Oulema melanopus

Definition

A small, metallic-blue leaf beetle (Coleoptera: Chrysomelidae) native to Europe and Asia, now invasive in North America, where it is a major pest of small-grain cereals. Adults and larvae feed on the foliage of wheat, oats, barley, and rye, causing characteristic longitudinal window-pane damage by scraping away epidermal tissue. The species was described by Linnaeus in 1758 (or 1761 per some sources) and is the primary species referred to by the common name 'cereal leaf beetle.'

Etymology

Greek oulema (wound, scar) + Greek melas (black) + Greek pous (foot), referring to the dark tarsi despite the pale body of some related species; here applied to the metallic-blue cereal pest.

Example

In spring, Oulema melanopus adults migrate from overwintering sites to cereal fields, where females deposit eggs on leaf surfaces; the resulting larvae, which are often parasitized by the wasp Tetrastichus julis, skeletonize leaves and reduce grain yields.

Synonyms

• Cereal leaf beetle

Related Terms

• Chrysomelidae
• Integrated Pest Management
• Invasive species
• Oulema
• Tetrastichus julis
• crop pest
• leaf beetle
• Host plant resistance

Usage Notes

The common name 'cereal leaf beetle' is frequently applied to this species specifically, though related Oulema species can cause similar damage. In North America, biological control programs have introduced European parasitoids to manage populations. The species is sometimes confused with the related Oulema duftschmidi, with which it may co-occur; accurate identification requires examination of male genitalia or molecular markers.