A new and interesting (some might say, "weird") exotic insect was introduced by accident into the USA from Europe in the 1940s and is now known to occur in parts of New York, Pennsylvania, the Pacific coastal states, Colorado, Michigan, Nevada, Utah, Idaho and as of this summer, Indiana. Snailcase bagworm (Apterona helix) caterpillars feed on the foliage from a wide variety of ornamental plants, crops and Christmas trees. The pest becomes most obvious when the caterpillars move in late summer to house siding, automobiles, trees, fence posts and other solid surfaces and form pupal cases that look like "small coils of fecal matter or clumps of dirt." Pupal cases are only 1/4-inch in diameter; close inspection is necessary to distinguish them from small clods of dirt.
Please let us know if you see anything like this in Iowa (and you can be the first to report a new state record!).
For more information see the Penn State Fact Sheet .
This article originally appeared in the 1/16/2004 issue.