Agrotis

Ochsenheimer, 1816

cutworms

Species Guides

19

Agrotis is a large of noctuid containing numerous , many of which are significant agricultural pests. The genus was established by Ferdinand Ochsenheimer in 1816. Several species have been documented as extinct. Larvae are known as cutworms due to their habit of severing plant stems at or near the soil surface. The (Agrotis infusa) was historically important as a seasonal food source for Australians.

Agrotis ruta by (c) Doug Macaulay, some rights reserved (CC BY), uploaded by Doug Macaulay. Used under a CC-BY license.Agrotis antica by no rights reserved, uploaded by Ben Keen. Used under a CC0 license.Agrotis by (c) Donald Hobern, some rights reserved (CC BY). Used under a CC-BY license.

Pronunciation

How to pronounce Agrotis: /əˈɡroʊtɪs/

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

Identification

Distinguished from similar (Euxoa, Feltia) by wing venation pattern (hindwings with 3 and 4 from ) and genitalic characters. Palpi structure with obliquely porrect second joint and prominent third joint is diagnostic. Distinguished from other Noctuinae by combination of non-crenulate forewing outer margin and absence of thoracic/abdominal tufts. -level identification requires examination of genitalia.

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Habitat

Agricultural fields, grasslands, weedy areas, and open . Larvae favor loose, sandy, or dusty soils for subterranean . prefer grassy and weedy fields for -laying. Some species associated with specific soil types (e.g., pale western cutworm in loose, sandy, dry soils).

Distribution

Worldwide distribution with records from North America (including Vermont), Europe (Denmark, Norway, Sweden), and other regions. Specific distributions vary by ; some species have restricted ranges while others are widespread agricultural pests.

Seasonality

activity typically , with peak and oviposition during night hours. Oviposition occurs primarily at night, with bimodal distribution pattern highest in first part of night. Moonlight above 0.1 lux suppresses -laying activity. Larval feeding begins in spring; some overwinter as larvae, others as pupae or adults. Multiple per year possible depending on species and climate.

Diet

Larvae feed on diverse plant material including seedlings of grains (sorghum, wheat, maize), vegetables, and other crops. Feeding habit varies: surface-feeding cut stems at or slightly below soil level; climbing species feed on aboveground plant parts; subterranean species feed on underground plant parts including seedling roots.

Life Cycle

laid in soil or on stems/leaves, hatching in 2–14 days. Larval development through multiple instars, with feeding period extending from spring to early summer. Larvae characteristically hide in soil or plant debris during day, emerge to feed at night. in soil. stage variable by : larvae, pupae, or . Some species complete in 30–40 days with multiple ; others have single generation with extended .

Behavior

activity pattern in . Larvae exhibit negative , remaining hidden in soil or debris during daylight hours. Characteristic defensive : larvae curl into C-shape when disturbed. Subterranean burrow in soil; surface species hide under plant residue. Adult oviposition suppressed by moonlight above 0.1 lux, with effect more pronounced at higher temperatures. Bimodal oviposition pattern with peaks in early night hours.

Ecological Role

Larvae function as primary consumers in soil and ground-level . Serve as prey for ground-foraging birds, rodents, predatory beetles, and . Some (e.g., ) historically constituted significant seasonal food resource for vertebrate and human .

Human Relevance

Major agricultural pest ; larvae known as cutworms cause substantial economic damage to grain crops (sorghum, wheat, maize), vegetables, and seedlings. Damage mechanism: severing plant stems at or near soil surface, killing seedlings and reducing stand establishment. Management relies on cultural practices (weed control, seedbed preparation), applications (often timed for late afternoon effectiveness), and . Insecticide resistance documented in some . Bt maize provides effective control for some . Historical significance: (Agrotis infusa) was important seasonal food for Australians.

Similar Taxa

  • EuxoaAlso contains ; distinguished by different wing venation and genitalic characters, and typically has different palpi structure.
  • FeltiaFormerly included now placed here (e.g., Feltia subterranea, Feltia repleta); separation based on genitalic and wing venation differences.
  • HelicoverpaLarval damage can appear similar (cut plants), but larvae have different and ; have distinct wing patterns and different genitalia.

More Details

Taxonomic changes

Several formerly placed in Agrotis have been transferred to other based on revised classification: Agrotis dolli to Eucoptocnemis dolli, Agrotis repleta to Feltia repleta, and Agrotis subterranea to Feltia subterranea.

Research significance

Agrotis ipsilon has been used as model organism for studies on insect olfaction, response, and photoperiodic time measurement, contributing to understanding of seasonal mechanisms in insects.

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