Sherry, the Polyphemus spins a white cocoon. Unlike the Luna, the Poly cocoon is quite dense. They spin a LOT of silk! Their cocoons look like tiny surgical casts. In fact, it is because of this, that the Poly's first cousin, native to China, Antheraea pernyi, was and may still be used for silk, just as the Bombyx is. The Cynthia moth is also used for silk. At one time, Cynthias were common in NE US, but have largely died off, chiefly due to habitat loss as well as parasitoids such as the tachinid fly. Susanlynne, one sureshot way to tell male from female Luna, at a glance, is color. The females are that characteristic green, while males are yellow-green. I could tell from my upstairs bedroom window, the Luna I saw, resting on a young hickory, was most definitely a male. No way could I see its body size or antennae. I hope this helps.

I got this in the beginning of May. What I thought was spider strings was actually the larvae of the gypsy moth. My rash and itch were so bad I was put on Prednisone and Benadryl to counter act it. It's been 27 days and it is just now starting to go away. At first I thought it might be poison ivy or one of the others but the rash did not leak like it usually did when I got it. After 3 days of sleeplessness I finally went to the doctors and was put on medication.

Looks familiar to me, although the background of your photo is much nicer than mine. Azalea moth caterpillar.

I have five imperial caterpillars raised from eggs found on my concrete porch. Three have reached the fifth instar together; one is already pupating. The Other two were smaller since the third molt and one died during the final molt. Now the other small one is going the same way. The molt started normally but then the cat began looking weaker and a brownish fluid appeared. The skin did not shed normally and the cat wasted away. Now this one is wasting. Does anyone know what this is?