Stenocerus mesosternalius, Lopes & Mermudes, 2018

Lopes, Marcela Paes De A. M. & Mermudes, José Ricardo M., 2018, Four new species and new synonymy in Stenocerus Schoenherr, 1826 (Coleoptera, Anthribidae, Anthribinae, Stenocerini), Zootaxa 4472 (3), pp. 471-488 : 481-484

Stenocerus mesosternalius sp. nov.

( Figs. 43–56 )

Etymology: mesosternum + alius (= other or another from latin, pron.), allusive to the distinct mesosternal process from S. angulicollis , with which it is most structurally similar.

Diagnosis: Rostrum with dorsolateral carina only; lacking median longitudinal carina. Pronotum with antebasal carina bisinuate; lateral carina elongate and slightly curved, reaching apical third of prothorax, more prominent at proximal portion. Mesosternal process impressed at apex, anterior margin concave, lacking lateroapical expansion, sides sinuous and feebly convergent, and posterior margin subrounded. Tegmen with pre-apical margin subrounded, parameres short and fused, with sides parallel and apically convergent, apical margin weakly sinuous, with dense and moderately long setae (laterally sinuous).

Description: Male ( Figs. 45–56 ). Integument black-brownish. Dorsal vestiture: rostrum with short, fine and decumbent, black-brownish scales intermingled with light brownish and yellowish scales (variable in tone colour); frons near upper ocular margin, with narrow yellow stripe, formed by short, dense and decumbent scales; antennomeres III–XI ( Fig. 47 ) with fine, elongate, erect brown-yellowish setae throughout the antennomeres; club (IX–XI) with dense and short light brownish pubescence; pronotum and elytra with yellowish, light and blackbrownish scales; elytra ( Fig. 51 ) checkered pattern of alternating yellow and black-brownish spots on interstria 1; basal and apical third on interstriae 3, 5 and 7; pygidium ( Fig. 53 ) with black-brownish scales intermingled with yellowish. Ventral vestiture: abdomen black-brownish scales with minute pale yellow spots; tibiae with discrete yellow annular stripe at median third; tarsomere I yellowish, and II brownish and yellowish.

Head slightly microcorrugate. Rostrum ( Fig. 45 ) sharply microcorrugate, about 1.5x longer than basal width, punctate-corrugate at anterior angles; apical margin notched, angulate at middle; dorsolateral carina extending from base of rostrum to scrobes; sides, with distance between scrobe and eye ( Fig. 46 ) subequal to maximum width eye; ventral surface longitudinally elevated, grooved at sides, lacking fovea. Mentum glabrous, smooth surface, and apical margin subtruncate. Gula with fine and sparse punctures. Antennae ( Fig. 47 ) reaching posterior third of pronotum; scape stout; antennomere III elongate and depressed, about 1.3x as long as IV, widest at base, III–XI depressed dorsoventrally; III–VIII slightly decrease at length; IX–XI subequal in length; XI convergent at sides, and apex subacuminate.

Prothorax ( Figs. 48–49 ) about 1.5x wider than long. Pronotum ( Fig. 48 ) with moderate and broad depression, more sharply close to antebasal carina, with discrete central and transverse elevation; antebasal carina bisinuose; lateral carina ( Fig. 49 ) elongate and slightly curve, reaching apical third of prothorax, more prominent at proximal portion. Prosternum flattened at disc, corrugated; prosternal process not exceeding distal margin of procoxal cavity. Mesosternal process ( Fig. 50 ) slightly shorter than width mesocoxal cavity, depressed at apex, anterior margin concave, lacking latero-apical expansions; sides convergent and sinuous; posterior margin subrounded. Scutellum subrectangular with subrounded apex. Elytra ( Fig. 51 ) 1.3x longer than basal width across humeri, with discrete basal gibbosities; lacking tubercles.

Abdomen ( Fig. 52 ): ventrites I–IV slightly depressed at middle; ventrite V about 2.5x longer than IV, discreetly depressed at sides, and apical margin truncate. Pygidium ( Fig. 53 ) with length of apical portion 2.2x longer than proximal half; apical margin wide and evenly rounded. Terminalia ( Figs. 54–55 ): tergite VIII ( Fig. 54 ) with subparallel sides, weakly wider than long, apical margin feebly truncate, and sclerotized near side and apex, moderately elongate setae; sternite VIII membranous, with latero-apical lobes defined, very feebly sclerotized, and moderately elongate setae; sternite IX with apodemes one third longer than tergite, arms very short, about 1/8 of apodeme length. Tegmen ( Fig. 55 ) with apodeme subqual to sclerotized ring; this with basal margin pigmented, and rod 2x longer than arms; pre-apical margin sharply rounded; parameres short and fused, subparallel sides, apically convergent; apical margin slightly sinuous, with moderately long and dense setae; slightly sinuous in lateral view. Penis ( Fig. 56 ) elongate and curved; body as long as half apodemes; bridge between apodemes sclerotized at proximal margin; tectum elongate, barely pigmented, about 2x longer than wide, with sclerotized sides and convergent to apex; pedon continuous with apodemes, these sclerotized gradually from the base to the apex; sides convergent to subtruncate apex. Internal sac 1/3 shorter than length apodemes, with dorsal and proximal area spiculate.

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Type material: Holotype male from Brazil, Espírito Santo [Alegre], Fazenda Jerusalem , 18/XII/1914, Zikán, J. F leg., Coleção J. Z. Zikan (N° 11.453 I.O.C.; CEIOC 3919 ) —dissected; Stenocerus mesosternalius sp. nov. Holotype male, Lopes & Mermudes det. 2017 (CEIOC). Paratypes, same locality as holotype: 1 male 06/XII/1914, Coleção J. Z. Zikan (N° 11.455 I.O.C; CEIOC 3921 ) and 2 females with same locality and collector as holotype: one with same date, Coleção J. Z. Zikan (N° 11.454 I.O.C; CEIOC 3920 ) ; the second, 21/XII/ 1914, Coleção J. Z. Zikan (CEIOC 3915).

Remarks: Stenocerus mesosternalius sp. nov. is similar to S. angulicollis Jekel, 1855 (characters of S. angulicollis in parentheses) which differs by: 1) integument blackish-brown (red-brownish); 2) rostrum lacking median carina, but with median longitudinal groove and lateral carinae (rostrum with only single longitudinal carina); 3) mesosternal process depressed at apex, anterior margin concave, lacking latero-apical expansions; sides convergent and sinuous, subrounded at posterior margin (convergent sides without sinuosity, with posterior margin broadly rounded); 4) tegmen with pre-apical margin sharply rounded; parameres short and fused, subparallel sides, apically convergent; apical margin slightly sinuous, with moderately long and dense setae; slightly sinuous in lateral view (margin pre-apical with shape of “w”, parameres elongate and fused, sides parallel and apical margin subtruncate, in lateral view curve).

Figures

FIGURES 43–44. Stenocerus mesosternalius sp. nov., holotype male from Fazenda Jerusalem (Espírito Santo): 43, dorsal; 44, lateral.

FIGURES 45–56. Stenocerus mesosternalius sp. nov., holotype male: 45, head, dorsal view; 46, head, lateral view; 47, antennae; 48, pronotum; 49, prothorax, lateral; 50, mesosternal process; 51, elytra, dorsal; 52, abdomen, ventral; 53, pygidium, dorsal; 54, segment VIII (tergite and sternite) ventral; 55, tegmen dorsal and lateral; 56, penis dorsal and lateral.