A Close Look at the Black Swallowtail Caterpillar

Y'all know that one of my  passions is gardening for butterflies. But take a look at this...never before have we had so many caterpillars on one plant. 

Twenty black swallowtail caterpillars on this bronze fennel!

Look closely and you can see that they are at different instar stages.

They start out black with a white band in the first instar stage.

They shed their skin as they grow revealing the second instar stage; larger and more defined markings

In the third instar stage more green stripping is evident.

and finally looking like this as a the full grown caterpillar.

Fortunately, I have more fennel and parsley close by so there is plenty of food for all these hungry caterpillars. Black Swallowtails like anything in the carrot family (Apiaceae) which includes dill, fennel, parsley, carrot, Queen Anne's Lace (wild carrot) and celery as well as plants in the rue family (Rutaceae).

When they are ready they will wander off to find a good place to pupate.

We found this one in the pre-pupa stage on the side of a raised bed.

Hopefully a handful of these caterpillars will successfully become butterflies.