How wonderful! By sheer luck I found two species of tent caterpillars in my yard...
A caterpillar quite common to most of us, Eastern Tent Caterpillars are quite fond of cherry trees--anyone raised in even a suburban area should be familiar with the thick white webs in cherry trees--but they will utilize many other members of the Rose family as well. (Yes, apples, pears, plums, peaches and cherries are actually in the same plant group as roses.) Large, older caterpillars have spread in my yard from the black cherry tree where I found the egg case and web to the multi-flora rose bushes (food plant in the photo below).
While puttering around my front deck, I found the beastie below on the wall of my house. This blue beauty is a Forest Tent Caterpillar. I assume it earned the name "Tent" because of its similarity to the Eastern Tent (they have been put in the same genus, Malacosoma)… Thing is though, Forest Tent Caterpillars don't build tents. But the "Forest" is apt; this species prefers oaks and maples--trees that form what we call forests.
My caterpillar book likens the white spots to "footprints" but is it just me or do they look exactly like dancing Snoopy's…? (Or penguins the other way round, as was suggested by a fellow caterpillar lover.)
Comparison shot. Forest Tents average smaller than Eastern Tents, but there might be two instars (age/development levels) represented here as well. That's about as big an Eastern Tent as I've ever seen. And still it spent the afternoon eating--yikes.
Please don't expect a follow up to the metamorphosis of these… While the caterpillars are absolutely stunning, they form drab cocoons rather than chrysalises, and the moths they turn into are about as bland as a plain brown moth can get.