Prionus (Prionus) hectori, Tirant & Santos-Silva, 2023

Prionus (Prionus) Geoffroy, 1762

Prionus (Prionus) hectori sp. nov.

( Fig. 16-21)

ZooBank:http://zoobank.org/ 1150F769-2698-4E99-BDED-E849E6B0D78A

Holotype, ♀, MEXICO, Durango: Pueblo Nuevo, 2000 m, VII.2022, Hector Arellano ( MZSP).

Description

Coloration. – Integument mostly dark brown; elytra gradually, slightly lighter towardapex;posterior regionof gulamentum brown; ventral mouthparts light brown except yellowish apex of palpomeres; anteclypeus and labrum mostly dark yellowish brown. Femora and tibiae dark reddish brown, darker depending on light intensity, except dark-brown apex of femora and base of tibiae. Tarsi reddish brown with irregular blackish areas, except protarsomeres I mostly blackish.

Head. – Frons short, depressed, abundantly, coarsely punctate, except area under antennal tubercles abundantly, finely punctate; with

FAUNITAXYS - ISSN (Print): 2269 - 6016 - ISSN (Online): 2970 - 4960

16. Dorsal habitus. 17. Ventral habitus. 18. Lateral habitus. 19. Head, frontal view. 20. Antennomeres VIII-XV, lateral view. 21. Metatarsus, dorsal habitus a few minute, yellowish-brown setae. Area between antennal tubercles and anterior margin of upper eye lobes deeply, moderately widely, longitudinally sulcate centrally; abundantly, coarsely punctate laterally, moderately abundantly, finely punctate within longitudinal sulcus; glabrous toward frons and on longitudinal sulcus; most punctures with erect, short or long yellowish-brown setae on area close to eyes. Area between upper eye lobes slightly tumid; with narrow, shallow longitudinal sulcus centrally; abundantly, coarsely, partially confluently punctate laterally, punctures gradually finer and sparser toward center; sides with a few short, erect yellowish-brown setae; remaining surface glabrous. Area between posterior margin of upper eye lobes and prothorax with narrow, very shallow longitudinal sulcus centrally, not reaching prothorax; abundantly finely punctate, punctures sparser toward central region; with minute yellowish-brown setae posteriorly, glabrous on remaining surface. Area behind eyes densely, coarsely, confluently punctate close to upper eye lobe and superior region of lower eye lobe, except narrow, smooth area close to eye; abundantly, finely punctate close to vertex, densely, coarsely, partially confluently punctate on remaining area behind upper eye lobes and superior half of lower eye lobes, punctures finer than those close to eye; remaining surface behind lower eye lobes moderately coarsely rugose-punctate; with moderately abundant yellowish-brown setae not obscuring integument, setae slightly longer and more abundant close to lower eye lobe. Genae abundantly, minutely punctate close to frontal region of eye, sparsely, finely punctate on remaining frontal surface, punctures denser toward ventral surface; some fine punctures with minute yellowish-brown seta. Posterior half of gulamentum glabrous, smooth close to prothorax and sides of remaining surface, somewhat rugose-punctate on remaining surface; anterior half with sparse, moderately short, erect yellowish-brown setae, almost absent centrally, and abundantly, coarsely, confluently punctate, except striate-punctate area close to intermaxillary process. Antennal tubercles moderately sparsely, coarsely punctate basally, punctures gradually sparser and finer toward smooth apical region; glabrous. Wide central area of postclypeus abundantly, coarsely punctate, except shallower and partially confluently punctate, depressed central area close to anteclypeus; with sparse, erect yellowish-brown setae laterally, a few minute yellowish-brown setae centrally, except glabrous depressed central region. Sides of postclypeus, smooth, glabrous. Labrum coplanar with anteclypeus at posterior 2/3, inclined at anterior third; with a few short, erect yellowish-brown setae on posterior 2/3, and dense yellowish-brown setae directed forward on anterior third, setae paler centrally. Distance between upper eye lobes 0.3 times distance between outer margins of eyes; in ventral view, distance between lower eye lobes 0.25 times distance between outer margins of eyes. Antennae 15-segmented; 0.7 times elytral length, slightly surpassing anterior third of elytra. Scape sparsely, finely punctate, with coarser punctures interspersed; glabrous. Pedicel abundantly, finely punctate basally, sparsely, finely punctate on remaining surface, except smooth dorsal apex, with coarser punctures interspersed, especially ventrally; with short, erect yellowish-brown setae on base of dorsal surface and a few short, erect yellowish-brown setae on base of ventral surface. Antennomere III cylindrical, flattened ventrally; apical margin of ventral surface widely concave; outer apical angle rounded and inner apical angle slightly projected; glabrous, sparsely, finely punctate dorsally and laterally, except smooth apex of dorsal surface; densely, moderately coarsely punctate ventrally; glabrous. Antennomeres IV-VIII gradually widened from base to apex; ventral surface flattened; apical margin of ventral surface of IV widely concave; apical margin of ventral surface of V- VIII distinctly projected backward on outer surface; outer apex of dorsal surface of IV-VIII notched, less distinctly on IV; inner apex of dorsal surface of IV-VIII distinctly, subacutely projected; dorsal and lateral surface of IV-VIII sparsely, finely punctate with coarser punctures interspersed, coarser punctures more abundant toward VIII; ventral surface of IV-VIII moderately abundantly and coarsely punctate on inner surface, densely, coarsely punctate on outer surface, punctures on outer surface gradually denser and anastomosed toward VIII; IV-VIII glabrous. Antennomeres IX-X gradually widened from base to apex; apical margin of ventral surface distinctly imbricate, with apex of imbrication emarginate centrally; imbrication with longitudinal carina centrally from base to apex; surface of ventral imbrication partially striolate; dorsal surface sparsely, moderately coarsely punctate; lateral surfaces abundantly, coarsely punctate, punctures denser and partially confluent on X; outer apex notched; inner subrounded projected on IX; glabrous. Antennomeres XI-XIV gradually widened from base to apex; ventral surface, inner and outer apices of dorsal surface as on X, except XIV with slightly distinct imbrication; dorsal and lateral surfaces almost entirely striolate; glabrous. Antennomere XV ( Fig. 20) gradually narrowed toward acute apex; entirely striolate, without imbrication ventrally; glabrous.

Antennal formula (ratio) based on length of antennomere III (antennomeres measured on center of dorsal surface):

– Scape= 1.00 – Pedicel =0.34– IV= 0.61– V =0.57– VI =0.49– VII = 0.47 – VIII = 0.41– IX = 0.37 – X = 0.35– XI = 0.33– XII = 0.32– XIII = 0.25 –XIV = 0.22 – XV = 0.24.

Thorax. – Prothorax distinctly wider than long; anterolateral angles subtriangularly projected sideward; lateral tubercles long, spiniform located centrally; posterior region with small spine located close to rounded posterolateral angle. Pronotum with anterior margin slightly emarginate centrally; posterior margin sinuous, widely rounded centrally; with shallow, transverse sulcus on each side close to anterior margin; with shallow, transverse sulcus close to posterior margin; moderately abundantly, finely punctate, except coarser punctures laterally on anterior half, rugose-punctate laterally on posterior half, densely, finely punctate within posterior sulcus, and smooth posterocentral region; with sparse, moderately long, suberect yellowish-brown setae close to anterolateral angles and sides of posterior half, and a few short, erect yellowish-white setae on each side of posterior third of disc. Hypomera mostly smooth and glabrous. Prosternum abundantly, finely punctate, punctures finer and denser centrally; some puncture with minute yellowish-brown seta. Prosternal process distinctly more elevated than prosternum; basal region abundantly, finely punctate; remaining surface sparsely, finely punctate; glabrous, except moderately abundant yellowish-brown setae directed backward on rounded apex. Mesoventrite smooth, glabrous centrally; remaining surface abundantly, finely punctate, with abundant yellowish-brown pubescence not obscuring integument. Mesanepisterna and mesepimera with sculpturing and pubescence as on sides of mesoventrite, except area close to coxa on mesepimera with sparser punctures and pubescence. Mesoventral process with sides convergent toward apex; apex strongly notched centrally; with abundant yellowish-brown pubescence not obscuring integument. Metanepisterna with abundant yellowish-brown pubescence not obscuring integument. Metaventrite abundantly, finely punctate laterally, punctures finer and slightly sparser on remaining surface; sides with abundant yellowish-brown pubescence not obscuring integument, and remaining surface with a few minute yellowish-white setae. Scutellum large; sides slightly convergent toward apex; apex subtruncate,slightly emarginate centrally;sparsely, finely punctate;with a few short yellowish-white setae.

Elytra. – Sides distinctly widened from anterior sixth; abundantly, finely punctate, punctures denser from anterior quarter; apex rounded (sutural angle with short triangular projection on right elytron); dorsal surface shallowly, longitudinally sulcate from anterior quarter to posterior sixth; entirely glabrous.

Legs. – Femora sparsely, finely punctate; with a few short, erect yellowish-brown setae on outer surface, more abundant on profemora, sparse, erect yellowish-brown setae on inferior margin of inner surface of meso- and metafemora, and sparse, erect yellowish-brown setae on dorsal surface of profemora. Protibiae widened from base to apex; outer apex projected sideward; sparsely, finely punctate dorsally and laterally, except coarser punctures centrally close to inner margin of dorsal surface; with sparse, minute yellowish-brown setae dorsally and laterally; ventral surface with sparse, erect, thick dark yellowish-brown setae. Meso- and metatibiae abundantly, finely punctate; apical region or mesotibiae widened, with spiniform projection on apex of dorsal surface; apex of dorsal surface of metatibiae triangularly projected; dorsal surface of meso- and metatibiae glabrous, sides with sparse yellowish-brown setae, more abundant on mesotibiae, and ventral surface with moderately abundant dark yellowish-brown setae. Dorsal surface of tarsomeres with sparse, decumbent yellowish-brown setae, absent on center of tarsomeres I-III ( Fig. 21); metatarsomere I as long as II-III together.

FAUNITAXYS - ISSN (Print): 2269 - 6016 - ISSN (Online): 2970 - 4960

22- 24. Prionus (Prionus) aztecus Casey, 1912 , ♀ from Mexico (Durango). 22. Dorsal habitus. 23. Ventral habitus. 24. Metatarsus, dorsal habitus. 25-27. Prionus (Prionus) mexicanus Bates, 1884 , ♀ from Mexico (Durango). 25. Dorsal habitus. 26. Ventral habitus. 27. Metatarsus , dorsal habitus.

Abdomen. –Ventrites abundantly, minutely punctate, except smooth central apex of ventrites 1 -4, and fine puncture on posterior half of ventrite 5; ventrites 1 -4 mostly glabrous, with sparse yellowish-brown setae on abdominal process and sides of ventrite 1, a few minute yellowish-white setae on 2 -3, a few minute yellowish-white setae on anterior 2/3 of ventrite 4 and a few short yellowish-brown setae close to smooth area of ventrite 4; ventrite 5 with sparse, short yellowish-brown setae basally and laterally and sparse, a few minute yellowish-white setae on remaining surface; apex of ventrite 5 subtruncate.

Dimensions (mm)

– Total length, 46.50;

– Prothoracic length, 5.05;

– Anterior prothoracic width, 11.10;

– Posterior prothoracic width, 10.30;

– Maximum prothoracic width, 12.90;

– Humeral width, 15.05;

– Elytral length, 32.25.

Etymology. – This species is dedicated to our friend Hector Arellano who sent us the specimen for study.

Remarks. – By the spongy setal pads of the metatarsomeres distinctly longitudinally sulcate, the new species belongs to Prionus (Prionus) ( Santos-Silva et al. 2016; Schiefer 2022). Schiefer (2022) revalidated Prionus (Antennalia) Casey, 1912 and Prionus (Neopolyarthron) Semenov, 1899 . In females of P. ( Neopolyarthron ), the antennae have 15-23 antennomeres ( Schiefer 2022), and in females of P. (Antennalia) they have at least 20 antennomeres; in both subgenera,the metaventrite is glabrous in females. Although the number of antennomeres may allow including the new species in P. ( Neopolyarthron ), the laterally pubescent metaventrite excludes this option; the number of antennal segments and the pubescence on the metaventrite also exclude P. (Antennalia).The key to species of Prionus (Prionus) by Santos-Silva et al. (2016) leads Prionus (Prionus) hectori sp. nov. to the alternative of couplet “9,” with P. (P.) aztecus Casey, 1912 .

Females of Prionus (Prionus) hectori sp. nov. differ from those of P. (P.) aztecus ( Fig. 22-24) as follows: in ventral view ( Fig. 17), distance between lower eye lobes slightly larger than maximum diameter of scape; metanepisterna and sides of metaventrite with very short pubescence and remaining surface of metaventrite almost glabrous ( Fig. 17); apex of the scutellum slightly narrower than basal region; elytra distinctly expanded from anterior sixth; and dorsal surface of tarsi, especially metatarsi, subglabrous ( Fig. 21). In females of P. (P.) aztecus , the distance between the eye lobes in ventral view ( Fig. 23) is greater than twice the maximum diameter of the scape, the metanepisterna and sides of the metaventrite have moderately long pubescence, reaching the anterocentral region, the remaining surface has sparser but distinct pubescence ( Fig. 23), the apex of the scutellum is much narrower than base, the sides of the elytra are subparallel from the base to about posterior quarter, and the dorsal surface of the tarsi, especially metatarsi, has somewhat sparse but distinct pubescence ( Fig. 24).

Females of P. (P.) hectori sp. nov. is also similar to females of P. (P.) mexicanus Bates, 1884 ( Fig. 25-27), but differ by the same differences as from P. (P.) aztecus and by antennomeres IV-IV proportionally shorter (longer in P. (P.) mexicanus ).