Loncovilius Germain, 1903

Reyes-Hernández, José L., Hansen, Aslak Kappel, Shaw, Josh Jenkins & Solodovnikov, Alexey, 2024, Phylogeny-based taxonomic revision and niche modelling of the rove beetle genus Loncovilius Germain, 1903 (Coleoptera: Staphylinidae: Staphylininae), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (1), pp. 1-42 : 11-24

Genus Loncovilius Germain, 1903 sensu nov.

( Figs 4–15)

Loncovilius Germain 1903: 439 (original description; species included: semiflavus , lividipennis ); Bernhauer and Schubert 1916: 417 (subgenus of Quedius ); Blackwelder 1952: 226 ( type species Loncovilius semiflavus , by subsequent designation); Coiffait and Sáiz 1966: 401 (characters; key to Chilean species); Sáiz 1971: 387, 389 (notes on biogeography; notes on phenetic relationships).

Type species: Loncovilius semiflavus ( Fairmaire and Germain 1862) .

Included species: Loncovilius barclayi sp. nov., L. cantharoides sp. nov., L. carlsbergi sp. nov., L. edwardsianus (Korge, 1963) , L. germaini ( Scheerpeltz, 1933) , L. hammondi sp. nov., L. impunctus sp. nov., L. lividipennis ( Fairmaire and Germain, 1862) , L. semiflavus ( Fairmaire and Germain, 1862) , and Loncovilius variabilis sp. nov..

Diagnosis: Loncovilius can be distinguished from all other genera in Amblyopinini based on the combination of the following characters: frontoclypeal (epistomal) suture complete ( Fig. 7C–E); basisternum flat, with few punctures, without pair of macrosetae; with rounded flexible postcoxal hypomeral extension or process; two short empodial setae on each tarsomere 5; ventral side of meso- and metatarsi in males and females with pale adhesive setae ( Fig. 7F); abdomen without protergal glands; all tergites without posterior transverse basal carina (PTBC); lateral tergal sclerites IX at least slightly longer than tergite VIII. Free-living; females distinctly larger than males.

Description: Frontoclypeal (epistomal) suture complete; neck constriction fully developed; neck moderately wide; nuchal ridge latero-ventrally extended anteriad beyond level of postgenal ridge, merged with, or coming very close to, infraorbital ridge; dorsal basal ridge absent; ventral basal ridge extending more or less parallel to ventral portion of postoccipital suture; postgenal ridge partially or completely missing; no extra ridge anterior to postgenal ridge; postmandibular ridge short; infraorbital ridge incomplete; frontoclypeal, anterior frontal, parocular, posterior frontal, and basal punctures present; supra-antennal and interocular punctures absent. To avoid future confusion with the terminology of the setiferous punctures of the head in ventral view we decided to follow that of figure 1 of Smetana and Davies (2000) except for its 'genal seta' which we rename here as postmandibular setiferous puncture (PMP) in order to not confuse it with the 'genal puncture' of Brunke et al. (2019) which is located in the anterodorsal genal region. PMP is found in the anteroventral genal region, in the area delimited by the margin of the eye, the base of the mandible, and the maxilla, generally associated with the anterior part of the postmandibular ridge when present. In Loncovilius , the PMP is present, in the germaini group it is well developed ( Fig. 8E), and in the rest of the groups, it is reduced ( Fig. 8F). Gula with distinct transverse basal impression; gular sutures (gs) separated from each other. Antennal insertions situated at equal distance to frontoclypeus and to eye (except L. germaini with antennal insertions situated closer to frontoclypeus than to eye); antennae relatively long, all antennomeres elongate, antennomere 1 shorter than or subequal to antennomeres 2 and 3 combined, antennomeres 4 to 11 with tomentose pubescence, males with antennomere 11 (a11) distinctly longer than antennomere (a10) (a11:a10 ratio>1.5), this character varies in females. Mandibles in dorsal view slightly straight with curved base and apex; right mandible with proximal tooth and distal tooth with varying shape; teeth of left mandible vary. In germaini group, on right mandible, distal tooth bifid, space between proximal and distal teeth narrow and smooth. In edwardsianus , lividipennis , semiflavus , and variabilis groups, on right mandible, distal tooth not bifid, space between proximal and distal teeth wide and rough; in germaini group left mandible only with proximal, not bifid tooth; in edwardsianus , lividipennis , semiflavus , and variabilis groups left mandible with proximal and distal teeth not bifid, the latter short and truncated, space between teeth rough, in lateral view right and left mandibles deflexed ventrally at an angle of 25–30° c. one-fourth to one-third distance from base to apex; ligula small and entire; labrum with transparent apical membrane; maxillary palpomere 4 (mp4, apical) more or less subconical, with evenly narrowed apex, as long as or longer than palpomere 2; preapical maxillary palpomere 3 only weakly wider than apical palpomere, about as long as mp4; labial palpomere 2 with sparse brushes of setae.

Thorax: Chaetotaxy of pronotum varies between species groups. Paired punctures in dorsal series ( PPDS) may be present in different combinations; sublateral setiferous punctures ( SLSP) defined here as punctures found in the area between PPDS, anterior marginal row of setiferous punctures ( AMRSP), large lateral setiferous puncture ( LLSP) and large posterior setiferous puncture ( LPSP). Loncovilius carlsbergi sp. nov. has the most complete chaetotaxy set where all types of setiferous punctures occur ( Fig. 9A). Pronotum and prosternum not fused, pronotosternal suture complete even in procoxal cavity; postcoxal hypomeral translucent process present, rounded or triangular; sternacostal ridge not protruding, not joining with superior line of hypomeron; basisternum (bs) flat with few punctures, triangular, its lateral arms narrowed subapically, without pair of macrosetae, bs distinctly longer than furcasternum (fs) (bs/fs ratio>1.5). Elytra without humeral spines or spine-like setae; mesoscutellum setose without posterior scutellar ridge or subbasal ridge; hind wings with veins CuA and MP4 fused in one vein, vein MP3 absent; metascutellum with mid-longitudinal suture; apex of intercoxal process in mesothorax rounded or broadly pointed, forming obtuse angle; anterior margin of mesoventrite confluent with distinctly oblique sternopleural suture; posterior border of mesocoxal cavities complete; mesometasternal suture present. Tarsal formula 5-5-5; protibiae cylindrical to slightly broadened apically, ventrally with a middle long spine directed anteriad; protarsomeres 1–3 distinctly wider than long, bilobed, and ventrally with pale adhesive setae; ventral side of meso- and metatarsomeres 1–4 in males and females with pale adhesive setae; pale adhesive setae on meso- and metatarsi with terminal plate ( Fig. 8B) or without ( Fig. 8C); all legs with a pair of empodial setae distinctly shorter than claws; procoxae with internal and external ridges present, internal not running along external ridge, ending distinctly before or nearly joining external ridge; metacoxae with no more than four spines on posterior surface; mesotarsal segments with pale adhesive setae.

Abdomen: Protergal glands absent; tergites III–VI with anterior transverse basal carina (ATBC) laterally straight continuing to paratergites, tergite VII with ATBC not continuing to paratergite, tergites VII and VIII with ATBC descending laterally without reaching tergite margin ( Fig. 9D); all tergites without PTBC; anterior margin of tergites and sternites III–VI entire; tergite VII with white fringe along posterior edge; tergite IX in males at least slightly longer than tergite VIII; apical margin of male sternite VIII with medial emargination; basal portion of male sternite IX asymmetrical; paramere fused to median lobe only at base and very closely appressed to median lobe along entire length, often of complex and diverse shape, with minute pale sensory peg setae or usual peg setae; internal sac often with visible sclerites; ovipositor with two paired gonocoxites and minute styli.

Distribution and habitat: The genus is only known from Chile and Argentina; in Chile from the regions of Araucanía, Aysén, Los Lagos, Los Ríos, Magallanes and Chilean Antarctica, Maule, Ñuble, O’Higgins, and from Santiago Metropolitan; in Argentina from the provinces of Chubut, Neuquén and Río Negro ( Fig. 4). The genus occurs in the area from lowlands to 2600 m elevation in the mountains, with an average annual rainfall of between 500 and 3000 mm and an average annual temperature of between 1°C and 12°C. It is confined to various types of forests in the Chilean Matorral, Magellanic subpolar, and Valdivian temperate forest ecoregions. It has been collected using Malaise and flight intercept traps, sifting moss, dead wood, and leaf litter, beating and directly from flowers of the families Cunoniaceae , Ericaceae , Loranthaceae , Myrtaceae , and Winteraceae .

Remarks: The monophyly of Loncovilius is supported by two unique synapomorphies: females with pale adhesive setae present at mesotarsal segments 2–4 [(character 69, state 1; reversed condition in variabilis and edwardsianus groups (character 69, state 0)]; tergite IX at least slightly longer than tergite VIII (ratio up to 1.1, character 92, state 1); and by five homoplastic synapomorphies: eyes small [(eye/head length ratio more than three-tenths but less than half, character 37, state 1; in semiflavus group and L. impunctus eyes of medium size (eyes/head length ratio more than half but less than three-quarters, character 37, state 2)]; metascutellar mid-longitudinal suture well developed (character 82, state 0); protergal glands absent (character 84, state 0); female sternite VIII with medial emargination at apical margin [(character 99, state 1; reversed condition in variabilis and edwardsianus groups (character 100, state 0)]; paramere(s) with black sensory peg setae [(character 105, state 1; reversed condition in edwardsianus group (character 105, state 0)].