How to grow a butterfly

For the last 10 years or so, we've caught butterfly caterpillars, cared for them, watched them transform to butterflies and released them. The credit really goes to my wife, who figured this out and does most of the care and feeding. We accidentally discovered this when we came home from vacation one year and the parsley plants were infested with caterpillars. My oldest son and I set out to destroy them, but my wife intervened. She captured some and a few weeks later, we discovered they were swallowtail butterfly caterpillars.

The 'configuration' is we have a butterfly bush in the back yard (clever, eh?), but we didn’t always have one. Near the butterfly bush, my wife places several planters full of growing parsley. The butterflies feed on the bush then fly over to the parsley and deposit their eggs, an event we have yet to witness. The vast majority of the ones we collect are Eastern Tiger Swallowtail.

This year’s collection started July 29th. My wife found two caterpillars in the parsley, about 3/16" (~5mm) long. If they're caught much smaller than that, they escape from the containers and get lost in the house (DAMHIK). We’re not sure how long it takes from the eggs being laid until they hatch, but I doubt it’s very long. All told, we collected eleven caterpillars this year.

On August 2nd, the first one was 5/16" (~8mm), pictured below.

On August 4th, they measured 5/8" (~16mm). They doubled their size in 2 days. Around this time, they shed their skins and transformed from black to green (note to self – next time photograph the molting). In the picture below, it's August 7th and they are now 1 1/16" (~27mm) long.

On August 10th, after growing to about 1.5" (38mm), this one entered the chrysalis stage. You can still see the caterpillar, but it is surrounded by fine, almost hair-like web.

August 11th, the webbing has transformed into a shell-like cocoon.

August 19-20, you can see that the cocoon is changing color to black. It won’t be long now!

August 21st, the first butterfly emerges. We've yet to witness the emerging process and someday, I hope to photograph it. We had two more emerge the next day and several more are getting very close.




It’s now drying its wings on a Gerber Daisy. This day was horribly humid and it took more than an hour for the wings to dry enough for it to fly away.

From a 3/16" (~5mm) caterpillar to a fully mature butterfly took about 24-25 days. On August 19th, the Philadelphia Inquirer had an article on how few butterflies there were in the Delaware Valley this year. We didn’t notice much difference in quantity from prior years however; we estimate that are as much as a month later than usual. We’ve usually completed this by late July.