Stenolophus comma

(Fabricius, 1775)

Common Stenolophus Beetle, seedcorn beetle

Stenolophus comma is a small ground beetle commonly known as the Common Stenolophus or seedcorn beetle. Native to North America, it is primarily associated with agricultural where feed on germinating seeds and seedlings of row crops. The has been extensively studied in Iowa, where it completes two annually and overwinters as adults in soil and .

Stenolophus comma P1290060a by
xpda. Used under a CC BY-SA 4.0 license.

Stenolophus comma P1290057a by
xpda. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Stenolophus comma: /stɛˈnɒləfəs ˈkɒmə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Agricultural fields, particularly those planted with corn, oats, and soybeans. overwinter in soil, grass clumps, and . The is strongly associated with cropland environments and disturbed soils of cultivated areas.

Distribution

North America, with confirmed records from the United States (particularly Iowa), Canada, and Great Britain. Distribution records indicate presence across temperate regions of the continent.

Seasonality

emerge from hibernation in late April, with peak in early May. First adults appear in mid-July and peak in early August. Second generation adults enter hibernation by late September. Activity is concentrated during the growing season of crops.

Diet

feed on seeds and seedlings of corn (Zea mays), oats (Avena sativa), and soybean (Glycine max), causing damage by burrowing into germinating seeds and cutting seedling roots and stems. Larvae develop in soil and feed on organic matter and possibly small weed seeds.

Host Associations

Zea mays - food plant (seeds and seedlings) burrow into germinating corn seeds and cut seedling roots and stems
Avena sativa - food plant (seeds and seedlings) feed on oat seeds and seedlings
Glycine max - food plant (seeds and seedlings) feed on soybean seeds and seedlings

Life Cycle

Two occur annually. emerge from sites in late April to early May. First generation adults appear in mid-July, with peak abundance in early August. Second generation adults enter hibernation by late September. The overwinters exclusively in the adult stage, seeking shelter in soil, grass clumps, and . Larval development occurs in soil.

Behavior

exhibit surface activity patterns. They are known to burrow into germinating seeds and sever seedling roots and stems, causing characteristic damage to emerging crops. Adults seek protected microhabitats for as temperatures decline in autumn.

Ecological Role

Agricultural pest of row crops. The impacts crop establishment by damaging germinating seeds and young seedlings. Larval feeding on soil organic matter and weed seeds may contribute to nutrient cycling, though this role is secondary to its pest status.

Human Relevance

Recognized as an economically significant pest of corn, oats, and soybeans. Damage occurs during crop establishment when feed on germinating seeds and cut seedling tissues. Management in agricultural settings may be warranted when are high.

Similar Taxa

Stenolophus leconteiCo-occurring with similar , preferences, and pest status in agricultural systems. Both were studied together in Iowa and share nearly identical seasonal and damage patterns to row crops.

More Details

Taxonomic note

The has been treated under the synonym Agonoderus comma in some older literature, particularly in agricultural entomology publications from the mid-20th century.