Monotomidae

Common name
Root-eating beetles
Number of species
24
Size Range
1-5mm
Tarsal formula
4-4-4
Lobed or not

Images:

  • Monotoma bicolor
  • Monotoma brevicollis
  • Monotoma spinicollis
  • Monotoma testacea
  • Cyanostolus aeneus
  • Rhizophagus fenestralis
  • Rhizophagus picipes
Description

Despite their common name, the 23 British species of Monotomidae (formerly Rhizophagidae) are predatory, rather than root-feeding.  1.5-6mm long, elongate and parallel-sided, they have truncate elytral apices and are usually found in and around decaying organic matter.  Compost heaps, dung, birds’ nests and beneath bark are all typical habitats and two species, Rhizophagus parallelocollis Gyllenhal and R. perforatus Erichson are subterranean and can be found in coffins. 

Two species (Monotoma conicicollis Guérin-Méneville and M. angusticollis (Gyllenhal)) are myrmecophilous and the predatory R. grandis Gyllenhal is a biocontrol species introduced as a predator of the scolytid Dendroctonus micans (Kugelann) in spruce plantations.