IS IT A BEETLE OR A BEE?
By Amy Heilman, WORC Garden Co-Chair
Have you ever been fooled by an insect’s appearance, assuming it was one thing and then learning it was something entirely different? This happened to me one day when I heard a buzzing sound near a compost pile in my garden. As I approached the small, hovering brown ball of fuzz, I thought there was something about this strange bumble bee that looked unusual. As I peered closer, I realized it had a mottled greyish-brown shell like a beetle covering the top of the abdomen but also had yellowish-brown hairs on the legs and thorax of the body like a bumble bee.
After some research, I learned that this was the fascinating Bumble Flower Beetle! The name made me grin as it was so appropriate for this smallish, nickel-sized insect that had odd club antennae and a snout-like mouth similar to a weevil. Euphoria inda is a member of the scarab family of beetles and though it has elytra, the hardened protective set of wings that other beetles open for flight along with the softer underwings, this particular species keeps their elytra closed which creates the buzzing sound. It is thought that the buzz, along with the fuzz, aid in disguising itself as a bee, thus keeping predators away. It also emits a chemical odor like chlorine to defend itself.
These beetles are related to June beetles and Japanese beetles but are not a pest of major concern. They are native to North America. The adults lay eggs in areas with high levels of organic matter or compost piles in early spring. The larvae, also known as grubs, feed on this material along with rotting fruits and vegetables, then pupate 2–5 inches below ground.
Adults molt and emerge in late summer to feed on flower pollen and, as they do so, help to spread the pollen granules that cling to the hairs on their bodies to other flowers. Nectar, sap of plants or juice of dying fruits, also make up their food sources. Because they tend to feed on cracked or split fruit damaged by other insects, they do not spread plant diseases while feeding. They mate and lay eggs around dying vegetation and find a place to overwinter, and the process begins again in the spring. They are one of our many important pollinators, as well as decomposers, that help “tidy up” nature as they improve soil structure.
Bumble Flower Beetle photo: Joseph Berger, Bugwood.org