Monday, February 15, 2010

Eyed Click Beetle (Alaus oculatus)

OTHER COMMON NAMES:  Eyed Elater, Eastern Eyed Click Beetle.

SIZE:  Around 1 1/2 inches (40mm).

FOOD:  BugGuide says adult beetles may take some nectar and plant juices.  Larvae are predatory.

The larvae of most click beetles are called wireworms.  Several feed on plant roots and can be serious agricultural pests.  However, the Eyed Elater larva is a meat-eater that feeds on many other noxious larvae, including those of wood-boring beetles, flies, and other undesirables. The large larva (up to two inches) has two powerful jaws to aid in disabling and dismembering prey.

LIFE CYCLE:  Eggs are laid in soil.  Larvae are usually found in decaying wood, under logs and other dark, damp places.  The Eyed Elater spends most of its life in the larval form, perhaps as long as 2-5 years.

RANGE:  Widespread in eastern and central North America.  Usually found in deciduous and mixed forest and woodlands.  Adults are attracted to light.

CLICK BEETLE MECHANICS (from the University of Maryland):  "Click beetles have a remarkable spine on the undersurface of the first segment of the thorax. This spine fits into a notch on the second thoracic body segment just between the legs. The spine and notch are part of the engineering that give this beetle its click. The beetle flexes its body in such a way that the spine quickly releases or snaps with a click. When placed on its back, this snap can catapult the beetle in the air. The beetle often lands right side up. If the beetle lands on its back again, the process is quickly repeated until the beetle gets it right."  (Please see the University of Maryland site for photos of the click beetle's spine and notch.)

THE "EYES":  The large "eyes" on the beetle's pronotum are, of course, only eyespots.  They and the other spots on the beetles mottled body are made up of tiny, light-colored scales similar to scales that make up the patterns on a butterfly's wings.  The eyespots are presumed to distract and confuse would be predators.  The Eyed Elator's true eyes are on its head near the base of the antennae. 

Other Sources and Links:
University of Florida 
Texas A and M University

This post is one of many submitted for the debut issue of a new blog carnival dedicated to "the celebration of beetles—of their indescribable beauty, amazing forms, and astonishing diversity."  The name is taken from a quote by British geneticist and noted evolutionary biologist J.B.S. Haldane. When asked by an English cleric what his studies of nature’s diversity had taught him about the Creator, Haldane reportedly quipped, "He has an inordinate fondness for beetles." An Inordinate Fondness was originated by and is hosted this month by Ted MacRae of Beetles in the Bush.  Thank you, Ted!




Birdy Official said...

Interesting pictures and information. The false eyes make the beetle very unusual. Never saw it before, probably doesn't exist in our area.

Lisa at Greenbow said...

I have never seen this beetle before. I know there is a world of beetle lovers out there. This beetle site will be interesting to look at.

Anonymous said...

Thanks for posting about click beetles! This February I am already enjoying the impatient spring sounds of birds and the crowns of bulbs blooming. Now I'm itching to get out my lights and sheet and go mothing as soon as the insects get active enough. I see almost as many beetles as I do lepidoptera. :)

Shelly Cox said...

Great post Marvin. I love the Eyed Click Beetles, they are so crazy looking. One interesting little fact about them I will share...."they bite, HARD!" hehehe

Lana Gramlich said...

Good luck with the celebration of beetles. This post was quite informative. I got some nice close-ups of click beetles a year or so ago, myself. I'd never seen one in "real" life before. They're pretty impressive!

Anonymous said...

I saw one of these bad boys when I was living in the mountains outside of Boulder, Colorado.

Anonymous said...

I had a very close encounter with one of these just yesterday. Had to find out what it was, for I had never seen one before in my life! I live in southeast Michigan. It seemed to be curious about the stain I was putting on my deck. Possibly because it was looking to bear its young into it before I stained? Big props to the site for an answer.

Marvin said...

I don't know why the beetle would be interested in your deck. Maybe it was just happenstance. They lay eggs in the soil and the larvae make they way into rotting wood in search of prey. Even without the stain, your deck wouldn't qualify as rotten for a few years.

Tabishai said...

Wow, we just found one in our friend's yard in south central Ontario, Canada. I am going to bring it in to our daycare so that the children can see it too!

orangecicada said...

They do bite? I read they don't.😞

Marvin said...

The do not bite.

Unknown said...

I found one of these in my fish tank??? Here in Aurora Colorado. I guess he must've gone in there because of the light. I rescued the big guy from a watery fate and put him outside. I was surprised to learn that they're rare in Colorado, and are usually from forests?? I live in the plains/city.