Larvae are dark and slug-likein appearance. Their skin is yellow or yellowish brown and covered by amass of slimy, dark, fecal material. Clusters of adult beetles overwinterin grass stems, grain stubble, cracks, and fenceposts.
Adults prefer spring grainsto winter wheat.
Within two weeks the beetles quit feeding and the females begin layingeggs. One female may lay up to 300 eggs, depositing each egg on its side,singly or in rows of three or four. Normally, eggs are placed on the upperleaf surface near the midrib of the leaf. Eggs hatch in four to 23 days,depending on temperature. After feeding for 10 to 14 days, the mature larvaecrawl down the plant into the soil to pupate.