Myrmetes Marseul, 1862

Lackner, Tomáš, 2010, Review of the Palaearctic genera of Saprininae (Coleoptera: Histeridae), Acta Entomologica Musei Nationalis Pragae (suppl.) 50, pp. 1-254 : 155

Myrmetes Marseul, 1862

Myrmetes Marseul, 1862: 511 . Myrmetes: THOMSON (1867) :402; SCHMIDT (1885a):283, 318; GANGLBAUER (1899):378; REITTER (1909):290; JAKOBSON (1911):641, 648; BICKHARDT (1916 –1917):105; REICHARDT (1941): 154, 157; WITZGALL (1971): 165; MAZUR (1973): 41; KRYZHANOVSKIJ & REICHARDT (1976): 111, 121; MAZUR & KASZAB (1980): 6, 62; VIENNA (1980): 112; MAZUR (1981a): 71, 93; MAZUR (1984): 107; MAZUR (1997): 217; YÉLAMOS (2002): 245, 254; MAZUR (2004): 95.

Type species: Hister piceus Paykull, 1809 , by monotypy.

Diagnosis. Cuticle rufous, silky metallic; frontal and supraorbital striae absent; frontal disc microscopically imbricate-punctate; pronotal foveae absent; pronotal disc impunctate; pronotal hypomeron glabrous; elytra almost entirely smooth, only on apical part with shallow scattered punctures; sutural elytral stria absent; inner subhumeral stria almost complete; carinal prosternal striae united in front with lateral prosternal striae, continued onto the anterior margin of prosternum; pre-apical foveae absent; meso-metaventral sutural stria absent. All tibiae slender and flattened; protibia on outer margin with one row of short denticles, teeth absent; protarsal groove absent.

Differential diagnosis. This taxon is most similar to the genera Gnathoncus and Eremosaprinus , which are presumably its closely related taxa. From Eremosaprinus it differs by the absent sutural elytral stria, absent protibial groove and the strongly reduced, but present lateral prosternal striae. Likewise, the pronotal punctation is lacking in Myrmetes , whereas it is well developed in Eremosaprinus . By the aforementioned characters (except for the strongly reduced lateral prosternal striae that are present in both taxa) this taxon differs likewise from the genus Gnathoncus ; furthermore in Gnathoncus there is a characteristic short hooked appendix between the fourth dorsal elytral and sutural elytral striae, absent in Myrmetes .

Biology. The genus Myrmetes contains one myrmecophilous species, Myrmetes paykulli Kanaar, 1979 . It is found within the nests of Formica rufa and more rarely in the nests of several other Formica species. Very occasionally it is also found on carcasses.

Distribution. Distribution of Myrmetes covers a large part of the Palaearctic Region, from Spain to Siberia. Its presence in Central Asia reported by KRYZHANOVSKIJ & REICHARDT (1976) was later refuted ( TISHECHKIN 2002).

Species examined. Myrmetes paykulli Kanaar, 1979 .

Discussion. Myrmetes is a well-defined monophyletic taxon, supported by several autapomorphies: silky metallic rufous cuticle, absent sutural elytral stria, absent protibial groove, and peculiar shape of the sensory structures of antennal club. It shares several putative synapomorphies with genera Eremosaprinus and Gnathoncus , as mentioned earlier (see Diagnosis of the aforementioned genera for details), e.g. absent frontal and supraorbital striae and longitudinally divided tenth tergite of males. Possibly, this taxon branched off the common ancestor of these three taxa and the above-mentioned autapomorphies are simply result of the convergence of its lifestyle within ant nests. A molecular study of these three genera would be highly desirable and would undubtedly yield interesting results.