|
The cereal leaf beetle (Oulema melanopus)
can be found on new corn shoots, but the insect is most common on cereals such
as wheat, oats, barley, rye, millet and wild grasses. The beetle is mostly
blue-black in color, with an area of deep red just behind the head. The legs are
dull orange. When the beetle became economically damaging during the 1960's, it
was discovered that insecticides were without success, but when natural enemies
of the beetle were discovered, imported, and released in affected fields, the
cereal leaf beetle came under control.
Overwintering in fields of wild grasses, in the
spring it enters cultivated fields and deposits eggs. The larvae emerge and
cover themselves with their own excreta in order to mimic the droppings of birds
or other insects. They usually appear as shiny, wet lumps adhered to the surface
of leaves. They gorge on the plants, then drop off and pupate in the soil for
about 3 weeks, emerging full-grown to continue feeding on the plants. Both adult
and larva prefer young plant shoots or areas of new growth on established
plants. Damage from cereal leaf beetle is apparent when the tips of leaves turn
white and the leaves develop white stripes or slits where the beetle has
consumed a strip. A field with extensive damage will look frosted or
whitewashed.
|
|
