Wednesday, November 28, 2018

Margined Shiny Leaf Chafer

This beautiful scarab beetle is the Margined Shiny Leaf Chafer (Callistethus marginatus). They are native to the Eastern United States and found as far south as Central America. I found this one in Fillmore, MO this past summer. It was moving around on the clover in the hay field. Even though I now know these are common, I had never seen one before.

Like most all scarabs their life begins underground as grubs where they feed on the roots of turf, plants and young trees. Some scarabs can cause excessive damage to lawns and ornamental plants if their numbers are large enough. This particular species is not known to be a pest.

They do however, resemble a beetle we have come to know as a major pest. The Japanese Beetle has been wrecking havoc from the Eastern seaboard westward for decades now. Their sheer numbers are approaching plague-like proportions. The invasive Japanese Beetle is smaller and has distinct white tufts along the margins of the elytra. 

Margined Shiny Leaf Chafer

  The Margined Leaf Chafer lacks these tufts, but has pale hairs visible along the elytra and at first glance may look like those distinctive tufts. 

Their color is somewhat similar. They both have shiny metallic bodies and wings. Each have a greenish tint to them. The Japanese Beetle has a predominantly green head, pronotum, legs and underside. The MSLC has an over all brownish or reddish-brown color with a metallic green sheen.There is usually a pale-yellowish or cream color margin along the pronotum. Legs are are light color with bands of reddish-brown.

The Japanese Beetle is diurnal whereas MSLC are nocturnal. Although you will find them resting among flowers or vegetation during the day, giving the impression that they are in fact diurnal. They frequently show up at lights at night.

This particular beetle seems to be a favorite of bats. The nocturnal habits of the beetles puts them in the path of night flying bats. Larger bats like Big Brown's are fond of beetles, and this particular species would be a manageable size for capture and consumption. The notion that bats consume large quantities of mosquitoes is a bit of a exaggeration. While they do eat mosquitoes, it just isn't at the amount we are told. If we look at it from the bats perspective....mosquitoes are tiny, lack much nutritional value and would have to consumed in extremely large quantities to benefit them. However, beetles, moths and other larger insects require nearly the same amount of energy to capture and pack a much larger nutritional punch. Compare it to humans at an all-you-can-eat-buffet. Most would not order the salad when that huge buffet beckons.