Hi, Bev! They're probably pretty close to chrysalis stage - once they're "tucked in", it takes about 1-2 weeks before the butterflies emerge. We've had them hatch as late as early October (I remember, because I brought one inside and it hatched the night of David Ortiz's last name; I named the butterfly Papi.) Looking online: the butterflies can't fly if their body temperature is below 55 degrees, so they'll sit in the sun for a long time to warm up. The caterpillars can't crawl below 41 degrees. So anyone who's out there right now will be logy in the mornings, but they should warm up quickly enough. I saw tons of monarch butterflies on Monhegan Island last September, late in the month - if they could survive those cold temps, ours should be fine! This will be the batch that migrates south, so they're perfectly synched up with the end of the milkweed and the blooming of the fall nectar plants. The caterpillars will form the chrysalis on any plants, so once they're done eating, they don't need the milkweed anymore. :-) Tammy Eustis Assistant Director, Killingworth Library Association 860-663-2000 teustis@killingworthlibrary.org -------- Original Message -------- Subject: [CT Birds] OT- monarch caterpillars question From: Beverly Propen via CTBirds <ctbirds@lists.ctbirding.org> Date: Thu, September 12, 2019 6:21 pm To: Ct Birdlist <ctbirds@lists.ctbirding.org> Most of the summer, I only had about 4-5 monarch caterpillars. This past week, There are 6 on my milkweed-eating well and very plump. But the milkweed is starting to die off. Plus the evenings are getting cooler. I didn't find any definitive information regarding what temperatures they can endure or, what happens when the milkweed supply is gone. They're pretty large and plump now, but it seems like there may not be enough time for them to make a chrysalis , and then migrate. Bev Propen _______________________________________________ This list is provided by the Connecticut Ornithological Association (COA) for the discussion of birds and birding in Connecticut. For subscription information visit http://lists.ctbirding.org/mailman/listinfo/ctbirds_lists.ctbirding.org