Oulema melanopa

1. Symptoms: Adult beetles are 4-5 mm long, have a black head, light brown thorax, and a shiny blue-green wing cover with parallel lines of small dots (picture top left). Larvae are a dull to bright yellow color, but soon take on the appearance of a slimy, globular, black mass due to the mound of fecal material they produce and accumulate on their backs (picture top right & bottom left). The most prominent symptom of cereal leaf beetle infestations is the distinct, longitudinal stripes on leaves (picture bottom right); these stripes are produced by the feeding of adult beetles and of larvae.
2. Life Cycle: The insect produces one generation per year. Adults begin their feeding activity in the spring. They lay yellow eggs, either singly or in small chains, covering them with a sticky film that holds the eggs in place. Pupation takes place in the soil and the adults emerge in summer. Adults overwinter underneath plant debris on the soil surface, in leaf sheaths and ears of standing maize or under the bark of trees.
3. Hosts/Distribution: Cereal leaf beetles can be a problem on fall-sown cereals. Wheats with hairy leaves are affected less.
4. Importance: Significant yield losses can occur in winter wheat and fall-sown spring wheat. Yield losses of from 14% to more than 25% have occurred with natural infestations.