Agriotes sputator

(Linnaeus, 1758)

Spitting Click Beetle, Common Click Beetle

Agriotes sputator is a to Europe, with established in parts of western Asia, North Africa, and an range in eastern Canada. are small (6–9 mm), dark to black with reddish-brown and legs. The , known as , are soil-dwelling agricultural pests that feed on roots and germinating seeds. The completes its in up to five years, with larvae developing through multiple growth stages before . It is considered a serious pest of cereals, potatoes, and other , and is monitored using traps baited with geranyl butanoate.

Agriotes sputator by (c) Евгений Рыбальченко, some rights reserved (CC BY), uploaded by Евгений Рыбальченко. Used under a CC-BY license.

Agriotes sputator by (c) Cosimo Costanzia di Costigliole, some rights reserved (CC BY), uploaded by Cosimo Costanzia di Costigliole. Used under a CC-BY license.

Agriotes sputator 264616949 by Cosimo Costanzia di Costigliole. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Agriotes sputator: /əˈɡraɪ.oʊtɛs ˈspju.teɪ.tɔr/

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

Identification

Distinguished from similar European Agriotes (A. sordidus, A. brevis) by : less densely punctured and more shiny between punctures. identified by pattern on abdominal : fine dense granules in belt-like regions on first 8 segments versus larger sparse granules elsewhere. Molecular identification of larvae is feasible. Larval growth stages can be determined by counting on rather than body measurements.

Images

Habitat

Natural is grassland, from which fields are frequently invaded. In Austria, most common at 300–500 m elevation in areas with 750 mm rainfall and low soil pH. In Croatia, associated with clover, alfalfa, sugar beet, and barley fields. found on flower- of umbelliferous plants.

Distribution

to Europe: widespread in UK, France, Germany, southern Sweden, Austria, Hungary, Poland, Switzerland; absent from Finland and northern parts of Norway, Sweden, Russia. South to Morocco and Algeria. East to western Siberia, Kazakhstan, Mongolia, and parts of China. West Asia: Turkey, Syria, Iran. to eastern Canada (Nova Scotia, Prince Edward Island, New Brunswick, Quebec); single unconfirmed record from Indianapolis, USA.

Seasonality

active from April/May through July/August, with peak activity in late May and early June. Most active in afternoon and evening. Adults emerge from soil in spring after . feed when soil temperature exceeds 12°C; move deeper in soil during cold or dry conditions.

Diet

are , feeding on roots, seeds, and seedlings of various plants including Poaceae (true grasses) and Plantago (plantains). feed on grass leaves and pollen.

Life Cycle

laid in batches (~100 eggs total) 2–5 cm beneath soil surface; hatch after approximately two weeks. Larval development spans 2–4 years (occasionally longer), progressing through 7–8 growth stages (not equivalent to ; up to 9 observed). may moult without growth when food is inadequate. occurs in late summer or early autumn; emerge 2–3 weeks later but remain in soil until following spring. Total (egg to egg) up to 5 years.

Behavior

are and more active in humid conditions during dry weather. Marked individuals typically move within restricted areas; maximum recorded 26 yards (23.8 m). move vertically through soil profile, descending to 1 m or more to avoid cold (<-6°C) or dry conditions. Can survive extended periods without feeding. Females exhibit searching for sites, preferring grassland or clover leys over arable land.

Ecological Role

Soil-dwelling and ; significant agricultural pest. preyed upon by birds (rooks, crows, starlings), , and parasitic . Subject to natural by fungal including Zoophthora elateridiphaga, spp., and spp.

Human Relevance

Major agricultural pest causing damage to cereals (maize, wheat, barley), potatoes, clover, alfalfa, sunflower, sugar beet, and peanut. Damage concentrated on germinating seeds and seedlings; in potatoes, tunnel into tubers. Managed through , soil , , and using . Formerly controlled with (now banned); neonicotinoids and used with mixed effectiveness.

Similar Taxa

Agriotes sordidusEuropean with similar size and coloration; distinguished by more densely punctured and less shiny between punctures
Agriotes brevisEuropean with similar appearance; distinguished by and punctation pattern
Agriotes lineatusSimilar agricultural pest; uses different component (geranyl octanoate vs. geranyl butanoate); males more mobile and pheromone traps more effective