Stegnoclava 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 : 9-14

Stegnoclava Opitz, 2010

Stegnoclava Opitz, 2010: 25 . Ichnea fumigata Gorham, 1877: 414 . By original designation.

Diagnosis. There are two autapotypic characteristics that distinguish the members of Stegnoclava . First, the funicular antennomeres are drastically compressed together so that their combined length is shorter than antennomere 8 ( Figs. 13–15 ). Second, the cranium is marked by a black “mask” that traverses the frons and projects posteriorly to cover the vertex ( Fig. 16 ).

Description. Size: Length 6.1–9.1 mm; width 1.8–3.1 mm. Form ( Fig. 120 ): Slightly triangular; outer margins of elytra subparallel. Integumental color: Antennae dark brown; cranium bicolored, yellow with black band that traverses frons and extends posteriorly through vertex; pronotum bicolored, with broad medial vertical line and two paralateral yellow lines, lower sides black; elytral disc with combinations of yellow and dark regions, sometimes mostly yellow, sometimes mostly black; legs bicolored, with basal half of femora yellow and rest of leg black or dark brown; pterothorax and abdomen dark brown. Vestiture: Integument highly setose; cranium and pronotum often densely vested with decumbent setae; elytra densely vested with short secondary setae and less profusely distributed primary setae, latter particularly prominent along epipleura and elytral distal fourth. Head ( Figs. 16, 17 ): Cranial setose punctures large, frons and vertex subrugose, frons vertically indented; antennal carina prominent ( Fig. 15 ); eyes prominently bulging, finely faceted and deeply, broadly incised along frontal margin; antennae ( Fig. 15 ) inserted at lower angle of eye incision, capitate, 10-segmented, scape very short, robust, and triangular, with dorsal carina and about as long as length of funicular antennomeres 3–7 combined, pedicel transverse, funicular antennomeres compressed together so that their combined length is shorter than length of antennomere 8, funicular antennomeres expanded laterally, antennomere 5 narrowly acuminate, antennomere 7 small and slightly expanded, antennomeres 8–10 forming a large, loose capitulum that comprises about threefourths length of antenna; labrum ( Fig. 25 ) deeply incised, transverse tormal processes horizontal and contiguous; mandible ( Fig. 23 ) subfalciform, dens well developed, mandibular penicillus well developed; maxilla ( Fig. 22 ) with palpomere 4 elongate, laterolacinia present; labium ( Fig. 24 ), palpomere 3 elongate; gula ( Fig. 17 ) triagonal; cranium notably indented near posterior margin of eye. Thorax: Pronotum transverse, PL/PW 0.8–0.9, lateral tubercle obtuse ( Fig. 19 ), disc setose, punctures small; anterior transverse depression absent, posterior transverse depression prominent, pronotal collar narrow, discal and lateral trichobothria prominent, bothria domed, pronotal projection ( Fig. 18 ) only slightly extended towards the middle, lateral carina confluent with pronotal hem at pronotal posterior angle ( Fig. 20 ); epipleural margins subparallel, then gradually rounded to apex, about four times longer than pronotum, about 2.5 times longer than broad, epipleuron not explanate, outer sides strongly deflexed behind humerus, punctures small, much narrower than width of interstitial spaces, subseriate in basal half; mesoscutellum ( Fig. 21 ) subglobose; protibial anterior margin with 11–14 spines; tibial spur formula 0-1-1; tarsal pulvillar formula 3-3-1; unquis with basal denticle; metathoracic wing as in Fig. 32 ; metendosternite without furcal lamina ( Fig. 26 ). Abdomen: Six visible sterna; pygidium entire, without triangular depigmented notch, posterior margin evenly convex. Male genitalia: Aedeagus narrow, long ( Figs. 27–29 ), phallobasic lobes reduced, phallobasic rod long, phallobasic and phallic apodemes slightly expanded distally, spicular fork apodeme completely divided, interspicular plate slender and bifid distally. Female genitalia: Ovipositor of moderate length; dorsal lamina comprised of six lobes; ventral lamina with three lobes. Male mesodermal internal reproductive organs ( Fig. 33 ): Two pairs of accessory glands present.

Distribution. The members of this genus range from northeastern Costa Rica to south-central Brazil.

Figures

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.

Figs. 15–21. Stegnoclava fumigata. 15) Antenna; 16) Head, frontal view; 17) Head, ventral view; 18) Pronotum, ventral view; 19) Forebody, dorsal view; 20) Pronotum, lateral view; 21) Mesoscutellum.

Fig. 120. Habitus of Stegnoclava fumigata.

Figs. 22–31. Stegnoclava spp. 22) Maxilla of S. fumigata; 23) Mandible of S. fumigata; 24) Labium of S. fumigata; 25) Labrum of S. fumigata; 26) Metendosternite of S. fumigata; 27) Aedeagus of S. fumigata; 28) Aedeagus of S. zorropsis; 29) Aedeagus of S. velatis; 30) Forebody of S. zorropsis; 31) Forebody of S. velatis.

Figs. 32–35. Stegnoclava spp. 32) Metathoracic wing of S. fumigata; 33) Mesodermal male reproductive organs of S. velatis; 34) Mesodermal male reproductive organs of S. fumigata; 35) Mesodermal male reproductive organs of S. zorropsis.