Tuesday, May 29, 2012

Click Beetle

Janet Haworth sent me this picture of an eyed click beetle, Alaus oculatus, which was in her duck pool.  It is perched on her finger so she didn't get to see its acrobatics.  When placed upside down, it has a dramatic athletic move to right itself as demonstrated in this Youtube video.

They are able to "jump" up to four times their body length high while making their loud click.  This is a very effective evasive maneuver when they are threatened by a predator.  It has a spine tucked into a groove in its back poststernum.  When it flexes its back, the spine comes under tension, then pops out like you snap your fingers, creating both the click and the jump

This video demonstrates the "click," speed and flight characteristics.
The adult's food consists of plant juices and nectar.  It has prominent eye spots which are actually colored scales like on a butterfly wing.  Presumably these false eyes are threatening to some potential predators.

Larva- Daniel D. Dye II * bugguide
Most species of click beetle larvae are called "wireworms" and are notorious for their damage to the roots of cereal crops.  Eyed click beetle larvae however are voracious predators, devouring grubs and wood boring beetles.  They come equipped with powerful crab-like jaws, built for dismembering their prey.  They spend most of their life as larvae, from two to five years total.  Bad news for grubs but good news for gardeners.

More high quality pictures by Daniel D. Dye II are at pbase.com gallery and  floridabackyardspiders.com

1 comment:

  1. Nice write-up Bob! More than I found in my quick search. He was upside-down in the pail I used to rescue him, but never got it all together to click. I think he was too surprised at the watery world in which he found himself, and perhaps happy I found him instead of one of the ducks!