In general, barley is more advanced in the spring and less attractive to egg -laying adults. Newly emerged larvae will feed voraciously for 10 days to 3 weeks. Summer adults emerge during late June and early July, feed on corn and wild grasses, then enter a summer dormancy. Only one generation occurs per year. Both larvae and adults feed on the upper leaf surfaces of wheat and oats.
Adults feed between the leaf veins, resulting in longitudinal streaks on the leaves.
Sampling and Decision Making Begin sampling fields in early April as soon as adult beetles are observed. Count the number of eggs and larvae per stem and estimate the percent defoliation. If only eggs are found, the field should be re-sampled at a later date when eggs have hatched and larvae are detected. Research from Virginia and North Carolina indicates that the greatest damage can occur between flowering and the soft dough stage. A number of introduced parasites have been used to keep populations below an economic level.