Wednesday, 6 July 2016

Rearing Caterpillars

I have been having some good luck this year so far in rearing several of Ontario's butterfly and moth species.   I enjoy trying at least a few each year.  Rearing caterpillars can increase their chance of survival immensely.

Probably the most familiar of butterflies around here, is the monarch.  For the last few years I have reared numerous monarchs to adulthood.  If I'm lucky, I will collect them as eggs.

About three days after being laid, they hatch.  The larvae are extremely tiny and lack the bold colouring of an older caterpillar.

The larvae go through five stages or instars in which they shed their old skin for a new larger one.  In the photo below, the larvae on the right has just shed its skin.

They grow rapidly and go through a lot of milkweed.  Finally there comes a day when they stop eating and look for a spot to hang and go into the chrysalis stage.  The one below found a safe spot under the window.

In the past when I had more free time, I used to raise as many monarchs as I could find.

About a couple weeks later, the adult butterfly becomes clearly visible inside the chrysalis. This is a sign that it should be hatching within the next 24 hours.

When they hatch, I let them hang to allow their wings to pump with fluid and expand. 

Gorgeous colour.

Last year we found this unique caterpillar on a small english walnut tree.

It is the larvae of the cecropia moth, a member of Ontario's giant silkworm family, also including the polyphemus and luna moths.  They can be tougher to raise, but I decided to try it anyway.  These moths are big and very showy, but because of their nocturnal activities they are not frequently seen.  The one that I raised fed on walnut leaves all summer and created its cocoon and spent the winter that way, emerging just a couple weeks ago.

It's wings were still expanding when I took the photos.

You can tell this is a male from the large feathery antennae. 
The black swallowtail is another species quite easy to rear.  Gardeners may not appreciate the caterpillar's habit of chewing through their carrots and parsley but they are great to see around anyway.  The one below was also from last year and overwintered. 

I'll conclude with a hairstreak feeding on milkweed nectar.
Striped Hairstreak.  Thanks to those who helped me confirm my identification.


  1. That's a Striped Hairstreak! Nice find!

    1. Thanks! I'm still working to better identify those different types of hairstreaks and I appreciate someone else confirming it for me. Thanks also for introducing me to a new blog. I've added it to my list.

    2. Thanks for adding me! I thought I'd just let you know that Birding with Bird Nerd is no longer active. I do all my posts on Birds, Bugs, and Botany now! Thanks Jonathan!

  2. Excellent post, Jonathan, with a nice selection of photos to accompany it. And I agree with it being a Striped.

    1. Thanks Allen. Hopefully someday I will be able to identify them with more certainty. The recent blog posts from you and Blake have definitely helped a lot.