Rearing over the winter

[Dave T]

Hi! This is my first post.

My brother and I had may great summers when we were kids, raising and releasing hundreds of monarchs from eggs and caterpillers that we found on Cape Cod. This is a pleasure that I've tried to pass on to my kids.

When up in New York State in mid October, we were surprised to find two caterpillars happily munching on milkweed. I didn't think butterflies would lay eggs that far north that late in the year, but I guess I was wrong. We brought them home and raised them until they formed chrysalises. One of them died when forming the chrysalis, but the other one did not. I left the chrysalis outside, thinking that the cold weather (we are in Boston) would keep it from forming into a butterfly, but it is now black and appears ready to pop.

What should we do? If we let it hatch, the butterfly will likely die - won't it? (Temps are in the mid 40s and below freezing overnight.) The only alternative I can see is to bring it inside and feed it and let it fly around the house until the dog gets it.

- Dave

[Mona Miller]

Why don't you just leave it outside? Thinking about the dog squishing it doesn't sound like a good plan.

[Dave T]

I think I could manage to protect it from the dog.

In any case, can you explains what's going on? I had thought that chrysalises made in the late fall wouldn't metamorphosize into butterflies until spring. Is that not true?

[Mona Miller]

Monarchs are different than other butterflies. They don't spend the winter in climates that get and stay below freezing. There seems to be a fragment of fertile females that keep laying as they travel south. Those females are taking a chance that the weather will hold and their offspring will survive. Some females are also going out of diapause (non-reproductive) during their journey if there are triggers (extended warm weather, host plants) along the way.

I just sent a box of 12 Monarchs further south in my state. The area I sent them to had weather 10 degrees warmer. You can mail or transfer butterflies within the state, but it is illegal to ship them across state lines.

Monarchs can withstand temps down to 25 degrees or lower depending on where they shelter, but extended freezing temps with wet weather will kill them. They are migrating to an area where there is shelter, temps which keep them at a resting point, and that has a bit of food and water. Mexico has temps from 30=40 at night and 50=60 degrees during the day.

Butterflies have several ways of dealing with winter. Some migrate south, others form chrysalis and spend the winter that way, still others remain as juvenile caterpillars or eggs. There are also three that spend the winter as adults in the north: Question Mark, Commas, and Mourning Cloaks.

[Dave T]

Thanks for the info, Mona! (That's my wife's name, by the way...)

So are you saying that if this butterfly hatches, I should just let it ggb and it will have a decent chance of makingn from here in Mass to somewhere where it's warm enough for it to survive the winter?

And do monarchs never hold off their metamorphosis until spring because of cold temps?

[Mona Miller]

So far, they don't winter over as chrysalis. The cycle does take longer when it is colder. If it gets below freezing that chrysalis will probably not make it. Some of us take them in and let them finish their cycle and then let them go. An adult butterfly is more tolerate of the cold and those butterflies that are born in the fall are also more tolerate. They do need temps above 50 to fly.

I don't know what "ggb" means.

I can't promise you that this butterfly will make it further south. Many do die due to cold temps. Some don't migrate all the way to Mexico. There have been small colonies found in SC, GA, and all along the coast during the winter. Some spend the winter actively mating and laying eggs in coastal areas, instead of resting. There's year round mating and egg laying in Southern CA, too.

[Dave T]

Ok, thanks. So it doesn't sound good for this little guy. It's not getting above 50 much these days.

(Sorry - "ggb" meant"go". Pesky iPad!!!)