One of the largest insects in Iowa is a scarab beetle (Junebug) called the hermit flower beetle (Osmoderma eremicola).  The adult beetles appear in July and August and are about one inch long and dark brown to mahogany brown in color.  The hermit flower beetle is similar in general appearance to the typical Junebug except that it is not quite as oval and it is flat on the top.  The beetles are strongly attracted to lights at night and are frequently discovered in a wide variety of situations.  The adults are harmless and no control is needed.

The beetles develop from larvae that are extra large, c-shaped white grubs found in very rotted wood such as old stumps and logs on the ground.  Larvae may be up to 1.25 inches in length.  The larvae are not pests of trees; they are present only after the tree is dead and the wood has started to decay.