While digging a hole in which to plant a new purple coneflower in the garden, something shiny caught my eye. The size of a black gumdrop, it was a beetle. I placed it on the ground next to the hole so it would be safe from my shovel. It immediately started moving its legs like it was swimming and less than a minute later, it had “swum” itself back underground and disappeared.
A search through Insect Identification revealed my flashy, fast-tunneling beetle friend is a June Bug, also known as May beetles. I had only ever seen brown ones, but apparently they vary in color from brown to black.
During its three year life cycle, the beetle goes through complete metamorphosis from egg, to larva, to pupa, to winged adult. The egg, larva and pupa live underground, feeding on roots and decaying vegetation. It is during the larval phase that these beetles have earned themselves a place on the Wisconsin Master Gardeners website as a pest, although typically they don’t do enough damage to prompt treating.
The adults emerge from the pupa in May or June and dig there way above ground where they mate and start the cycle again. As adults, they are most active at night and feed on grass and ornamental plants.
As a beetle, June Bugs belong to the largest group of animals on earth. In fact one quarter of all animal species, or roughly 300,000 species, are beetles. Wisconsin provides a home to 140 of these species. The scientific name for beetles is Coleoptera, meaning sheathed wing. Their first pair of wings has thickened into a hard sheath, covering the delicate hind wings.
June Bugs belong to a group of beetles called scarabs. They have 16,500 relatives around the world. Two of these relatives are dung beetles, which recycle vast amounts of dung every day in the African grasslands, and the Hercules beetle, which can grow to be 6″ long and lives in central and south american rainforests. Learn more about these relatives in the videos below.
Who knew there were such exciting treasures to dig up in the garden?
video credit: David Attenborough and BBC Earth
video credit: Discovery News
Beetle Resources Insect Identification Wisconsin Master Gardeners May June Beetles Scarabs Scarab Symbolism Dung Beetles