Posted by Dan Treuz on October 29, 2006

Q: Dear Sir or Madam,

I found a wooly bear caterpillar and have been feeding it for the past 2 weeks and it ate with great appetite.

As now the days are getting colder, it has become more inactive, crawling only little and hardly eating. Also I noticed that the abdominal and anal prolegs are not sticking so well anymore.

I wonder whether the caterpillar is entering a dormant phase (as it hibernates during winter) or is shortly before a molt as mobility of the abdominal and anal prolegs is reduced (as the skin might harden during the molt?)?

Thank you

PS: I am right now in Mexico (Near Guanajuato)where nights are about 10?C

A: It does sound to me that your Woolly Bear is getting ready to find a location for hibernation - become dormant. Sounds like you've done your "homework" and know quite a bit about your animal. If you plan to keep your bear, make sure it's in temperatures that will allow it to stay dormant until the return of spring. Your little guy will remain as a caterpillar all winter and only change into the pupal stage in the spring. Sorry, but I can't give you any information on its mobility - you know more than I do on that from your observations. The kind of observations you're doing will make you the "expert" on Woolly Bears. Thanks for sharing and good luck with your little guy.

John Wiessinger ( October 30, 2006)