Adocimus (Belanotus) nitidulus ( Grouvelle, 1897 ) Kirejtshuk, Alexander G. & Kovalev, Alexey V., 2022

Kirejtshuk, Alexander G. & Kovalev, Alexey V., 2022, Monograph on the Cillaeinae (Coleoptera: Nitidulidae) from the Australian Region with comments on the taxonomy of the subfamily, Zootaxa 5103 (1), pp. 1-133 : 24-27

8. Adocimus (Belanotus) nitidulus ( Grouvelle, 1897) , comb. nov.

Figs 3 , A–H

Brachypeplus nitidulus Grouvelle, 1897: 344 , Perak;

? = Cillaeus Modiglianii Grouvelle, 1897: 347 ; Sumatra.

Specimens examined. Type specimens: lectotype of Brachypeplus nitidulus here designated (NHML), male— “65846”, “Lewis, 1910—247”, “Doherty”, “Perak Mh.” (Malaysia), “Fry Coll. 1905-100”, “ Brachypeplus nitidulus Grouv. ”; Lectotype of Cillaeus modiglianii , female, here designated (MCNG), female—“ SUMATRA, SI-RAMBÉ, XII.90–III.91, E. Modigliani” (Sirambas), “ Cillaeus Modiglianii ty. Grouv.” (handwritten by A. Grouvelle); Additional specimen: Indonesia: 1 female (SMNS)—“W-Sumatra, Bukit-tinggi, Gn. Merapi, 18.10.1990, 1900– 2100 m, A. Riedel.”

Diagnosis. This species by its slender body is similar to Adocimus (Belonotus) bartenevi sp. nov. and differs from it in the darker body coloration, longer and elongate subparallel-sided antennal club (not regularly oval) and different proportions of other antennomeres, narrower femora, shorter tibiae, apex of female pygidium rounded and with another serration.

Notes on probable synonymy. The lectotypes of both Brachypeplus nitidulus and Cillaeus modiglianii are different mostly in the characters which could be variable and sexual. They are the length of exposed part of labrum, length of head and outline of temples, shape of pronotum, length of abdominal segments. At the same time, two females from Sumatra show a considerable similarity in all mentioned characters which give a reason to doubt in conspecific relation of them with the examined male (lectotypes of Brachypeplus nitidulus ). Thus, to solve this problem is necessary to study additional specimens.

Description of lectotype of Brachypeplus nitidulus (male). Length of body with abdomen 4.2, length of body without abdomen 2.8, width 1.1, height 0.3 mm. Elongate, slightly convex to subflattened dorsally and ventrally; subunicolorous dark castaneous with somewhat lighter antennae and tarsi; body shining; dorsum almost without pubescence, although posterior edge of pronotum with dense microsetae, dorsal abdominal sclerites glabrous, except for short and thin yellowish setae along sides, and very short and slightly conspicuous hairs on pygidium becoming more conspicuous distally and long hairs along its posterior edge; underside also scarcely pubescent, but apex of prosternal process with dense thin and long hairs, hypopygidium with almost inconspicuous short and sparse hairs becoming more conspicuous distally.

Head and pronotum with punctures, mostly coarser than eye facets, separated by 2–4 puncture diameters, interspaces between them smooth; elytra with clear and slightly oblique striae coordinated with distinct punctures in bottom of these striae (punctures about 2.0 × coarser than those on head and pronotum); exposed abdominal dorsal sclerites with punctures slightly smaller than those on head and pronotum, and smoothly alutaceous. Prosternum with much finer punctures than those on head and pronotum, separated by 4–7 puncture diameters, and interspaces between punctures smooth. Metaventrite with slightly finer and slightly sparser punctures than those on head and pronotum, interspaces between punctures smooth. Abdominal ventrites with somewhat finer and denser punctation than that on thoracic underside and becoming denser on hypopygydium; interspaces between punctures smooth along middle of ventrites 1–4 and alutaceous or finely microreticulate at their sides; hypopygidium with rather pronounced mesh microreticulation.

Head widest at eyes and slightly arcuately narrowing posteriorly. Anterior edge of frons subtruncate. Labrum with widely rounded anterior edge, about 2.5 × as wide as long. Mandibles with one small subapical tooth, subtransverse anterior edge and sharply angular at side. Antennae about three fourths as long as head width, scape moderately swollen and more than 2.0 × as long as each of antennomeres 2 and 3 (antennomere 3 slightly longer than antennomere 2), antennomere 2 markedly thicker than antennomere 3, oblong club about two sevenths of total antennal length, almost 2.0 × as long as wide and with antennomere 9 narrower and longer than antennomere 10 comparable in width and length, antennomere 11 shorter and narrower than previous two antennomeres. Pronotum slightly shorter than wide, somewhat narrowed both anteriorly and posteriorly with regularly arcuate lateral edges, anterior edge nearly bi-emarginate and posterior edge nearly gently convex. Scutellar shield subtriangular, about 2.5 × as wide as long. Elytra subparallel-sided, slightly longer than their combined width, rather steeply sloping at sides. Abdomen as wide as pronotum with segment 4, almost completely covered by elytra dorsally and with laterosternites V and VI not widened posteriorly, subparallel-sided in distal three fourths; tergite VI somewhat longer than tergite V; postbasal lines of exposed tergites behind elytral apices sharply expressed reaching posterior two thirds of length of tergites. Pygidium nearly as long as wide, subtruncate and scarcely serrate at apex.

Pregenal processes comparatively narrow and at wide hypostomal sinuses subarcuately curved. Terminal maxillary palpomere more than 2.0 × and terminal labial palpomeres about 2.0 × as long as thick and subcylindrical. Mentum rather widened anteriorly and with strongly projecting anterior angles, nearly 4.0 × as wide as long. Arcuate antennal grooves convergent and expressed only between eyes and pregenal processes. Median plate of prosternum arcuately widened anteriorly from prosternal process. Prosternal process strongly widened before subtruncate apex, with subflattened median plate of prosternal process arcuately widening behind procoxae. Distance between procoxae almost as great as length of antennal club, and somewhat smaller than that between mesocoxae and somewhat greater than that between metacoxae. Metaventrite subflattened and with clear discrimen in distal two thirds. Metepisterna gradually narrowing posteriorly and at base much wider than mesotarsomere 1. Abdominal ventrite 1 longer than ventrite 2; ventrite 3 about as long as ventrites 1 and 2 together and somewhat shorter than ventrite 4. Hypopygidium slightly transverse, about as long as ventrite 4 and shallowly emarginate at apex.

Pro- and mesofemora of usual shape and nearly 2.5 × as wide as corresponding tibiae; metafemur more than 3.5 × as wide as metatibia. Protibia somewhat narrower than antennal club, comparatively coarsely serrate along outer edge, with two spines along lower edge of apex and one very strong spur curved inwards. Meso- and metatibiae about as wide as protibia, with one row of short and stout spines along outer edge becoming stronger distally, one or two largest spines at outer apical angle and this row continuing by three greater spines along lower edge of apex approaching to moderately thin and moderately long spur. Tarsi with widest and longest tarsomere 1 (slightly wider than antennomere 2), following tarsomeres thinner, claws simple and narrow.

Male anal sclerite subtruncate at apex with four strong teeth and two small teeth at outer angle of anal sclerite. Aedeagus moderately sclerotized. Tegmen almost 2.0 × as long as wide and with subangular apex bearing two paramedian brushes of thin and short hairs. Penis trunk slightly shorter than tegmen with widely rounded to subangular apex.

Female. Lectotype of Cillaeus modiglianii and additional specimen. Lectotype length of body with abdomen 5.1 and length without abdomen 2.8 mm; body coloration brownish with somewhat lighter disk of elytra, bases of abdominal segments, antennal flagella, tibiae and tarsi; pronotum with arcuate sides. The additional female from Bukittinggi with the length of body with abdomen 7.1 and length without abdomen 3.7 mm; straw reddish with darker (brownish) head, antennal clubs and lower thoracic sclerites; body somewhat slenderer than that in the lectotype; pronotum of the latter somewhat more elongate. Ovipositor moderately sclerotized, outer lobes of gonocoxites about 2.0 × as long as inner lobes; sharply acuminate at apex and with styli located at distance from apex 3.0 × greater than length of one stylus.

Distribution. This species is known only from the type localities of Adocimus (Belonotus) nitidulus comb. nov. in Malayan Peninsula (Perak) and A. (B.) modiglianii comb.nov. in Sumatra (Sirambas), and also the latter from Sumatra (Bukittinggi).

Figures

FIGURE 3. Adocimus (Belonotus) nitidululus comb. nov., orig.A, E–G: lectotype of Brachypterus nitidulus, male from Malay Peninsula (“Perak…”); B, C, D, H: lectotype of Cillaeus modiglianii, female from Sumatra (“… Si-Rambé…” = Sirambas); A: body dorsal; B: body of dorsal; C: head, dorsal; D: head and thorax, ventral; E: male anal sclerite, ventral; F: tegmen, ventral; G: penis trunk, dorsal; H: ovipositor, ventral. Scale bars: a = 1.0 mm to Figs A and B; b = 1.0 mm to Figs C and D; с = 0.3 mm to Fig. E and 0.25 mm to Figs F–H.