Saddlebacks are Back!

Saddleback, picture taken by Gretchen Schmidl
Saddleback, picture taken by Gretchen Schmidl

Watch out for the invasion of the body snatchers! – no really it is just saddleback caterpillars, Sibine stimulea.  I have noticed them in my yard this year and I would rather be stung by a bee than stung by this nasty caterpillar. They look like ugly bizarre clowns or a Scotty dog in a green t-shirt!

Saddleback Caterpillar
Saddleback Caterpillar (Photo credit: cotinis)

Also known as “pack-saddles”, these caterpillars are very distinctive looking, and are the larvae stage of a brown moth native to eastern North America. They appear at the end of the summer gobbling up as much greenery as possible prior to pupating into a moth.

Non-descriptive brown moth
Non-descriptive brown moth
Saddleback Caterpillar
Saddleback Caterpillar (Photo credit: noramunro)

Saddlebacks feed on a large variety of plant material and usually are found on the underside of foliage and thus are easy to miss when  you are pruning or weeding underneath greenery. My particular caterpillars were feeding on the underside of a weeping beech and I was crawling underneath the tree to prune it.  I felt an intense burning sensation and flinched back, but they had already stung me. The caterpillars have fleshy horns on either end bearing urticating hairs(irritating bristles) that secrete venom.  These are hollow quill-like hairs that have poisonous sacs at the base of them which can excrete a poisonous punch.The venom causes a very painful swelling and can cause nausea and a rash that can last for days.

Looks cute, doesn’t it? Photo by Gretchen Schmidl

The best remedy for the stinging and swelling is the application of ice.  Also, if you use some sticky tape to remove the barbs immediately, you can reduce the amount of poison that is excreted. If you are very allergic to stings, it is best to use an epi pen for a bad reaction. I always see these caterpillars in groups of 2 or 3, so you are likely to be stung by several at once. It just gives me shivers to think about it!

Acharia stimulea Clemens, 1960 Common Name: sa...
Acharia stimulea Clemens, 1960 Common Name: saddleback caterpillar Photographer: Robert L. Anderson, USDA Forest Service, United States Descriptor: Larva(e) Description: urticating hairs Image taken in: United States (Photo credit: Wikipedia)

9 Replies to “Saddlebacks are Back!”

  1. Great report & excellent pictures. I got stung by a caterpillar eating our weeping willow tree once. It felt just like an electric shock! And it hurt for hours afterwards, so I didn’t let my kids in the back yard for a month. Wanted to make sure they had done their thing and all moved on!

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