Monotoma conicicollis Chevrolat in Guérin-Méneville, 1837
POLYPHAGA Emery, 1886
CUCUJOIDEA Latreille, 1802
MONOTOMINAE Laporte, 1840
This species is widespread and locally common in suitable habitats across the entire Northern Palaearctic region; in Europe it extends sporadically south to France, Northern Italy, Romania and Ukraine and north to the UK, Denmark and above the Arctic Circle in Scandinavia. It can be locally very common in northern regions but is local and scarce (Red-Listed in Italy) in the south where it persists mostly as a montane relic. In the UK it is generally very local and rare; there are widely-scattered records across England and Wales although it may be absent from the West Country and East Anglia, and a very few from the Scottish Highlands and Ireland. Adults have been recorded in the UK from March until October, peaking in abundance during spring and early summer, they probably occur year-round but remain under-recorded because of their cryptic lifestyle e.g. they have been recorded throughout the year in Sweden and during December in France. The species is associated with nests of various species of ants of the genus Formica L. (subgenus Formica s.str.) (Hymenoptera: Formicidae). Adults spend much of their time within the nests but occasionally occur on adjacent vegetation or debris and may swarm in warm weather. In Northern Europe they have been recorded from nests of F. rufa L., F. polyctena Foerst, F. lugubris Zetterstedt, F. uralensis Ruzsky and F. pratensis Retzius, from F. exsecta Nylander (subgenus Coptoformica Muller) and from nests (translocated from the Alps) of F. paralugubris Seifert in the Apennines (Tuscany, 1320 m.) Little is known of the biology but adults are strongly attracted to ant brood-chambers, they are ignored by ants and are known to feed on ant eggs. While the species may be under-recorded it is likely to have suffered a recent decline, along with our most widespread species of Formica (F. rufa which is mostly southern, and F. lugubris which is mostly northern) and so disturbing nests should be avoided but adults may occasionally appear while sweeping adjacent vegetation, especially in late spring and early summer.
Monotoma conicicollis 1
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.ht
2.5-3.0 mm. Body and appendages dark reddish-brown to dark red, sometimes with the forebody darker then the elytra, dorsal surface with short pale setae; randomly arranged on the head and pronotum and regularly seriate on the elytra. Head elongate with weakly diverging temples that are distinctly longer than the diameter of the eyes and long, slightly bulging cheeks, surface weakly convex and uneven but without deep fovea on the frons. Pronotum elongate, broadest across obtuse posterior angles and strongly narrowed to (usually) strongly projecting anterior angles, apical and basal margins curved, lateral teeth strongly developed, surface with two weak fovea in the basal half and often indistinctly depressed anteriorly. Elytra elongate, about 1.8X longer than wide, and gently curved from rounded shoulders which sometimes project slightly forward to almost truncate apical margins which leave the pygidium exposed, surface evenly convex and regularly striate. In males the tibiae are curved inward and have a long internal apical spur, in females they are more or less straight. Male tarsi 4-5-5, female tarsi 5-segmented.
This species may be recognised by the form of the head and pronotum. The only species likely to cause confusion is M. angusticollis (Gyllenhal, 1827), which is also associated with ants, here the head is less elongate and more narrowed in front of the eyes and the pronotum is less strongly narrowed and has weaker lateral teeth.