Agrilinus matusiaki Minkina, 2022

Minkina, Łukasz, 2022, Studies on subfamily Aphodiinae (Coleoptera: Scarabaeoidea: Scarabaeidae) with description of three new species from the genera Agrilinus Mulsant & Rey, 1869 Gilletianus Balthasar, 1933 and Trichiorhyssemus Clouët, 1901, Zootaxa 5162 (3), pp. 223-242 : 224-229

Agrilinus matusiaki Minkina , new species

( Figs 1–3 , 15 , 30–32 )

Type locality. China, Tibetan Autonomous Region , Jiang Da County Bai-Ge .

Type material. Holotype (♂): “ China / Tibet, Jiang Da County / Bai-Ge / 01- 10.08.2006 / local coll.”.

Description of the holotype, male. Dorsum ( Fig. 1 ). Body length 6.9 mm, elongate, weakly shiny, orangebrownish with somewhat lighter elytra and extremities, glabrous.

Head ( Fig. 15 ) nearly semicircular, convex, weakly shiny, with weak microreticulation. Clypeus gently bordered, anteriorly and laterally widely rounded, not notched before genae, clypeal border without macrosetae. Genae obtuse, distinctly exceeding eyes, with few short setae. Frontoclypeal suture realtively weakly discernible, with four gibbosities: lateral ones weak, median distinct, very near each other; central epistomal gibbosity low. Clypeus distinctly, simply punctate: punctures weakly variable in size, densely, somewhat irregularly distributed, in basal part coarser, denser, more regularly distributed.

Epipharynx ( Fig. 32 ) transverse, with sides broadly rounded, anterior margin of pedia concavely arcuate, corypha clearly protruding from zygum, with few celtes, all celtes relatively the same length. Acanthopariae with dense, short and thick chaetae; acropariae with dense, long and thiner chaetae than on acanthopariae; chaetopariae with dense belt of very thin, very long chaetae; adelochaetae absent; prophobae with very dense, short and thin setae; chaetopediae with relatively sparse, thick and long chaetae. Tormae relatively thin, moderately long.

Pronotum transverse, approximately as wide as base of elytra, widest in the basal part, convex, moderately shiny, without microreticulation, with double punctation: larger punctures irregularly spaced, moderately large, regular in size, two to four times larger than the smaller ones, quite dense on sides, sparse on disc, and in anterior part; smaller punctures irregularly spaced, regular in size, rather dense; sides and base bordered, anteriorly not bordered; sides with relatively short, sparse setae; anterior and hind angles widely rounded, base of pronotum before hind angles truncate; hind angles rectangular.

Scutellum small, triangular, with sides widely ogival, with dense, moderately coarse, somewhat rugulose punctures, weakly shiny, with weak microreticulation.

Elytra elongate, convex, very slightly widened posteriorly, widest near the middle, moderately shiny, with weak microreticulation; without humeral denticles; with ten striae and ten intervals. Striae distinctly, densely and rather finely punctate; punctures extremely weakly indenting margins of intervals. First and tenth, seventh and eighth striae joined together before apex; all the rest shortened before apex, sixth to eighth striae slightly shortened before base, ninth and tenth striae joined before base. Intervals moderately shiny, distinctly convex, punctate, punctures fine, quite dense, irregularly spaced.

Legs. Femora shiny, with trace of microreticulation, finely and sparsely punctate. Protibiae distinctly tridentate laterally, proximally with few small teeth; its dorsal side shiny, with few very fine punctures; apical spur long, moderately broad, very weakly downwardly and outwardly directed, with acute apex. Meso- and metatibiae with two strong transverse carinae, fimbriate apically with row of relatively short spinules of equal length (viewed from the ventral side, however viewed from above spinules are not so short and there may be simple longer spinules). Metatibiae with the superior apical spur distinctly shorter than basimetatarsomere, the latter as long as than next three following metatarsomeres combined. Claws rather short, thick, distinctly arcuate.

Macropterous.

Pygidium with similar structure to ventrites.

Venter ( Fig. 2 ). Meso-metaventral plate shiny, flat, without longitudinal line at middle (however there is visible a longitudinal dark stripe); surface with fine, relatively sparse punctures. Abdominal ventrites rather matte, densely, not coarsely punctate; with distinct microreticulation; all punctures bearing rather long and thin macrosetae.

Aedeagus ( Figs 30–31 ) small and short. Parameres somewhat shorter than phallobase, narrowed in the middle, weakly downwardly directed, rounded apically when visible from above and from side.

Etymology. The new species is dedicated to my friend Andrzej Matusiak.

Differential diagnosis. Scutellum small, triangular, anterior margin of pronotum not bordered, basal margin of pronotum distinctly bordered, meso- and metatibiae with transverse carinae, fimbriate apically with row of short spinules of equal length, elytra glabrous, frontal suture with distinct tubercles, clypeal margin glabrous, aedeagus without membranous process – thanks them characters when we use key to genera by Dellacasa et al. (2001) there are no problems in assigning the newly described species to genus Agrilinus . Problem is that a lot of species of the genus Carinaulus agree with that characters too. Anyway, Agrilinus matusiaki Minkina , new species (as well a lot of species from genus Agrilinus ), can be distingished from all members of genus Carinaulus by combination of characters: elytral intervals glabrous, regularly convex, with weak microreticulation. All of Carinaulus have at least macrosetae in apical half of first interval; most of them have whole surface of elytral intervals with macrosetae. A lot of species of genus Carinaulus have distinctly elevated middle part of intervals, with sides more or less flattened (and here flattened part usually distinctly microreticulate). Others, without elevated middle part, have whole surface of intervals distinctly microreticulate.

I think it will be good to recall here that in the Dellacasa et al. (2016), Agrilinus inexspectatus (Balthasar, 1935) is treated as Carinaulus . However (in my opinion more correctly) it was treated as subgenus Agrilinus in genus Aphodius by Akhmetova & Frolov (2014). A separate issue, requiring more research is phylogenetic arrangement of both these genera.

Among whole genus Agrilinus there are not many species similar to A. matusiaki Minkina , new species. Because of its relatively large size of body (more than 6.0 mm), uniformly, brownish colored body and lack of denticles on the border of the clypeus this species may be confused only with Agrilinus striatus (Schmidt, 1910) ( Figs 7–9 , 17 ) and A. inexspectatus ( Figs 4–6 , 16 ). Additionally at first glance because of similar colour and size of body, not so distinctly deplanate sides of elytral intervals, which are moderately shiny, with weak microreticulation it may be confused with Carinaulus meghalayensis (Červenka, 2000) ( Figs 10–12 , 18 ). For separation all mentioned species refer Table 1 .

Additionally from all currently known species of genus Agrilinus or Carinaulus , the new species can, at first glance, be easily distinguished by frontoclypeal suture with four gibbosities ( Fig. 15 ).

Photographed material. See material for comparison.

Figures

FIGURES 1–3. Agrilinus matusiaki Minkina, new species. 1, habitus, holotype, dorsal view; 2, habitus, holotype, ventral view; 3, habitus, holotype, lateral view.

FIGURES 13–20. Heads and pronotum. 13, Trichiorhyssemus immaturus Minkina, new species, holotype, female, head; 14, T. immaturus Minkina, new species, holotype, female, pronotum; 15, Agrilinus matusiaki Minkina, new species, holotype, male, head; 16, Agrilinus inexspectatus (Balthasar, 1935), male, head; 17, Agrilinus striatus (Schmidt, 1910), male, head; 18, Carinaulus meghalayensis (Červenka, 2000), male, head; 19, Gilletianus miurai Minkina, new species, holotype, male, head; 20, Gilletianus sundainsulanus Ochi, Kon & Kawahara, 2014, male, head.

FIGURES 30–35. Details of the morphology. 30–32, Agrilinus matusiaki Minkina, new species, holotype, male: 30, aedeagus, lateral view; 31, aedeagus, dorsal view; 32, epipharynx.33, Gilletianus miurai Minkina, new species, holotype,male, epipharynx; 34, Trichiorhyssemus immaturus Minkina, new species, holotype, female, epipharynx; 35, T. immaturus Minkina, new species, holotype, female, druseform macrosetae on border of pronotum.

FIGURES 7–9. Agrilinus striatus (Schmidt, 1910). 7, habitus, male, dorsal view; 8, habitus, male, ventral view; 9, habitus, male, lateral view.

FIGURES 4–6. Agrilinus inexspectatus (Balthasar, 1935). 4, habitus, male, dorsal view; 5, habitus, male, ventral view; 6, habitus, male, lateral view.

FIGURES 10–12. Carinaulus meghalayensis (Červenka, 2000). 10, habitus, male dorsal view; 11, habitus, male, ventral view; 12, habitus, male, lateral view.