NPIPM:Seedcorn beetles
Authors: Buyung Hadi, Robert Wright, R. Jeff Whitworth, Holly Davis, and J.P. Michaud
Identification
Seedcorn beetles are members of ground beetle family (Carabidae). Two species of seedcorn beetles may be found in the field: the seedcorn beetle (Agonoderus lecontei) and the slender seed corn beetle (Clivinia impressifrons).
The seedcorn beetle is brown or yellow brown in color with a broad black stripe on each wing cover. The slender seedcorn beetle is uniform chestnut brown or reddish brown, without black stripes on the wing covers, slightly longer but narrower than the seedcorn beetle. Both beetles are about 0.25 in (6 mm) long.
Life Cycle and Seasonal History
Seedcorn beetles overwinter as adults or pupae in the soil. The adults feed on corn seeds and may destroy the seed endosperm. The seeds fed on by seedcorn beetles may fail to germinate, thus reducing the stand in the process. Both species of seedcorn beetle produce two generations per year. Conditions that cause slow or poor germination such as cool and wet soil increases the probability of damage due to seedcorn beetle feeding. Poor closure of the seed furrow also is favored by planting into wet soils, and may increase access and injury to the germinating seed by seedcorn beetles.
Plant Injury and Damage
The adult beetles feed on seeds. Economic damage maybe caused by reduced plant stand. Seedcorn beetles are considered sporadic pests. The larvae of these beetles are predators of other insects and do not feed on plants.
Management Approaches
Use of good quality seed and insecticidal seed treatments ensure good germination and protect against injuries due to seedcorn beetle feeding.
Other Online Resources
Insects That Attack Seeds and Seedlings of Field Crops - University of Nebraska
Seedcorn beetle - Kansas State University
Radcliffe's IPM World Textbook, Maize Insect Pests in North America
