Reptile & Amphibian Forums

Today I found a polyphemus caterpillar crawling across my backyard deck, it started spinning its cocoon a few hours after being placed in its cage (which is outside). Now, this morning I didn't even know what a polyphemus was, but after finding the little critter and spending hours on the web doing research I have found out a lot. I am unsure on one thing though, being late July will it eclose this season or wait till spring? (I live in the central portion of Wisconsin) If it won't hatch till spring any advise on how to winter it would aslo be greatly appreciated. Thanks!

Well congrats on your find and i.d. Just a note - luna and poly's can look quite similar to the untrained eye. The most distinct difference is the brown head of the poly. That said, even if you have a luna the care is the same. Poly fly throughout the US but you are on the western range of the luna.

The most important thing right now is not to disturb it. They need to maintain the orientation they begin with or they can become trapped in the cocoon later So if you move it, keep it oriented the same way for at least a week. This gives it the needed time to finish spinning and then making its final molt into the hardened skin of the pupal state.

Being in WI, it will probably not eclose until next summer (June). However, I live in NH and have had them emerge the same season – twice after they were in the fridge – very distressing! In the off chance that it will eclose in August or Sept you can just lay it in a screen cage or plastic container with a branch/stick so that it can climb and expand its wings once it comes out – this is crucial or you will end up with a crippled moth. Keep it exposed to normal daylight hours (and dark) and outdoor temps the best you can. Keep in mind that a large moth pupa like this is a tasty meal for any small mammal so be sure it is safe. If you have it outside it must be in screen (light/rain pass through but no predators).

If by November (that is being REALLY safe) it has not come out this is what to do once the week of safety has passed.

Put a layer or two of paper towel in a small plastic container with a tight fitting lid (Tupperware type), and one drop – literally only ONE drop of water on the paper towel. Any more than a single drop and you run the risk of mold, and this will be just enough to give minimal humidity. Place the cocoon in the container (lay it as it seems to naturally fall), lid on and put in the veggie crisper drawer in your fridge. Up here in NH, I take mine out in late May, and you would do the same.

Once you take it out put it in a box with paper towel and a stick or something for it to climb on to when it emerges. I had a crippled sphinx moth in my early rearing days b/c her stick was dislodged – a very sad occurrence

Anyway, keep my email address on hand and ask questions in the spring if you need to, but for now just put it snuggly into the fridge for winter – just remember to take it out in the spring! These moths are quite interesting b/c they do not feed as adults, just mate, lay eggs and die. If your turns out to be a female, and depending how into it you are, I can give you directions on how to make a mating cage and see if you can get it to mate with a wild one – very fun stuff!

lele

Thanks lele for your help, and for not laughing TOO hard at me for my opps post above. I am almost positive I have a polyphemus and not a luna, it does not have a horizontal stripe, what it does have, or had before it cocooned, was a very large brown head and a purple "V" on it's behind. Now if this won't emerge (again, if all goes well) till spring, when should I put it into cold conditions, ie. the fridge? Should I wait till the weather outside naturally cools, or just put it in straight away after the cocoon hardens? And I am very inerested in attracting prespective mates once "she"(?) emerges, I find it absoulutly fascinating, these large awsome moths. I have always loved luna moths, with their etheral beauty, and always hoped to see one, never have. I hope my new little polyphemus charge makes it to adulthood, I have become so interested in this in 2 days! Strange sometimes how a hobby finds you and not the other way around! I am pushing 40 yrs old and this has made me feel like a kid again!