|True to its name, The Giant Swallowtail is a sizable butterfly|
As it turns out there are 2 alternate food plants that these
butterflies can lay their eggs on --both of them (Prickly Ash and Hoptree) are
uncommon if not altogether absent from our particular area. Still in mid
summer, the butterflies press through our region, nectaring on an infinite
supply of meadow flowers and searching (I suspect) largely in vain, for food
plants to lay their eggs on.
|This species, like the other swallowtails, usually feed while hovering next to the flower|
Giants that fly by my house are in luck since we have a potted
Grapefruit Tree that spends the summer on our back porch. For over 25 years the
tree has never produced a flower or a single Grapefruit, but last year it
produced a crop of 6 Giant Swallowtails. Butterflies in general have an uncanny
ability to locate their foodplants, and these Swallowtails are certainly no exception.
|The egg of the Giant Swallowtail is relatively large and easy to find on the host plant|
|An early instar of the Giant Swallowtail larva (left) and an unhatched egg (right)|
|While hovering, the female Giant lays single eggs on the Grapefruit Tree leaves|
|The Giant Swallowtail larva is a convincing bird-dropping mimic|
|When it senses danger, the swallowtail caterpillar erects 2 reddish horns|
|Held to the tree branch by a silk harness, the larva sheds its skin and becomes a chrysalis|
|A freshly emerged Giant Swallowtail Butterfly hangs next to its empty chrysalis|
The Giant Swallowtail is not the only swallowtail species visiting the nature preserve these days. We’ve also seen a Spicebush Swallowtail, which for us in the northeast, is a rare treat. Our last sighting of this species took place around 10 years ago.
|The Spicebush Swallowtail is seen at the nature preserve after a decade-long absence|
As its name implies, the main foodplant for this species is Spicebush, and though that small tree is not particularly common this far north, we do have some occurring in our woods. With some luck the Spicebush Swallowtail will discover them.