CATERPILLAR OF THE WEEK: The Ashen Pinion, Lithophane antennata, is one of many species of unassuming, green, cylindrical caterpillars we find in abundance each spring. But don't be fooled by its mundane dress, this caterpillar is a BEAST in disguise!
The Ashen Pinion will chow down on a fresh spring oak leaf, but given the choice between greens and a juicy inchworm caterpillar, the pinion has a clear taste for flesh. Many have read about the exotic predatory caterpillars of Hawaii, but who knew of the carnivore in our own backyards?
Below is a story of how the Ashen Pinion takes advantage of the bounty of introduced winter moth caterpillars that have been plaguing the New England coast over the last decade. The abundance of these easily caught inchworms has created a unique parking-lot food chain that is fascinating to observe.
There are too many caterpillars for the trees:
They cover every surface underneath the large pin oaks that once shaded this parking lot. Now the oaks stand tattered and naked, and the evening light filters through unobstructed. Invasive wintermoth inchworm caterpillars are the most numerous. They cover the tree trunks, coat the parking lot barriers, and hang down from the devastated treetops by silken lines. Parked cars are quickly covered with their bodies, dry and crackling in the sunlight, and any visitors must run for cover to protect their scalps from filling up with tiny frass pellets.
Mixed in with the wintermoths are an assortment of other leaf-eating caterpillars: Twig-like Phigalia inchworms and robust green Amphipyra pyramidoides. This is a world flooded with meat. Overabundant, writhing, everywhere: meat. It is also a chance to watch the opportunists; animals, predators, sometimes predators, have gathered here to take advantage of this spectacle.
Along the wooden barriers of the lot, inchworms move in a stream as if this were a highway. But it is a treacherous journey. Here and there, wolf and jumping spiders join the flow of caterpillars, darting across the boards to grab a meal. A train of ants course up one of the posts and down another, conveying away many bodies. A stinkbug drinks from the limp body of a now unrecognizable larva. Predatory insects are numerous and diverse here.
But perhaps the most unexpected member of this impromptu food chain are the Ashen Pinion caterpillars. There are about twenty of them mixed in with the riots of inchworms, and from afar, it is difficult to differentiate them from the masses. That is until, with great speed and accuracy they snatch up a passing inchworm and devour it with piercing mandibles in seconds. Pinions eat leaves too of course, they probably began life feeding on the pin oaks above. Watching them feast on the inchworms now though, it is hard to imagine they will ever return to their innocent leafy diet.
-Sam Jaffe, TCL Executive Director
"Caterpillar of the Week" will highlight a different species we grow in The Caterpillar Lab each week… or, you know, at least SOME weeks. We hope you enjoy meeting the caterpillars of New England!
More information on the Ashen Pinion on BugGuide here:http://bugguide.net/node/view/29931