We were quite fortunate during our first summer of hunting for “slug” caterpillars – members of the moth family Limacodidae who get their name from their absence of prolegs, which are replaced by a sucker that enables them to move quite similarly to a true slug. We (Sarah, Steve and I) were fortunate because we were able to locate and photograph ten species of slugs. I had read about these fascinating animals before, but never realized how abundant and diverse they actually were in the Missouri Ozarks. Yes, a good amount of work and patience is necessary to find them – I don’t want to tally up the hours, but it was time well spent outdoors.
I’ve decided to begin sharing these images with a species that is probably most well known of those who have heard of the slugs – the aptly named saddleback caterpillar. As can be seen in the image below, the saddleback wears a green saddle, bordered with white. Also apparent in these images are the urticating (stinging) hairs that are concentrated along fleshy nobs located at both ends of the caterpillar. These spines are found on a number, but not all of the caterpillars in this family and are capable of delivering a painful sting that is quite similar to that of the stinging nettle plant.
The image below shows the ocellus, or eyespots, which are actually on the posterior end of the animal.
Finally, the anterior end – the animal’s head is nicely hidden under a few fleshy folds that are armed with spiny protuberances.
I look forward to sharing more examples of this fascinating group of Missouri slugs in the near future.
-OZB
A Thousand Acres of Silphiums 
34 years old, lifetime spent loving the outdoors, and not until this summer do I learn that such creatures even exist — and literally in my own backyard. Embarrassing and alarming. Thanks so much for opening my eyes to, broadening my understanding of, and deepening my appreciation for the natural world around me, sir.