Solenoptera tomentosa Lingafelter

Lingafelter, Steven W., 2015, The Prioninae (Coleoptera: Cerambycidae) of Hispaniola, with Diagnoses, Descriptions of New Species, Distribution Records, and a Key for Identification, The Coleopterists Bulletin 69 (3), pp. 353-388 : 373-375

27. Solenoptera tomentosa Lingafelter , new species ( Figs. 4i , 10d , 12a , 17b )

Discussion. Only two specimens of this species are known, both males and both from Jaragua National Park in the southwestern part of the Dominican Republic. This species is very similar to S. scutellata and S. fraudulenta but is distinguished by the moderately dense pubescence scattered over most of the elytra (elytra are glabrous in S. scutellata and S. fraudulenta ); the pronotum with small, dense patches of white pubescence along the elevated margins of the central depression at middle (pronotal disk is glabrous in S. scutellata and S. fraudulenta ); prosternal process weakly notched at apex with apices not divergent (similar to that in S. fraudulenta , but the prosternal process has a deep notch and greatly diverging apices in S. scutellata ); metasternum with dense coating of white pubescence over entire anterior and lateral portions, continuous with densely pubescent metepisternum (metasternal pubescence limited to narrow, oblique fascia in S. scutellata and S. fraudulenta ); and ventrites densely, broadly pubescent on margins [the paratype has ventrite 2 completely pubescent] (abdominal pubescence is limited to the extreme lateral margins in S. scutellata and S. fraudulenta ).

Description, Male (Holotype, Paratype). Size 31.0–34.0 mm long; 10.0–12.0 mm wide between elytral humeri; integument with head dark brown, pronotum dark reddish brown, elytra dark reddish brown at base, gradually becoming lighter reddish brown posteriorly; femora, tibiae, and basal antennomeres dark brown; tarsi and apical antennomeres reddish brown; venter dark brown. Head with pronounced, sparsely punctate sulcus on frons between upper eye lobes and antennal tubercles, narrowing on vertex. Antennae extending to just beyond midpoint of elytra; glabrous; moderately punctate. Antennomeres elongate, slightly broadened apically; not triangular. Antennomeres not flattened; antennomeres 8–10 abruptly constricted at base. Antennomeres 3–10 successively decreasing in length; 11 with subapical constriction and 1.5 times longer than 10. Poriferous sensory areas as follows: very small dorsal apicolateral patches on antennomeres 3–7; very small apicodorsal, apicomesal, basidorsal, and basimesal patches on 8–9; small patches on most of dorsal surfaces of 10–11.

Pronotum 10.0–12.0 mm wide; 6.2–7.5 mm long (1.6 times wider than long); with shiny, mostly impunctate central sulcus widened anteriorly near margin; non-shiny, densely micropunctate lateral to sulcus to crenulate margins, divided by narrow, oblique, shiny, sparsely punctate ridge; with small patch of dense, white pubescence on either side of posterior half of median sulcus, otherwise with only few scattered setae on margins and dense fringe of golden pubescence on anterior margin. Pronotum without defined spines on margin, but with acute posterolateral angle, behind which pronotum is narrowed abruptly. Prosternal process weakly notched at apex with apices not divergent and apex only slightly wider than region between procoxae. Base of prosternal process lacking ventral protuberance.

Elytra 20.0–23.0 mm long; 5.0–6.0 mm wide (3.8 times longer than wide); with moderately dense, fine, suberect setae over entire surface; slightly tapering apically; not divergent apically at suture. Semirugose basally, densely punctate throughout; punctures becoming smaller and denser apically. Elytral apex very weakly dentiform apicolaterally and at suture, rounded between denticles with only a few, indistinct crenulae. Scutellum rounded or subreniform, very slightly acute posteriorly; completely covered in very dense, white pubescence. Legs short, hind femur extending to apical fifth of elytra. Femora gradually clavate, finely punctured, with sparse pubescent patches on lateral face; without denticles. Tibiae densely golden orange pubescent on inner margins on apical half (pubescence most dense and long on protibiae). Metasternum with dense coating of white pubescence over all of anterior and lateral portions, continuous with densely pubescent metepisternum. Mesosternum densely pubescent except at middle. Abdomen with venter densely, broadly pubescent along margins (ventrite 2 completely pubescent in paratype) but glabrous at middle and extreme lateral border. Last ventrite equal in length to fourth, with deep, broad emargination at middle.

Etymology. The epithet tomentosa is a Latin nominative singular feminine adjective meaning furry and refers to the very dense pubescence on the pronotum, scutellum, thoracic sternites, and abdominal ventrites.

Type Data. Holotype (male): DOMINICAN REPUBLIC: Pedernales Province (3 km south of Los Tres Charcos , 17°48.063′N, 71°26.809′W, 99 meters, 16 July 2006, Nearns and Lingafelter [ ENPC donated to USNM]) . Paratype (male): DOMINICAN REPUBLIC: Pedernales Province (Parque Nacional Jaragua, Oviedo, Carlitos , 13 October 1998, R. D. Perez [ WIBF]) .

Derancistrachroma Lingafelter , new genus ( Figs. 7a–c , 8a–f , 9a–e )

Discussion. In their revision of Solenopterini, Galileo and Martins (1993a) distinguish the tribe from the other Neotropical diurnal prionines on the basis of: lateral margins of the pronotum horizonal, not directed ventrally, and most often crenulate on the posterior half; metanotum not exposed between pronotum and elytral base; mesosternum projecting, without notable sulcus; integument lacking metallic luster; scutellum relatively small, semicircular, cuneiform, or triangular; antennae lacking pronounced sexual dimorphism and not flabellate or serrate in one sex but not the other. They further characterize members of the tribe by having: a medial, longitudinal sulcus welldemarcated on the head; widely separated antennal tubercles; finely faceted eyes; elongate, often acute genae; relatively short, 11-segmented antenna extending to around midpoint of elytra; antennal poriferous system progressively more developed on apical antennomeres; and prosternal process well-developed and extending beyond the posterior plane of the procoxae.

The key of Galileo and Martins (1993a) is not adequate to assess affinity for this new taxon since several character states cannot be clearly interpreted. The cuneiform scutellum which is also as long as wide is not mutually exclusive for the new species of Derancistrachroma , thus couplet 1 cannot be used. The prosternal process is very slightly notched, but it is unclear how to interpret the state for couplet 3. The prothorax has a series of small spines or large denticles on the margins, terminating with a large, recurved posterolateral spine. Since the anterolateral spine or denticle is not clearly distinct from the adjacent one, it is unclear how to interpret this character state for couplets 4 and 5. Therefore, on the basis of the key, it is difficult to say to which genus Derancistrachroma has the closest affinity. Different interpretations could lead one to the conclusion that it is closest to Prosternodes Thomson, 1861 , Derancistrus , or Solenoptera . This new genus shares with Prosternodes the deeply sulcate head and strongly acute genae. With Derancistrus , Derancistrachroma shares the deep frontal impression on the head and similar pronotal margins with pronounced posterolateral spine. It shares with some species of Solenoptera , particularly S. dominicensis , a similar laterally dentate pronotum with a semispiniform anterolateral margin (absent in most Solenoptera , however) and recurved posterolateral spine with a basal pronotal constriction. It also shares with Solenoptera the medially sulcate head and pronounced gena, but in Solenoptera these features are far less developed.

The characters for Derancistrachroma are listed in the generic diagnosis below and included in more detail with all other character states in the type species description. The peculiar integument with very low albedo is unique to this genus within the tribe. No other Cerambycidae are known with this type of non-reflective, sparsely puncticulate surface. Crowson (1981) discusses in great detail the cuticular properties, appearance, color, and luminosity of Coleoptera and indicates the rarity of completely black species in Chrysomeloidea. In their review of iridescence and structural color mechanisms in Coleoptera, Seago et al. (2009) , likewise, did not mention this type of integument which apparently completely lacks multilayer reflectors or diffraction gratings (e.g., strigulose microsculpture or microtrichiae), the primary means of light reflectance. Likewise, this type of surface sculpturing and coloration is not mentioned for any species treated in Svacha and Lawrence (2014). This character along with the features of the pronotum, head, and ventral sclerites justify establishing this taxon as a new genus.

Diagnosis. Integument of elytra, pronotum, head, antennae, and legs puncticulate, with matte, nonreflective surface. Pronotum with two raised, pockmarked protuberances on disk. Pronotal pubescence comprised of numerous apically converging tufts of setae. Pronotal margins rounded anterolaterally, with 5–6 small lateral spines and large, recurved posteromedial spine. Prosternal base with pronounced, acute ventral tubercle. Prosternal process very thick, weakly bilobed at apex, articulating dorsally into space between procoxae and mesosternum, rugulose at procoxae. Genae acutely projecting anteroventrally beyond mandibular base. Ventrite 5 of female (male unknown) truncate at apex.

Etymology. The genus name is a composite of the Latin Derancistrus meaning hooked neck, referring to the pronounced posterolateral pronotal spine, and the Greek achroma meaning without color, referring to the completely black integument that reflects virtually no light. It is feminine in gender.

Type species. This genus is monotypic with the only known species, Derancistrachroma melanoleuca Lingafelter , new species, here designated as the type species.

Figures

Fig. 4. Dorsal habitus of Hispaniolan Solenoptera species. a) S. furfurosa, male, b) S. furfurosa, female holotype, c) S. scutellata, male, d) S. scutellata, female, e) S. vittata, male, f) S. vittata, female, g) S. helbi, female holotype, h) S. rugosa, female holotype, i) S. tomentosa, male paratype.

Fig. 10. Hispaniolan Prioninae. a) Elateropsis dichroma, female holotype, ventral view, b) Elateropsis woodleyi, male holotype, ventral view, c) Solenoptera scutellata, male, ventral view, d) Solenoptera tomentosa, male paratype, ventral view, e) Hovorodon bituberculatum, female, prosternal process, f) H. bituberculatum, female mandible, lateral view, g) Stenodontes exsertus, female mandible, lateral view.

Fig. 12. Living Hispaniolan Prioninae. a) Solenoptera tomentosa, male holotype (photograph by Rick Stanley),

Fig. 17. Distribution maps of Hispaniolan Prioninae. a) Solenoptera vittata and Solenoptera furfurosa, b) Solenoptera helbi, Solenoptera tomentosa, and Derancistrachroma melanoleuca.

Fig. 7. Derancistrachroma melanoleuca, female holotype. a) Dorsal habitus, b) Ventral habitus, c) Lateral habitus.

Fig. 8. Derancistrachroma melanoleuca, female holotype. a) Pronotum and head, dorsal view, b) Prosternum, mesosternum, and head, ventral view, c) Head, anterior view, d) Head, lateral view, e) Lateral pronotal margin, f) Prothorax and prosternum, lateral view.

Fig. 9. Derancistrachroma melanoleuca, female holotype. a) Scutellum, b) Elytral apex, c) Elytral integument,