A rather large, creature was found in the suburbs of Philadelphia, PA by a woman who wonders if we can identify it for her. From the excellent photograph provided by our reader, one can see that the creature in question is black with yellow stripes, and is about 2.5-inches in length, according to our reader.
The creature our reader is, in fact, a orange-tipped oakworm, or ‘orangestriped oakworm’. Found in most of the Eastern USA, this worm is the larva of the orange-tipped oakworm moth, who when fully grown is a beautiful orange color, the female sporting similar orange-tan wings, and the males having darker brown wings. These larvae feed primarily off the leaves of various species of oak trees, as made clear by their name, but will on occasion “feed on other hardwoods as well”, according to NC State Extension. The larva our reader found is quite mature, as when these critters are newly hatched, they appear green in color. Normally, they would be found up in the trees feeding and kicking down large pellets of frass (a solid mixture of wood debris and excrement), but when they are found wandering the pavements, it is a sign that they are searching for a suitable place to pupate, which is normally a couple of centimeters below the ground where they can stay over the winter before hatching the next spring. When in their pupal form, these caterpillars take on a dull, dark brown color.
Despite their pretty appearance, orange-tipped oakworms are unfortunately very damaging to oak trees when they infest them. They can gather in such large quantities that they completely defoliate a tree. With no leaves, a tree is stripped of many of its purposes: wind protection, prevention of soil erosion, and more. Yet, attempting to prevent oakworm infestations is very difficult, if not futile, given the sheer size of thing they are infesting. However, NC State Extension (linked above) does provide useful tips on how to handle residential oakworm infestations, should this be relevant to our reader. It should be noted that these larvae are not harmful to humans nor animals, but if handling these caterpillars, we would still advise caution, should there be any chance of inducing an allergic reactions from skin-to-skin contact. Thus, we recommend wearing gardening gloves if one wishes to pick up one of these caterpillars to relocate them somewhere else.
To conclude, the creature our reader found is an orange-tipped oakworm. These peaceful creatures may be dazzling to the eye, but they sure are no friend of an oak tree.