Keep an Eye Out for Cereal Leaf Beetle

Scout now for infestations of cereal leaf beetle in small grain fields. The larval stage feeds on the leaves and fields appear white if heavily infested.
Keep an Eye Out for Cereal Leaf Beetle - Articles

Updated: May 11, 2016

Keep an Eye Out for Cereal Leaf Beetle

Mourad Louadfel, Bugwood.org

Cereal leaf beetles larvae continue to be active in wheat and oat fields across state (barley and rye can be infested occasionally). Infestations are difficult to predict and can be very patchy, so scouting is the key to identifying local populations that might need to be managed. Cereal leaf beetle larvae can be mistaken for slugs because they can look small, dark and shiny, but if you look closely and see legs, you are not dealing with slugs (Figure 1).


Figure 1: Cereal leaf beetle larvae

Moreover, slugs tend only to be nocturnal, so slimy creatures out during the day in small grains have a good chance of being cereal leaf beetle larvae. If young larvae are detected at populations exceeding the economic threshold, cereal leaf beetle is easily controlled with insecticides, but larger larvae are more difficult to control and cause more damage, particularly if they feed on the flag leaf. Insecticide treatments are warranted if populations exceed the economic threshold of one larva over 0.13 inches long per stem over a field or a portion of a field. A recently published fact sheet provides more details on their life cycle and some images of adults, larvae, and their damage. For insecticide options, please consult Penn State's Agronomy Guide .

Authors

Insect ecology Plant-insect interactions Conservation biological control Chemical ecology Gall insects

More by John Tooker, Ph.D.