Platytomus pittinoi Minkina & Byk, 2023

Minkina, Łukasz, Byk, Adam, Nowak, Cezary, Bidas, Marek & Mokrzycki, Tomasz, 2023, Platytomus pittinoi Minkina & Byk, a new species of Psammodiini (Coleoptera: Scarabaeidae: Aphodiinae) from Greece, Zootaxa 5319 (2), pp. 275-282 : 276-280

Platytomus pittinoi Minkina & Byk , new species

( Figs 1–3 , 7, 9–11, 15 )

Type locality. Greece, Florina region , Amindeo commune, W of Sotiras, 40°40′22′′N, 21°39′36′′E .

Type material. Holotype (♁): “ Greece | Florina reg., Amindeo co., W of Sotiras | 40°40′22′′N, 21°39′36′′E | 11.iv.2022 | leg. Ł. Minkina ” ( ŁMCN) . Paratypes (76 specimens): 5 specimens: same data as for holotype ( ŁMCN) ; 40 specimens: same data as for holotype but: “leg. C. Nowak ” ( CNCW) ; 2 specimens: same data as for holotype, but: “leg. A. Byk ” ( ABCW) ; 3 specimens: same data as for holotype, but: “ 09.iv.2022 ” ( ŁMCN) ; 7 specimens: same data as for holotype, but: “ 09.iv.2022, leg. M. Bidas ”( MBCK) ; 8 specimens: same data as for holotype, but: “ 09. iv.2022, leg. C. Nowak ” ( CNCW) ; 4 specimens: same data as for holotype, but: “ 08.iv.2022 ” ( ŁMCN) ; 2 specimens: same data as for holotype, but: “ 08.iv.2022, leg. M. Bidas ” ( MBCK) ; 5 specimens: same data as for holotype, but: “ 08.iv.2022, leg. C. Nowak ” ( CNCW) .

Description of the holotype (male). Dorsum ( Fig. 1 ). Body length: 3.1 mm. Small, brownish-black, elongate, shiny, glabrous.

Head ( Fig. 7 ) convex, moderately shiny, moderately microreticulate, trapezoidal; clypeus anteriorly very distinctly sinuate, distinctly rounded on sides of anterior sinuation, laterally widely rounded, not separated from genae. Genae quite distinctly protruding beyond eyes, distinctly rounded, widely emarginated, with few very short macrosetae sticking out from the basal margin. Clypeus surface granulate, granules very distinctly transverse; additionally sparsely and finely punctate, surface surrounding punctures elevated.

Epipharynx ( Fig. 15 ) distinctly transverse, anterior margin almost straight, laterally distinctly rounded; epitorma subquadrate, helus with irregularly spaced sensilla, anterior sensilla longer, directed to anterior margin; chaetopariae and chaetopediae very large and distinct; corypha and zygum absent; phobae glabrous; tormae relatively long, wide basally, rapidly tapering till apex.

Pronotum shiny, without microreticulation, transverse, widest somewhat behind midlength. Anterior angles weakly but distinctly excavate, widely rounded; sides arcuate, in basal half not visible from above, posterior angles broadly rounded. Borders not macrosetaceous. Anterior margin not, sides distinctly, base very distinctly and deeply bordered with confluent coarse punctures. Pronotum doubly punctate: smaller punctures fine, densely, quite regularly distributed, larger punctures very coarse, with diameter 8–15 times larger than small ones, moderately dense, irregularly distributed, in basal half weakly concentrated along midline to form loose stripe.

Scutellum small, triangular, with ogival sides; mat due to moderate microreticulation basally, on apical part rather lustrous, without microreticulation.

Elytra dark brownish, elongate, widest behind midlength, with ten striae and ten intervals. Humeral denticles absent. All intervals distinctly convex, shiny, without microreticulation, with quite dense, irregularly spaced, very fine punctures; striae shiny, deep, quite wide, with coarse, moderately dense punctures weakly indenting margins of intervals.

Protibiae with three distinct teeth on external margin in apical half, proximal part not serrulate. Apical spur elongate, very gently downwardly bent, longer than basal tarsomere. Superior apical spur of metatibiae distinctly longer than first metatarsomere, the latter as long as next two combined.

Pygidium ( Fig. 10 ) basally mat, with distinct microreticulation, deeply grooved along midline, covered by dense, thin, moderately long macrosetae; apically lustrous, without microreticulation, with dense, fine punctation and four thick, long macrosetae embedded in coarse punctures, median macrosetae somewhat longer; with one very large, ocellate, deeply indented, distinctly microreticulate, eroded surface above the long macrosetae.

Ventral surfaces ( Fig. 2 ). All femora brownish, sparsely and finely punctuate. Profemora distinctly bordered on apical, meso- and metafemora on basal margin. Meso-metaventral plate weakly convex at sides, weakly depressed along midline, shiny, without microreticulation, with distinct, longitudinal furrow in the middle, sparsely, very finely punctured. Abdominal ventrites shiny, with weak microreticulation, transverse row of slightly confluent punctures on basal margin, and very fine, sparse punctures near borders.

Aedeagus ( Fig. 11 ) thick. Parameres somewhat shorter than phallobase, distinctly bent downward before acute apex.

Variability. Body size: 2.9–3.6 mm. Body colour varies from brownish to brownish-black. Punctation of pronotum weakly variable. The number of macrosetae on the pygidium variable: there may be two or four; also specimens with three macrosetae and no puncture from which the lacking fourth macroseta could emerge have been observed. The shape of the deep, eroded depressed areas on the pygidium is highly variable, ranging from two eggshaped, distinctly microreticulate, eroded surface on sides ( Fig. 9 ) to one very large, ocellate ( Fig. 10 ).

Sexual dimorphism. Meso-metaventral plate of females somewhat more convex.

Etymology. The new species is dedicated to the Italian entomologist Riccardo Pittino, who was the first to mention the undescribed Platytomus species associated with rodents.

Differential diagnosis. Specimens of new species with four long macrosetae on pygidium are unique and easily distinguishable from all Palaearctic Platytomus species; those with two pygidial macrosetae are, among all Palaearctic species with convex, elongate shape of body, similar only with P. laevistriatus . From P. laevistriatus newly described species can be distinguished by features summarised in the Table 1 .

By the way, somewhat similar in body proportions and macrosetation of genae among Palaearctic species is also P. yadai, 2006 known from Japan, Qatar ( Bordat 2007) and United Arab Emirates ( Král & Batelka 2017) – but this species has ten long macrosetae on pygidium, what has not been noticed by previous researchers until now.

Figures

FIGURES 1–3. Platytomus pittinoi Minkina & Byk, new species, holotype, male. 1, dorsal view; 2, ventral view; 3, lateral view.

FIGURES 7–16. Details of morphology.7, Platytomus pittinoi Minkina & Byk, new species, male, holotype, head; 8, Platytomus laevistriatus (Perris, 1870), male, head; 9, Platytomus pittinoi Minkina & Byk, new species, female, paratype, pygidium, dorsal view; 10, Platytomus pittinoi Minkina & Byk, new species, male, holotype, pygidium, dorsal view; 11, Platytomus pittinoi Minkina & Byk, new species, holotype, aedeagus, lateral view; 12, Platytomus laevistriatus (Perris, 1870), female, pygidium, dorsal view; 13, Platytomus laevistriatus (Perris, 1870), male, pygidium, dorsal view; 14, Platytomus laevistriatus (Perris, 1870), aedeagus, lateral view; 15, Platytomus pittinoi Minkina & Byk, new species, male, holotype, epipharynx; 16, Platytomus laevistriatus (Perris, 1870), male, epipharynx.