What's in a name?

During recent rains I was stopped dead in my tracks when I spotted this guy who seemed to simply appear on one of our back windows one morning.

I didn't know what this was, but it was clear it was not to be messed with.  The spiny protuberances had me standing on the other side of a window with my fingers curled into a fist, protectively.  Whatever the opposite of cuddly is? That is this guy.

I called for backup.  At first glance The Hub immediately reacted "asp!".  It turns out each of us had our own separate unpleasant childhood experiences with asp caterpillars growing up in Texas.

As we stood with coffee cups and shared horror stories, exaggerating the pain and suffering inflicted upon the innocent child-versions of ourselves by our initial contact with asp caterpillars, we acknowledged that 1) we were both unusually brave and fine young people, and 2) this spiny window walker was a relative perhaps, but no asp.  Asps are hairy and this guy is spiny.  Very very spiny.

I was having a terrible time trying to get a reasonable image as the reflectivity of the window coatings played games with the auto-focus on my camera. Knowing I could not leave such a stingy thing crawling on the house so close to a doorway anyway, I carefully transferred the slug from window to trowel, and carried it out into better light.

I took a few more shots and, uttering a few words of farewell, gently heaved this guy over the fence to a spot where there is no regular human or even much animal traffic.  A spot where both slug and other neighborhood travelers may stay safely separate one from the other.

Quarantine established, identification quest initiated.

It didn't take long to discover that our intimidating visitor is a Spiny Oak Slug. More scientifically, a slug caterpillar of the Limacodidae family, genus Euclea.  

According to no less stellar a source than BugGuide, there is little to no information on how to further distinguish larvae of Euclea between E. delphinii and E. nanina. Their ranges overlap and larvae vary widely.  That's all right. Spiny Oak Slug will do just fine.

Sometimes, a common name tells you most of what you really need to know.