Acanthocollum Opitz, 2010

Opitz, Weston, 2010, Classification, Natural History, and Evolution of the Epiphloeinae (Coleoptera: Cleridae). Part VIII. The Genera Acanthocollum Opitz, Stegnoclava Opitz, and Ichnea Laporte, The Coleopterists Bulletin (mo 9) 64, pp. 1-65 : 8

Acanthocollum Opitz, 2010

Acanthocollum Opitz, 2010: 2 . Type species: Enoplium melanurum Klug, 1842: 376 . By original designation.

Diagnosis. The extensive setal tuft along the sides of the pronotum and the longitudinal carinae on the elytral disc are two apotypic characteristics that will distinguish the members of this genus from others in subfamily Epiphloeinae .

Description. Size: Length 11.3 mm; width 3.3 mm. Form: Oblong triangular; elytral outer margins gradually widened to posterior fourth. Integumental color: Antennae dark brown; cranium and pronotum bicolored; elytral disc with combinations of yellow and dark regions. Vestiture: Integument highly setose; cranium and pronotum often densely vested with decumbent setae; elytra very densely vested with short secondary setae (setae that are found between punctuations) and less profusely distributed primary setae (setae that are found adjacent to punctuations), the latter particularly prominent along epipleural margin and elytral distal fourth. Head ( Figs. 2–4 ): Cranial setose punctures large, frons and vertex subrugose, frons vertically indented; eyes very prominently bulging, finely faceted, and deeply, broadly incised along frontal margin; antenna ( Fig. 1 ) capitate, inserted at lower angle of eye incision, 10-segmented, scape short, robust, and triangular, with prominent dorsal carina and about as long as funicular antennomeres 3–7 combined, pedicel transverse, funicular antennomeres compressed together so that their combined length is about as long as length of antennomere 8, funicular antennomeres very expanded laterally, antennomere 5 narrow acuminate, antennomere 7 annulate, antennomeres 8–10 forming a large, loose capitulum that comprises about three-fourths length of antenna; labrum ( Fig. 7 ) deeply incised, transverse tormal processes horizontal and contiguous; mandible ( Fig. 6 ) subfalciform, dens well developed, mandibular penicillus well developed; maxilla ( Fig. 12 ) with palpomere 4 conical, laterolacinia present; labium ( Fig. 8 ) with palpomere 3 truncate; gula ( Fig. 4 ) triagonal; cranium notably indented near posterior margin of the eye. Thorax: Pronotum transverse, PL/PW 0.9, lateral tubercle subacute ( Fig. 5 ), disc densely sculptured with small coarse punctations; anterior transverse depression absent, posterior transverse depression prominent, pronotal collar very narrow; discal and lateral trichobothria prominent, bothria domed; pronotal projections ( Fig. 11 ) only slightly extended towards the middle, lateral carina confluent with hypomeral hem at pronotal posterior angle; procoxal cavities open; elytral epipleural margin gradually broadened to distal four-fifths, then gradually rounded to apex, about five times longer than pronotum, about three times longer than broad; elytral disc with three carinae, epipleuron not explanate, outer sides strongly deflexed behind humerus, elytral disc adjacent to epipleuron strongly indented, punctations small, much narrower than width of interstitial spaces, subseriate at basal half; mesoscutellum subglobose; protibial anterior margin with 16 spines; tibial spur formula 0-1-1; tarsal pulvillar formula 3-3-1; unguis with basal denticle; metathoracic wing as in Fig. 9 ; metendosternite without furcal lamina ( Fig. 10 ). Abdomen: Six visible sterna; pygidium entire, without triangular, depigmented notch, posterior margin evenly convex. Male genitalia: Aedeagus narrowly long. Female genitalia: Ovipositor of moderate length; dorsal lamina comprised of six lobes; ventral lamina with three lobes.

Distribution. This monotypic genus is known only from central and southeastern Brazil.

Figures

Figs. 1–8. Acanthocollum melanurum. 1) Antenna; 2) Head, frontal view; 3) Head, dorsal view; 4) Head, ventral view); 5) Forebody, dorsal view; 6) Mandible; 7) Labrum; 8) Labium.

Figs. 9–14. Body structures of Acanthocollum melanurum (9–12) and Stegnoclava spp. (13–14). 9) Metathoracic wing; 10) Metendosternite; 11) Pronotum, ventral view; 12) Maxilla; 13) Antenna of Stegnoclava zorropsis; 14) Antenna of Stegnoclava velatis.