The late-season handiwork of the Basswood Leafroller (Pantographa limata, family Crambidae (Crambid Snout Moths)) clearly describes the unusual leaf-abodes created by this moth caterpillar. Individual translucent green caterpillars reside inside cigar-like nests created in a repeating three step process.
The caterpillars first use their sharp mandibles to cut a small slice of the leaf, starting near the leaf base. Once a cut spans about 1/2", the caterpillars roll the liberated part of the leaf and secures the furl with silk "stitching." This cut, roll, stitch process is repeated in the direction of the midrib to create a rolled cigar-like nest. Each nest contains a single larva and each leaf appears to be able to support no more than two nests.
The caterpillars then reside inside their rolled homes where they feed as leaf skeletonizers. It appears this late-season caterpillar has one generation per year with the caterpillars overwintering as pupae. However, I could not find a solid reference indicating exactly where the caterpillars pupate. Some say the caterpillars abandon their leaf rolls to pupate in the ground just prior to fall leaf-drop. Others say the caterpillars pupate inside their leaf-abodes and spend the winter inside fallen leaves.
Three hosts for this moth are listed in the Peterson Field Guide to Moths of Northeastern North America (2012): basswood (Tilia americana), oaks (Quercus spp.), and rock elm (Ulmus thomasii). However, other references indicate caterpillars are only found on members of the Tilia genus while some confine the host range to American basswood.
I could find no references that describe the basswood leafroller as a significant pest on either its namesake host or the other reported hosts. The leafrolling activity that we observed a little over a week ago during the First Annual Tree and Plant Diagnostic Walkabout Workshop held in Lake Hope State Park in Vinton County, OH, was confined to a single large tree. While the leaf rolls were very evident, we doubted that the late-season damage was causing significant harm to the overall health of the affected tree.
