Pseudonomaretus Roeschke 1907

Kavanaugh, David H. & Angel, Kathleen W., 2015, A Taxonomic Review of the Northwestern Nearctic Subgenus Pseudonomaretus Roeschke 1907, including Description of the New Species Scaphinotus hoodooensis (Coleoptera: Carabidae: Cychrini) from the Bitterroot Mountains of Montana, Proceedings of the California Academy of Sciences 62 (14), pp. 381-396 : 384

Subgenus Pseudonomaretus Roeschke 1907

Pseudonomaretus Roeschke 1907:154 . Type species: Cychrus relictus G. H. Horn 1881 ; designated by Casey 1914:30.

RECOGNITION.— Throughout the taxonomic history of this subgenus, it has proven difficult to provide a suite of diagnostic features that are shared by all of its members; and the combination of features shared by members of our new species confounds the problem even more. Keys provided by Ball (1960), Gidaspow (1973), and Ball and Bousquet (2001) all required Pseudonomaretus to key out in two separate couplets. Hatch (1953) cited the combination of moderately widened genal projections, distinct elytral striae and broadly dilated male protarsi as characteristic of members of Pseudonomaretus . However, he dealt only with Scaphinotus species of the Pacific Northwest and so did not have to distinguish Pseudonomaretus members from those of Maronetus Casey (1914) or Nomaretus LeConte (1853) , at least some members of which share these same features. In his treatment of Scaphinotus, Lindroth (1961) avoided the problem entirely by keying specimens directly to species, without reference to subgenera.

Adults of all species in this subgenus share the following combination of character states: head with frons smooth, convex, not cristate; genae expanded laterally as a narrow shelf in front of and below each eye, each with a distinct notch in the shelf in line with the anterior margin of the eye; labrum deeply emarginate, with four setae at base between lateral lobes; labial palpomere 2 with three or more setae; pronotum with base impunctate; elytral epipleura impunctate or with only a few scattered, shallow, vaguely defined depressions; anterior tarsus of male with tarsomeres 1 to 3 broadly expanded laterally and with dense pads of disco-type ( Stork 1980) adhesive setae ventrally. This combination of features is not sufficient to distinguish all members of Pseudonomaretus from all members of all other subgenera. There are several additional features shared by members of most but not all species of Pseudonomaretus , and these are presented and considered in the Discussion section below. Combined, the features shared by all members plus those shared by most members represent a character complex that is unique to this taxon among cychrine genera and subgenera. So characterized, Pseudonomaretus is a classic example of a “polythetic taxon” as discussed by Mayr (1969).