The e-mail was short and anonymous. The writer had found a strange creature on a lawn chair. The subject line read, "help with creature." That's really what caught my eye. The only description was that the creature was, "the size of a silver dollar and covered with little hairs." Fortunately the e-mailer had also attached a digital photo.
When I saw the photo, I immediately experienced a flash of recognition. It wasn't something I've seen often, but it was vaguely familiar. At first glance, it looked like a small peach-colored fuzzy octopus. Several sets of long and short arms protruded from the side of the body.
For a moment, I was stumped. Then I decided it might be some sort of odd caterpillar. So I grabbed "Caterpillars of Eastern North America" by David Wagner (2005, Princeton University Press). Amazingly, the mystery critter was one of the first species illustrated. It was a "monkey slug," caterpillar of the hag moth (Family Limacodidae).
Wagner describes slug caterpillars in general as "more fantasy than reality." And he says the monkey slug, "may be North America's strangest caterpillar. It looks more like the cast skin of a tarantula than it does a caterpillar." Most species of slug caterpillars occur in the tropics, so this comparison has some biological merit.
While some slugs are ordinary and dull, others are lobed, spiny, and/or quite colorful. From above, it's difficult to tell these masses of protoplasm are even caterpillars. Their legs are hidden by their broad body and when examined from below, they have suckers instead of prolegs on their abdominal segments. Consequently they glide, rather than crawl, when in motion.
Another odd one
The spun glass slug is another oddball. Its internal organs are visible as a long dark stripe running the length of the body. Knobs arising from each body segment are armed with stinging spines. Another half-dozen species bear stinging spines and intriguing colors, but the most formidable is the saddleback caterpillar. The lime green saddle on a brown body and clumps of fearsome-looking spines make this species easy to recognize, but don't pick it up. Wagner compares its sting to stinging nettle in both intensity and duration.
So, beware of spiny caterpillars. Those spines can pack a wallop. On the other hand, don't be fooled by cute, furry caterpillars. Larvae of some flannel moths (Family Megalopygidae) appear harmless, but their soft outer hairy coat conceals many stinging spines. The caterpillars of the two hairiest species remind me of a tiny Cousin Itt from the Addams Family.
Another e-mailer this week asked an interesting question about spiders. Joe Hoesch of Pittsburgh came upon a huge spider in a country store. "This thing had long legs, a large head and a huge round body," Hoesch wrote. "I coaxed it into a coffee cup and headed outside to release it. In the sunlight, I noticed that the big round body turned out to be dozens of young spiders hanging on for dear life. Is that the biggest spider in this part of the state and is carrying young piggyback normal?"
Wolf spiders (Family Lycosidae) are among the largest spiders in the east, and capable of sending even macho football players into hysterics. They are active predators, and females typically live for several years. Though they can bite, they are harmless compared to black widows and brown recluses.
Female wolf spiders lay dozens of eggs at a time, which they wrap in a ball of silk and carry until they hatch. At that time the spiderlings escape the egg sac and climb up the females legs and gather on her back, where they live for several weeks until they are big enough to hunt on their own.
I remember the first time I encountered a "pregnant" wolf spider. A friend was trying to kill the spider and when attacked with a stick, scores of tiny spiders scurried off in all directions. It's an image I'll never forget, and I can only imagine how someone afraid of spiders would react at the sight of one huge spider exploding into a cascade of tiny spiderlings.
Send questions and comments to Dr. Scott Shalaway, RD 5, Cameron, W.Va. 26033 or via e-mail to firstname.lastname@example.org.