Apostenolinus Bernhauer, 1934

SMETANA, ALEŠ & DAVIES, ANTHONY, 2000, Reclassification of the North Temperate Taxa Associated with Staphylinus Sensu Lato, Including Comments on Relevant Subtribes of Staphylinini (Coleoptera: Staphylinidae), American Museum Novitates 3287, pp. 1-1 : 1-

Apostenolinus Bernhauer, 1934

TYPE SPECIES: Apostenolinus cariniceps Bernhauer, 1934 .

COMMENTS: In addition to its large size (23 mm), the single species of this genus may be easily recognized by the following character states: ( 1) head, pronotum, and elytra dark bluish; ( 2) outer four segments of antenna whitish­yellow; and ( 3) pronotum markedly narrowed anteriad toward narrow head, which is distinctly attenuated posteriad.

Further character states include: mandibles rather long and slender, with acute apices, medial margin of each with only one tooth, tooth on left mandible short, broadly truncate, tooth on right mandible broadly triangular, rather acute; eyes slightly shorter (not longer, as stated in the original description) than tempora (ratio 0.86); puncture bearing postgenal macroseta situated much closer to posterior margin of eye than to posterior margin of head; superior line of pronotal hypomeron moderately and rather gradually deflexed ventrad at about apical fourth of length of pronotum, joining inferior line of pronotal hypomeron well before anterior angles, anterior portion of superior line situated only moderately below basal portion in lateral view; pronotal epimeron absent; surface of pronotum with microsculpture of fine, short, mostly oblique striae; mesosternum without transverse carina; punctation of elytra very dense, corneous; surface with dense, fine, rugose microsculpture, appearing dull; abdominal tergites with posterior basal line very gently bisinuate.

The status of this taxon cannot be established with certainty at present. The only known male specimen of A. cariniceps is somewhat damaged (see below), and it has lost all mouthparts (including mandibular prostheca) due to dermestid damage. Bernhauer (1934: 9) established it as a subgenus of Staphylinus . The general habitus of the species is certainly conspicuous, as noted already by Bernhauer (loc. cit.), mainly due to the combination of the narrow head and the pronotum markedly narrowed anteriad. Bernhauer (loc. cit.) described the pronotum as ‘‘vor dem Schildchen mit zwei grossen, langen Längseindrücken.’’ The impressions are in fact somewhat irregular, and since the pronotum is definitely cracked anteriorly, there is a distinct possibility that the pronotum may have been exposed to excessive pressure that caused not only the cracking but also the two irregular impressions; in oth­ er words, the impressions may be artificial and not characteristic of the species.

Due to the configuration of the pronotum, particularly the development of the superior and inferior lines, Apostenolinus is not a member of the ‘‘ Dinothenarus – Staphylinus ’’ lineage. The impressions on the head and pronotum (if really present on the latter) are likely an autapomorphy. Apostenolinus is considered here as a separate genus only tentatively, pending the availability of more specimens for study.