|The locust borer beetle, Megacyllene robiniae. Click to enlarge.|
You may be wondering why it is not called the goldenrod beetle...
Although we usually notice them on goldenrod in autumn, they spend most of their life cycle on locust trees. Adults lay eggs on locusts. The eggs hatch into larvae that spend winter under the tree's bark. When the weather warms, the larvae burrow deeper into the tree and pupate there. They emerge as adults in late summer and early autumn. Egg, larva, and pupa live on locusts; adults are found eating goldenrod pollen, but they hang out on locust trees, too, and eventually lay their eggs there. Calling them locusts borers makes sense after all.
There are more pictures in my previous blog about locust borer beetles. Click on this sentence to go there. I get excited about seeing them every year, so the chances are good I will be writing about them next October, too. :-)