Satrapister nitens Bickhardt, 1912

Lackner, Tomas, 2016, Satrapisternitens Bickhardt, 1912: redescription and tentative phylogenetic placement of a mysterious taxon (Coleoptera, Histeridae, Saprininae), Deutsche Entomologische Zeitschrift 63 (1), pp. 1-8 : 2-4

Taxon classification Animalia Coleoptera Histeridae

Satrapister nitens Bickhardt, 1912 Figs 1, 2, 3, 4-13

Satrapister nitens Bickhardt, 1912: 232

Satrapister nitens Mazur (1984): 64; Mazur (1997): 232; Mazur (2011): 189.

Type material examined.

Lectotype (designated here), ♂, glued on its side on a triangular mounting point, except for pretarsus all other tarsi missing, both antennae, left mandible missing, both hind legs missing, propygidium and pygidium dismembered, separated from the rest of the abdominal segments and glued to the mounting card separately from the specimen, right elytron wholly longitudinally cracked, with dismembered male genitalia glued also to the same mounting card as the specimen, with following labels: "in Peru guano" (written); followed by: “Type” (brick-red label, written); followed by: " Satrapister / nitens / n.gen. n. sp. / Bickh" (dark green, barely legible written label); followed by: "Coll. Veth" (printed); followed by: “Type” (red label, printed); followed by: "LECTOTYPE / Satrapister nitens / Bickhardt, 1912 / des. T. Lackner 2015 " (red label, written) (NCB). Syntype, ♀, designated as lectotype by G. Arriagada in 1990, but apparently never published, body and head glued on a triangular point, with five legs, both mandibles, two antennal scapes and one antennal club dismembered and glued in Canada balsam on a separate mounting card, with pygidium and dismembered female genitalia glued in Canada balsam on another mounting card under the former one, followed by: "in Peru guano" (written); followed by: “Type” (brick-red card, written); followed by: " Satrapister / nitens Bickh. / n.gen., n. sp." (written); followed by: " Satrapister / Bickh." (written); followed by: " nitens / Bickh." (written); followed by: "Zool. Mus. / Berlin" (printed); followed by: " Satrapister ♀ / nitens Bickh. / Lectotype / G. ARRIAGADA DET 1990" (black/red framed written-printed label) (ZMHUB). Note. This species was described based on two specimens. Bickhardt (1912) apparently did not check the sex of specimens. Although Arriagada examined the specimen from ZMHUB and furnished it with a lectotype label, his designation has never been published. Since the specimen housed in ZMNHUB is a badly damaged female and the second specimen in NCB is a male that is in somewhat better condition I designate the male from NCB as the lectotype here. The second specimen, housed in ZMHUB therefore bears the status of a syntype.

Additional material examined.

PERU: 2 ♂♂, Isla Don Martín, 15.ii.1955, Coll. M. Peña (MUSM). 1 ♀, Isla de Pescadores [=Isla Grande], 5.viii.1934, collector illegible (SENASA).

Description.

Body (Figs 1-2) PEL: 1.50-1.70 mm; APW: 0.625-0.65 mm; PPW: 1.00-1.125 mm; EW: 1.25 mm; EL: 1.00 mm; colour (including body appendages) light brown to castaneous, antennal club amber-coloured. Clypeus flat, with scattered punctuation; labrum with wide median depression, with two long labral setae arising from each labral pit; mandibles rather slender, left mandible slightly longer than right, both mandibles pointed apically, sub-apical tooth on left mandible situated approximately in mandibular mid-length, obtuse; vague vestiges of frontal stria present anterad eyes, frontal + supraorbital striae otherwise absent; frontal disc flat, with scattered punctuation, punctures separated by several times their diameter, on posterior margin with distinct fovea medially; occipital stria fine, complete. Antennal scape slightly thickened, antennal club round, sensory structures of antennal club (Fig. 3) in form of one stipe-shaped vesicle situated under round sensory area on internal distal side of the antennal club dorsally, bridge-like connected with another sensory area. Antennomeres 1-8 with distinct setae. Eyes small (reduced?), flattened, invisible from above; surface above eyes on frontal lateral margins with distinct regular microscopic setae.

Pronotal hypomeron punctate, with distinct regular microscopic setae, lateral pronotal margins (Fig. 1) on basal two-thirds almost sub-parallel, on apical third narrowing, anterior pronotal angles obtuse. Pronotal disc laterally with sparse, rather deep elongate punctures separated by their own to several times their diameter; medially disc with scattered microscopic punctuation. Marginal pronotal stria thin, but carinate and complete; pronotal base with a vague row of tiny punctures. Scutellum small, triangular.

Elytral epipleuron with several irregular wrinkles and few punctures, otherwise smooth; marginal epipleural stria fine, complete, marginal elytral stria carinate and complete; apical elytral stria obliterated on half its length. Oblique humeral stria deeply impressed on basal elytral fourth; in one specimen a median fragment of inner subhumeral stria as well as a basal fragments of elytral striae 1-2 present; in rest of specimens all other elytral striae, except for short basal fragment of fourth dorsal elytral stria that is basally connected to almost complete sutural elytral stria completely lacking. Elytral disc with scattered punctures separated by several times their diameter.

Propygidium and pygidium with punctuation similar to the elytra, but punctures deeper and denser, separated approximately twice their diameter.

Prosternal process (Fig. 2) on apical margin with distinct, rather long amber setae; marginal prosternal stria present as a median fragment; carinal prosternal striae very weak, usually present only between procoxae, next evanescent (in two specimens intermittent to almost complete); lateral prosternal striae widely divergent anteriorly and ending in apical sulcus; prosternal foveae absent; prosternal keel even, rounded, impunctate, alutaceous.

Mesoventrite (Fig. 2) sub-trapezoid, convex, sparsely punctuate, marginal mesoventral stria thin, weak; meso-metaventral sutural stria absent; metaventrite almost smooth, only with several scattered punctures becoming denser along metaventral base; lateral metaventral stria straight, thin, vaguely impressed, shortened; lateral disc of metaventrite with dense deep, almost confluent punctures fringed with long amber setae; metepisternum with similar punctuation.

First visible abdominal ventrite vaguely striate laterally, disc almost glabrous, only with scattered microscopic punctuation.

Legs: protibia slightly dilated, with 9-11 low teeth topped by rather long thin curved denticles diminishing in size in proximal direction, protarsal groove shallow, protibial spur short and stout, growing out from apical protibial margin, further characters of protibia not examined. Mesotibia on outer margin with a row of low teeth topped by long, slender amber-coloured denticles, setae of outer row dense and rather long; setae of median row finer and shorter; on anterior face of mesotibia another row of shorter dense amber denticles present, mesotibial spur stout and well-developed; metatibia slightly longer than mesotibia, denticles on outer metatibial margin more closely-set; metatarsal claws short, bent, about half-length of terminal metatarsal segment; other characters of legs not examined.

Male genitalia: eighth sternite (Figs 4-5) longitudinally divided medially, apically with tiny velum topped by several microscopic setae; eighth tergite inwardly arcuate apically; eighth sternite and tergite fused laterally (Fig. 6). Ninth tergite (Figs 7, 9) longitudinally separated medially; tenth tergite (Fig. 8) apically with lateral processes; spiculum gastrale (Fig. 10) apically separated into two arms; base distinctly triangular. Aedeagus (Fig. 12) with rather short phallobase, ratio phallobase: tegmen approximately 1:5; tegmen sub-parallel, faintly dilating apically; apex with pores and pseudo-pores; parameres fused apically and on their basal 2/5; aedeagus laterally curved ventrad (Fig. 13).

Cladistic analysis.

Results of the tree reconstruction analyses are shown in Figure 14A. Heuristic search resulted in 1026 equally parsimonious trees of tree length (TL) = 582, CI = 0.33, RI = 0.66. The strict consensus of the equally parsimonious trees had the following characteristics: TL = 701, CI = 0.29, RI = 0.57. The strict consensus tree is mostly resolved, but bootstrapping resulted in low support values for most of the recovered branches.