yellow and turquoise bug
Saw this bug while taking a walk. About an inch long for body.
Never saw such beautiful bright colors.
Looks like it’s been painted with metallic auto paint.
Kennett Square PA
Hi Cathy and Carlos,
This beauty is an Elderberry Borer, Desmocerus palliatus, also known as a Cloaked Knotty-Horn. The larvae burrow into the stems and roots of elderberry shrubs and the adults feed on pollen.
2 thoughts on “Elderberry Borer Beetle”
I saw these large, lovely beetles for the first time last June in a remote, sparsely populated area in western, Winchester, CT, though I work as a field ecologist all over Connecticut, and see elderberry all the time. Are the adults out only for a brief window perhaps? Or Is Desmocerus palliatus declining? If so, why? Has anyone looked into this? Attracted to outdoor lighting, maybe? Pollution-related issues detecting the pheronomes emitted by females in the stems? Elderberry populations too fragmented? Are the leaves distorted due to the interior stem damage? Are you sure the adults do not nibble somewhat on the foliage? Something else: I have noticed that winter kill is very common in common elderberry in CT. Is this perhaps the result of stem borer damage? I do have sharp photos showing distorted, slightly bitten leaves if anyone is interested.
According to BugGuide, the Elderberry Borer is “uncommon” and “Adults feed on pollen, found on flowers, especially those of elderberry.” There is no mention of the adult Elderberry Beetle eating leaves.