Ctenicera

Latreille, 1829

prairie grain wireworm, grain wireworm, click beetle

Species Guides

1

Ctenicera is a of click beetles ( Elateridae) containing several economically important agricultural pest . The genus includes the prairie grain , Ctenicera destructor, which is the most damaging wireworm species in Western Canadian cereal production. Larvae feed underground on plant stems and seeds, causing characteristic brush-like fraying damage. The genus has a Holarctic distribution with European and North American species.

Pronunciation

How to pronounce Ctenicera: /ktɛˈnɪsɛrə/

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Identification

Members of this can be distinguished from other click beetles by characteristics of the tribe Prosternini. Specific identification to level requires examination of morphological features including structure and body form. The larval stage (wireworms) are elongate, cylindrical, and hardened, with well-developed legs—features common to elaterid larvae but requiring expert identification for species-level determination.

Habitat

occur in agricultural soils, particularly in prairie grasslands and cultivated fields. Ctenicera destructor inhabits brown and black soils of the Grassland Formation in Western Canada. Larvae are found in the soil profile, with vertical distribution influenced by temperature, moisture, and food availability. have been found under soil lumps in cultivated fields and under partially dried cow manure in pastures.

Distribution

Holarctic distribution. European include C. bonomii, C. bosnica, C. cuprea, C. doderoi, C. heyeri, C. kiesenwetteri, C. pectinicornis, C. schneebergi, and C. virens. In North America, C. destructor occurs in Manitoba, Saskatchewan, and Alberta in the brown and black soils of the Grassland Formation, while C. aeripennis occurs in the grey soils of the Forest Formation. GBIF records indicate presence in Denmark, Norway, and Sweden.

Seasonality

Larvae show seasonal variations in activity and vertical distribution in response to temperature and moisture. In Western Canada, C. destructor emerge in summer with males emerging 1 or more days before females. Larval feeding activity varies with season and is directly related to temperature in the range 50–86° F. The larval stage lasts 1 to more than 2 years depending on conditions.

Diet

Larvae feed on plant stems and seeds. Ctenicera destructor larvae attack cereal crops underground, shredding stems but not cutting them off, and extract plant fluids while leaving fibers intact. They have been observed feeding on seeds of wheat, flax, barley, rye, alfalfa, crested wheatgrass, bromegrass, and rape, as well as carrot slices. Larvae attack and destroy approximately 10 times as many seeds as some other .

Life Cycle

are laid in soil with moisture content approximately halfway between field capacity and permanent wilting point. varies inversely with temperature, averaging 20 days at 68° F and 11.5 days at 86° F. The larval stage lasts from about 1 to more than 2 years at 68° F. Male larvae complete development in 9 or 10 stadia, females in 10 or 11 stadia. The pupal period lasts 2–3 weeks at 68° F. do not fly. Each female lays an average of about 200 eggs. Sex ratio is approximately 1.5 males: 1 female.

Behavior

Larvae show positive response to gravity. They aggregate at characteristic temperature ranges that vary by and season. Larvae burrow to reach moist soil before ovipositing, but lay close to the surface if surface soil is moist and underlying soil is dry. Soil cracks enhance oviposition and increase survival time. Beetles are unable to penetrate compacted field soil without cracks present. Both sexes mate only once. The is slowly dissolved during the oviposition period, with gelatinous fluid applied to eggs as they are laid.

Ecological Role

Agricultural pest causing significant damage to cereal and forage crop production. Larvae act as root and seed in soil . Their feeding activity influences plant survival and establishment in agricultural systems.

Human Relevance

Major agricultural pest in Western Canadian prairie agriculture. Ctenicera destructor is the most important in this region, causing substantial economic losses in wheat, barley, and other cereal crops. Larval feeding destroys seeds and damages underground stems, reducing crop establishment and yield. Management requires understanding of soil conditions that influence oviposition and larval survival.

Sources and further reading