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Larger Elm Leaf Beetle (Monocesta coryli)

Detailing the identifying qualities of the Larger Elm Leaf Beetle, including physical features and territorial reach.

 Updated: 8/29/2017; Authored By Staff Writer; Content ¬©

  Larger Elm Leaf Beetle  
Picture of Larger-Elm-Leaf-Beetle

Some are orange, some are yellow, some have spots, some do not, and sometimes Larger Elm Leaf Beetles are considered a small pest.

Individual Larger Elm Leaf Beetles have a variety of forms. The most recognizable version is yellow with two large brown-black spots on the bottom of the elytra (wing covering) and two lighter spots by the head. As their name suggests, they are found on elm trees where there larval form devours leaves. Hazel, pecan, and birch trees are also a host plant. This species rarely defoliates a large area, but occasional outbreaks happen. It is not as troublesome as other elm-feeding beetles like the Elm Leaf Beetle. Signs of caterpillar presence include the skeletonizing of leaves and a growing brown appearance to foliage, almost as though the leaves were scorched.

Adults stay in the canopy and females lay fertilized eggs on the bottom of leaves. Newly hatched larvae are a metallic red-brown color and they immediately start chewing the fleshy parts of leaves, leaving the thick veins behind. When ready to pupate, they move down the tree into soil and stay there through winter. Adults emerge in the spring. Because only one generation is produced each year, they rarely wreak havoc on a significant scale. When populations are large, however, they are considered a more serious pest. Natural controls like parasites and predators reduce the population the following year, stopping outbreaks from becoming widespread.

Larger Elm Leaf Beetles are found most often in hardwood forests and woodlands that have elm trees in abundance.

Larger Elm Leaf Beetle Information

Category: Beetle
Common Name: Larger Elm Leaf Beetle
Scientific Name: Monocesta coryli

Taxonomy Hierarchy

 Arrow graphic Kingdom: Animalia
  Arrow graphic Phylum: Arthropoda
   Arrow graphic Class: Insecta
    Arrow graphic Order: Coleoptera
     Arrow graphic Family: Chrysomelidae
      Arrow graphic Genus: Monocesta
       Arrow graphic Species: coryli

Size, Identifying Tags and Territorial Reach

Size (Adult, Length): Size (Adult, Length): 10 mm to 16 mm (0.39 inches to 0.624 inches)
Identifying Colors: yellow, brown, orange, black, blue
Additional Descriptors: bands, spots, long, flying

North American Territorial Reach (Though Not Limited To): Alabama; Delaware; Florida; Georgia; Indiana; Kentucky; Louisiana; Maryland; Massachusetts; Michigan; Mississippi; North Carolina; Ohio; Pennsylvania; South Carolina; Tennessee; Virginia; West Virginia

A Note About Territorial Reach: Keep in mind that an insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above. Insects are driven by environmental factors, food supplies and mating patterns and do not nescessarily work within hard-and-fast territorial lines like we humans do.

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