Metrius contractus
This record describes Metrius contractus (species). Recorded family: Carabidae. Recorded order: Coleoptera.
Identification and Appearance
This species has a coastal distribution while the other species, M. explodens , is only known from Idaho. ( 3 ) Three subspecies recognized. ( 3 ) Secretes defensive chemicals (quinone-based and hot, like bombardier beetles) as a frothy mixture that can either be held at the rear of the body or channeled forwards along special tracts. This is perhaps a primitive state among beetles with similar defensive chemicals. See Eisner et al. ( 4 ) for more detail.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Coleoptera (Beetles)
- Suborder
- Adephaga
- Family
- Carabidae (Ground Beetles)
- Subfamily
- Paussinae
- Tribe
- Metriini
- Genus
- Metrius
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
Lindroth notes taking the nominate subspecies north of San Francisco "along a steep roadside of very fine sand in dry, half-shaded position (mixed forest) together with the burrows of Omus californicus ."
About Primitive Winged Insects: the wider group
Order-level background for Coleoptera, the group containing Metrius contractus. Species-specific details appear above.
Group overview
Coleoptera is the largest order of insects with over 400,000 described species, representing ~25% of all known animal species and ~40% of all insects. In the U.S. alone, nearly 30,000 beetle species have been identified.
Ecological role of the group
Beetles are prominent decomposers, especially in forests, breaking down dead wood and recycling nutrients. As predators, they reduce populations of pest insects. Many species are also important pollinators of flowering plants.
Economic and practical significance of the group
Beetles have major economic significance: leaf beetles (Chrysomelidae) and weevils (Curculionoidea) are among the most destructive agricultural pests globally, costing billions annually, while predatory species like ladybugs provide natural pest control.
Recorded sources for this group: Britannica, Smithsonian, NCSU Entomology. Imported estimates may describe particular regions or reporting periods.
Photos of Metrius contractus (5)
Photo credits: Contributed by Eric R. Eaton; Additional contributions by Bbarnd
Frequently Asked Questions About Metrius contractus
What is Metrius contractus?
Metrius contractus is a species in the family Carabidae, within the order Coleoptera.
How do you identify Metrius contractus?
This species has a coastal distribution while the other species, M. explodens , is only known from Idaho. ( 3 )
Where is Metrius contractus found?
Habitat: Lindroth notes taking the nominate subspecies north of San Francisco along a steep roadside of very fine sand in dry, half-shaded position (mixed forest) together with the burrows of Omus californicus .