!

Here’s what the experts say:

Saddleback Caterpillar

SIZE: 1 inch (25 mm)

COLOR: Purplish-brown body with a purplish saddle shape on its green back.

DESCRIPTION: The saddleback caterpillar is about an inch long, and has poisonous spines on four large projections (tubercles) and many smaller ones that stick out from the sides of its body. The “saddle” consists of an oval purplish-brown spot in the middle of a green patch on the back. Saddleback caterpillars feed on the leaves of basswood, chestnut, cherry, plum, oak, and other trees and shrubs.

HABITAT: The saddleback caterpillar is a general feeder and is generally found on shade trees and ornamental shrubs in late summer.

LIFE CYCLE: Adults tend to take flight in mid-summer.

TYPE OF DAMAGE: The poisonous hairs or spins are hollow and connected to underlying poison glands. Contact with them causes a burning sensation and inflammation that can be as painful as a bee sting. The irritation can last for a day or two and may be accompanied by nausea during the first few hours. Usually the site of contact reddens and swells much like a bee sting.

CONTROL: A person “stung” by a poisonous caterpillar should immediately wash the affected area to remove any insect hairs and poison that remain. An ice pack will help reduce swelling, and creams and lotions containing steroids will lessen the discomfort and promote healing. Persons known to be sensitive to insect stings should consult a physician. Stinging caterpillars rarely occur in sufficient numbers to be considered plant pests, but people who work with ornamental plants should learn to recognize them and avoid touching them.

Eric Day, Manager, Insect Identification Laboratory

For as beautifully striking as these caterpillars are, it would be a good idea to admire them from afar!