Wednesday, July 29, 2009

How to Raise Eastern Black Swallowtail Caterpillars

Every spring we plant a lot of parsley, dill and fennel in hopes of luring the Eastern Black Swallowtail (Papilio polyxenes) to lay her eggs in our garden. Last year we released over 25 EBS butterflies, which we raised from larva to adult. This year we haven’t found nearly as many, but we do have some. Just today I found this beauty on a a Queen Anne’s Lace (another host plant of the EBS and another reason to let a patch of QAL grow wild in your yard).


Eastern Black Swallowtail caterpillars look different at different stages; those stages are called instars, and the caterpillars shed their skin between each. I was so surprised when I first learned this and then saw it with my own eyes.


We like to give our caterpillars lots of room to move and lots of the fresh food to eat. Our EBS habitat is an aquarium with parsley planted directly in garden soil. Parsley grows really well this way, fennel and dill usually get too big so if an EBS prefers fennel, dill or Queen Anne’s Lace then I have to replace it daily. I just place the fennel and dill in the tank mingled in with the parsley in hopes that the caterpillar will go for the parsley (usually they do if they are young enough when placed in the tank). I am not a fan of the plant in a vase of water method because I have seen caterpillars fall into the water and drown. My sister Katrina (a butterfly expert at a local arboretum), recommends putting the stems of freshly picked larval host plants in green oasis that has been soaked with water, this keeps the plants fresh longer and doesn’t endanger the caterpillars. We put sticks in the habitat for the caterpillars to form their chrysalises on when they are ready. We have a screen top made to fit on this aquarium to keep the caterpillars in and the predators out. Sometimes the caterpillars like to make their chrysalises on the top, which is fine, but we have to be careful when we move the lid to put fresh food in, water or release butterflies.

The Eastern Black Swallowtail will overwinter in a chrysalis if it hatches from an egg in the fall. If it is kept in a safe place outdoors for the winter, a beautiful welcome of spring is in store come May. With good care and a little patience the beautiful caterpillars will become beautiful butterflies!



*Jump over to 5 Orange Potatoes at Wodpress for a better look of the photos.

13 comments:

Tara said...

What an amazing project and transformation to observe!

I find the caterpillars just as beautiful as the butterflies.

Sherry Gann said...

We have been searching high and low for caterpillars--any kind of caterpillars, to no avail. :(

I really like your aquarium set-up--G would love that.

Anonymous said...

Really interesting and wonderful. I love how thoughtful you are in caring for these beauties!

Shady Lady said...

So cool! We are learning about butterflies right now.

Stephanie said...

Lovely!
We've looked too, but have only really found little green inch worms. :) Which we still love.

gardenmama said...

Such an interesting post. We have been so fascinated by the many types of butterflies and large moths we have seen this summer. The 'eyes' on the wings are amazing! We leave our fields un-mowed for this very reason.

Lily said...

You think I was being funny in my http://annie.paxye.com/?p=1461 post, but you've just proven that I wasn't exaggerating. I learn so much from you and you inspire me everyday!

Kelly said...

Just beautiful!

silverpebble said...

Wow this is very exciting indeed. Those butterflies are stunning x

tree said...

Very cool! We just raised and released a swallowtail, and now we are raising monarchs. We love raising and releasing butterflies too. :) It is always so magical!

Amy Perrotti said...

Love all your nature photos. Beautiful butterfly! :)

Grandma said...

Thanks so much for identifying the catepillers that I found on my parsley. Noone thinks to post pictures of the instars. I remember seeing and being amazed by the mother this summer. I will try to help these babies make it to spring. I appreciate your help.

Grandma said...

I have overwintered 6 crysalis and so far have lost 2 when the butterflies emerged a week ago. A 3rd has emerged and appears to be weak. It is still in the 40s here at night. Why have they emerged so early? Is it temprature or daylight that triggers the emerging? Any advice?