Colydium

Fabricius, 1792

cylindrical bark beetles

Species Guides

4

Colydium is a of small, cylindrical bark beetles in the Zopheridae, comprising approximately five described in North America and three in the Western Palearctic. These beetles are morphologically adapted for life under bark, with slender, bodies and costate . At least one species, C. elongatum, has been sequenced at the level, revealing a of 450.16 Mb with 10 chromosomal pseudomolecules. The genus includes both saproxylic species associated with wood decay and stored product pests.

Colydium lineola by (c) Victor Engel, some rights reserved (CC BY), uploaded by Victor Engel. Used under a CC-BY license.Colydium lineola by (c) skitterbug, some rights reserved (CC BY), uploaded by skitterbug. Used under a CC-BY license.Colydium lineola by (c) Victor Engel, some rights reserved (CC BY), uploaded by Victor Engel. Used under a CC-BY license.

Pronunciation

How to pronounce Colydium: /kəˈlɪdiəm/

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

Identification

Colydium are distinguished by their cylindrical, slender body form and , nearly glabrous dorsum with costate (ridged) . Western Palearctic species can be separated using morphometric characters and genetic analysis; an illustrated key is available for this region. Species-level identification requires examination of subtle morphological differences; cryptic species have been documented.

Images

Habitat

Under bark of dead or dying trees; in galleries of other wood-dwelling insects. At least one (C. castaneum) has been documented in stored product environments.

Distribution

North America (five described : C. glabriculum, C. lineola, C. nigripenne, C. robustum, C. thomasi); Western Palearctic (Europe and North Africa, including C. elongatum, C. filiforme, and C. noblecourti). GBIF records from Denmark, Norway, and Sweden.

Diet

Facultative on or young larvae of insects, or commensal feeding on fungi and decaying organic matter.

Behavior

Morphologically adapted for movement under bark; lives in galleries of other wood-dwelling insects. C. castaneum has been observed in traps baited for Rhyzopertha dominica, with visual cues playing a primary role in trap orientation.

Ecological Role

Saproxylic contributing to wood-decay processes in forest .

Human Relevance

C. castaneum is a stored product pest captured incidentally in traps deployed for monitoring Rhyzopertha dominica in cereal warehouses. C. elongatum sequencing provides genomic resources for the Zopheridae.

Similar Taxa

  • Colydium elongatumType for sequencing; distinguished by specific morphometric and genetic characters from other Western Palearctic species
  • Colydium filiformeCo-occurs with C. elongatum in the western Palearctic; separated by morphological and genetic analysis
  • Colydium noblecourtiRecently described European ; cryptic and requiring genetic/morphometric analysis for separation from

Sources and further reading