Monotoma bicolor Villa & Villa, 1835
POLYPHAGA Emery, 1886
CUCUJOIDEA Latreille, 1802
MONOTOMINAE Laporte, 1840
Native to the Western Palaearctic region, this species has been transported with trade and is now Holarctic in distribution; it is also recorded from the Caribbean region, sub-Saharan Africa, and has become established in Australia and New Zealand. The European distribution extends from Spain to Greece and north to the UK and the Arctic Circle in Sweden; it is known from most of the Mediterranean and Atlantic islands and is widespread in North Africa. To the east it extends to the pacific coast of Russia, China and Japan. In the UK it is locally common in south-eastern England and East Anglia, very local in Wales and the midlands, and there are sporadic records further north into Southern Scotland. Adults occur among decaying vegetation of all kinds; they are sometimes common among undisturbed litter in barns and stables, or in compost or grass cuttings in domestic gardens etc., but they might be found more generally among damp litter etc. in any not too wet situation. Adults are active year-round; they peak in abundance during the spring and again in September and October. Little is known of the biology but, typical of many members of the genus, oviposition and development probably occur among decaying vegetation during spring and summer. Sifting through decaying plant material or taking samples for extraction are the easiest ways to find the adults, and they are usually common where they occur.
1.9-2.5 mm. Elongate and rather parallel-sided, forebody dark brown, sometimes almost black, clypeus, elytra and appendages pale to yellowish-brown. Dorsal surface with fine elongate and pale setae, these forming distinct elongate rows on the elytra. Head with protruding and proportionally large eyes, temples sharply angled and about half the length of the eyes, lateral margin between the eyes and antennal insertions angled. Frons with large, deep and almost confluent punctures, slightly raised but without longitudinal impressions. Antennae 11-segmented with a fused 2-segmented club. Pronotum slightly elongate, 1.05-1.15X longer than wide, lateral margins weakly curved to almost parallel-sided, posterior angles distinct but lacking distinct calli, anterior angles distinctly but only weakly protruding, surface with two fovea in the basal half only. Elytra smoothly curved from rounded shoulders to separately-rounded apical margins, punctures forming longitudinal series from the suture but often becoming confused laterally. Femora long and robust, tibiae gradually expanded from the base and with tiny, hardly noticeable, spurs on the apical margin. Tarsi 5-segmented in females, 5-5-4 in males; basal segments short and weakly lobed, terminal segment longer than the others combined. Claws smooth and weakly toothed at the base.
Monotoma bicolor 1
Monotoma bicolor 2