I saw a weird beetle bumbling across the carpet in my bedroom the other day. As entomologists do, I scooped in a jar, popped it in the freezer, and forgot about it until my spouse reminded me that beetles are not food (In much of the world, beetles are food, but it didn’t feel like the moment to bring that up.) So I brought the beetle to school, pinned it, and left it on the lab bench. I totally forgot about the beetle until a friend of mine sent me a photo of the exact same beetle, wondering what it is.
Meet the Buttercup Oil Beetle (Meloe americanus). It lives throughout the southeastern US, is almost completely unstudied, and has evolved a remarkable way to make a living. Mama oil beetles dig holes at the bases of plants where they lay their eggs and apply some goo to make them stick together. When the baby beetles hatch, they bolt to the top of the plant and, hopefully, onto a flower. But these are not normal baby beetles, which are wormy and soft. These baby beetles are built to hop rides on bees.
When a bee lands on their flower, one or more of the baby beetles hop on. If it’s a male bee, the baby beetles wait for him to mate and, when he does, they hop onto the female. The female bee eventually digs a hole where she lays her eggs and deposits pollen and, unwittingly, baby beetles, who land in a warm ground nest with a buffet of pollen and baby bees on which to munch.
Once the Buttercup Oil Beetle larvae make it into the ground they are all set, but an estimated 99% die on the journey from flower to bee nest. The journey of these young beetles is enough to impress Odysseus, under whose feet they, or at least their close relatives, undoubtedly lived.
Emily Meineke is a PhD student in Entomology at NC State. She’s interested in how human pressures (like urbanization) change the insects that live around us, particularly herbivores that endanger trees. Follow her on Twitter: @EmilyMeineke.