One of the reasons I love to host garden tours here is because when lots of gardeners get together, I never know what great information I'm going to pick up myself. The collective knowledge, experiences and diverse perspectives of a group of gardeners always seems to result in an exciting and dynamic interchange of information and useful advice. Not to mention, sometimes I learn a thing or two about my own gardens. This weekend I hosted a tour of our habitat landscaping, sponsored by New England Wild Flower Society. As we passed one of the Serviceberry/Shadblow (Amelanchier) trees on the property, somebody pointed out  a large caterpillar on one of the  leaves. When I finally spotted what she was pointing at, I saw this little guy, very well camouflaged on the leaf:


We all marvelled at her sharp eyesight for picking this caterpillar out of the background! His green and yellow coloring almost perfectly matched his surroundings. That's a survival tactic on the part of the caterpillar to make itself invisible to birds looking for a nice juicy caterpillar snack.

But what kind of caterpillar was it? What butterfly or moth does it morph into at a later stage of its life? Not to worry, Bonnie Drexler (Education Director at NEWFS and a teacher/naturalist herself) happened to be on the tour. She took one look and said "Tiger Swallowtail". That makes sense - we have lots of those butterflies here in summer (see photo below). Bonnie also went on to explain that what appear to be large eyes on the top of the caterpillar are not actually eyes but another protective device, to try to look like a snake to scare off predators. Their eyes are actually at the opposite end of the caterpillar. This survival tactic must be fairly successful, because I see Tiger Swallowtail butterflies in just about every garden that I visit for my work.


I later checked one of my caterpillar books, and sure enough, Amelanchier is listed as an alternative host plant for Tiger Swallowtail caterpillars. They more frequently prefer plants in the Cherry or Magnolia family, however. Cherries and Magnolias are very common in home gardens of the northeast, which is why the Tiger Swallowtail is one of New England's most familiar butterflies.