Grubs of cereal beetles cause serious feeding damage to leave by scraping off their green tissue between veins of cereal crops including barley, oats, rye grass, wheat etc. Heavy infestation can cause complete skeletonization of leaves. Adult beetles also cause damage to leaves but it is not as serious as larval damage.
Adults: Adults of cereal leaf beetles are metallic bluish black colored and about 5 mm long beetles with orange colored head capsules and three pairs of legs.
Eggs: Newly laid eggs are about 1 mm long and yellowish in color but as they reach to their hatching stage they turn blackish in color. Eggs are laid singly but in pairs on the upper surface of leaves.
Grubs: Grubs of cereal leaf beetle are yellowish orange in color.
Pupae: Pupae of cereal leaf beetle are yellow in color.
Cereal leaf beetles overwinter as adults in leaf litter in the wooded areas. When temperature begins warming up early in the spring, beetles move from their overwintering sites into the fields of cereal crops. Mated females then lay eggs on the leaves. Eggs hatch within a week into small grubs that start feeding on the green leaf tissue between the veins and develop through four developing stages and become mature. Matured larvae will then fall off the plants and pupate in the soil. Then adult beetles emerge from pupae within two weeks and start feeding on plant tissues throughout the cropping season until fall. These beetles will then move into wooded areas for overwintering. Under favourable conditions, cereal leaf beetles can complete one generation in a year.