Saturday, September 4, 2010


I found this chrysalis attached to the wall outside my garage door. I’ve been checking it every time I’ve gone in or out and when I took these pictures, I thought it was nearing time for the adult butterfly to emerge. A close look reveals patterns and colors of the soon to exit butterfly.

The shape and the silk thread acting as a safety harness tell me this is a swallowtail and the vertical orientation is the standard position of a Black Swallowtail. The process of pupation in this species is really an interesting process and a bit dangerous for the butterfly. In this case, the larva created a silk pad on the wall and then moved up so its hind prolegs were on the pad. Once secured to the pad, it produced a strand of silk that circled its body and attached to the wall. After a period of rest, it began to shed its skin. The wriggling motion that moved the skin down the body also caused projections on the side of the chrysalis to catch on the silk strand. The final act was the tail end casting aside the shed skin and anchoring itself to the silk pad. Failure to properly attach to the silk harness could cause the chrysalis to miss attaching to the silken pad and cause problems in development and emergence.

I was away for about two hours and when I returned, the butterfly was gone. Nothing left by a shell.

I didn’t have to look far for the newly emerged adult. I found it at the base of the wall, sitting on a plant tray that someone hasn’t yet put away. There’s nothing more perfect looking than a freshly emerged butterfly. This is a female Black Swallowtail.

She didn’t stay around for very long. After a few minutes she took wing and headed out across the field. She doesn’t have any time to waste. Black Swallowtails overwinter in the chrysalis form, so she has to mate and lay eggs and the larvae have to grow to form a chrysalis before cold weather sets in. I hope her kids pick a more secure place to spend the winter than on the side of a house.


  1. Just fascinating, Steve! It pays to be observant. How long was the chrysalis there do you think? ~karen

  2. Hi Steve ....I'm still here..Earl was a no show thank goodness!!
    That is a beauty ..the Black Swallowtail!!
    A perfect picture too!!
    She will have to hushel to get her mission accomplished!!
    Maybe you could hang a heating pad on the side of your garage!! ; }

  3. Wow! In Ohio this spring I kept seeing black swallowtails (small b, as in swallowtails that were black, not Black Swallowtails) but was too much of a butterfly ID novice to ever figure out what species I was looking at.

    Grammie G, we were watching Earl nervously down here in Georgia for a while too!

  4. When I was a kid I used to collect butterflies, it's a wonder Grammie G doesn't have nightmares about it. Anyway, I knew exactly what your chrysalis was even though I haven't seen a black swallowtail in years. When I was young mom always grew dill and parsley and I would find the caterpillars all the time. I'd put them in a jar and raise them until they would form their chrysalis and hatch. Perhaps I need to start growing some herbs to relive my childhood. :) Thanks for a blast from the past.

  5. Karen – I first saw it about 12 days ago. It was almost totally green then.

    grammie g – That cold front flew through here so it could knock Earl away from the coast. It got quite cold last night, so the butterflies were slow to get moving this morning.

    Rebecca – It takes a while to get those swallowtails sorted out. I have to refresh my memory each spring.

    Renee – I think every kid should have a chance to raise a few butterflies. It’s amazing how many kids don’t know how the transformation takes place.