Giant Swallowtail Caterpillars and Butterflies

by Celia Collins

This is for those of you who have citrus trees. I have two, a small orange tree which I bought about 10 years ago and a 12-foot lemon tree which I started as a seed 24 years ago.

White flies have been the main pest in the trees over the years. This year something different has appeared. Last week I noticed telltale droppings around both trees indicating I had GIANT caterpillars in both of them. The first thing I thought of was the Buck Moth Caterpillar invasion a few months ago, but then I remembered all the beautiful butterflies I have seen passing through our courtyard this Spring. After scrutinizing my trees, I found out that there were “very large caterpillars who look like they are covered with tawny brown and white snakeskin.” They are beautiful. It took me about half an hour on the computer to identify them. They are the caterpillars who become the Giant Swallowtail Butterflies - huge, beautiful, black butterflies with yellow spots. I immediately sent an email to Dan Gill of the Times- Picayune to ask him if it was ok to leave the caterpillars alone. He told me if a tree is old enough with enough leaves, it should be fine. If the caterpillars don’t eat more than half the leaves, the harvest also would not be disturbed.

I check every morning and every evening.  They usually are hidden on branches or under the leaves during the day, they eat at night.  One by one the larger caterpillars are disappearing.  I’ve never seen it happen, but I am hoping they are becoming butterflies and flying away (away from our cats!).  There are two small ones left on the orange tree (the lemon tree is too high to really see what’s going on).  So, to all of you with citrus trees who might find these tawny/white caterpillars making themselves at home in the branches and on the leaves, think twice before you disturb them.  They are actually beautiful butterflies in the making.