Sphenarium borrei Bolivar, 1884

Sanabria-Urbán, Salomón, Song, Hojun, Oyama, Ken, González-Rodríguez, Antonio & Castillo, Raúl Cueva Del, 2017, Integrative taxonomy reveals cryptic diversity in neotropical grasshoppers: taxonomy, phylogenetics, and evolution of the genus Sphenarium Charpentier, 1842 (Orthoptera: Pyrgomorphidae), Zootaxa 4274 (1), pp. 1-86 : 45-46

Sphenarium borrei Bolivar, 1884

(http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:37036)

Sphenarium bruneri Bolivar, 1909

Description. External morphology ( Figs 14 D, E, F, G; 15G, H): total body length ranging from 26.82 to 31.76 mm in females and from 21.08 to 30.62 mm in males; antennae filiform, notably shorter in females or slightly longer in males than head and pronotum together; head conical notably longer than wide and with oval eyes in both sexes; fastigium moderately elongated, nearly half the length of interocular space in females or notably elongated, nearly as long as the interocular space in males; tegmina spatula-like in both sexes; subgenital plate of males rounded moderately developed posteriorly; dorsal ovipositor valves lanceolate, notably elongated towards the apex. Male genitalia: bridge of epiphallus as long as the length of lateral plates ( Fig. 16 D-I). Ectophallus in dorsal view ( Fig. 16 D-II) broad at the base, with lateral borders of ramus convergent; basal emargination of cingulum notably developed towards the base reducing completely the interspace between the apodemal plates. Ectophallus in posterior view ( Fig. 16 E) with a conspicuous sclerotized hollow in the sheath notably closed; inflections of supraramus notably developed anterolaterally; valves of cingulum triangular, stout and notably developed posteriorly ( Fig. 16 F). Endophallus in lateral view ( Fig. 16 D-III) with a short pseudoarch tightly joined to the valves of cingulum; aedeagal valves very small, tapered in the apex without apical spine; aedeagal valves and sclerites about ¾ the length of dorsal inflections of endophallic apodemes.

Colouration. Ground colours vary from green, yellow or brown. Body uniformly coloured or with the following colour traits ( Fig. 15 G, H): antennae frequently black or brown; fastigium often reddish to pinkish; lateral postocular bands frequently present, narrow, yellowish, whitish or pinkish; dorsomedial line absent; dorsal shades sometimes absent, if present almost entirely restricted to the head, metanotum and abdomen apex, brown or black; lateral shades often present, black or dark brown, principally restricted to head and pronotum; lateral bands of blotches absent; ventral bands of pronotum often present, narrow and pinkish; frequently posterior margin of pronotum pinkish; mesonotum is partially or entirely black; tegmina green, black or magenta; lateral blotches of 1st abdominal segment absent; fore and middle femora pinkish; sometimes hind femora with upper and lower medial areas black and whitish, respectively; knees of hind femora laterally black, dorsally reddish; hind tibia frequently black.

Diagnosis. Externally this species sometimes resembles S. purpurascens and S. infernalis sp.n. However, S. borrei differs from these species principally by its notably elongated head (conical in both sexes) and dorsal ovipositor valves, as well as its pinkish colourations in the ventral and posterior margins of pronotum when present. At the level of male genitalia, S. borrei more closely resembles other species with a conspicuous sclerotized hollow in the sheath (all species described below). Nevertheless, S. borrei differs from other species in the genus by the following combination of male genitalia characters: lateral borders of ramus convergent, basal emargination of cingulum notably developed, sclerotized hollow of the sheath conspicuous and closed, inflections of supraramus notably developed anterolaterally, valves of cingulum triangular and stout, posteriorly developed, and aedeagal valves very small.

Distribution. This species is distributed in elevations ranging from 304 to 2225 m a.s.l. and is principally restricted to the western portion of the Mexican Volcanic Belt in Colima, Guanajuato, Jalisco, Michoacan, Nayarit and Zacatecas, Mexico ( Fig. 7 A).

Material examined. S. borrei : lectotype m ( Fig. 14 D) and paralectotype f ( Fig. 14 E), from Mexico: Guanajuato (E. Duges); designation: Kevan (1960, unpublished results); location: Royal Institute of Natural Sciences of Belgium (RISCNB), Brusseles, Belgium . S. bruneri : lectotype m ( Fig. 14 F) and paralectotype f ( Fig. 14 G), from Mexico (Coneradt); designation: Kevan (1960, unpublished results); location: Spanish Institute of Entomology (SIE), Madrid, Spain. We could only examine the external morphology of all these type specimens. Additional material: 214 m, 178 f from 65 localities (Appendix Table 5).

Taxonomic discussion. Bolivar (1884) originally described this species from one male and female syntypes from Guanajuato, Mexico. He recognized this species based on the morphology of head, antenna and ovipositor valves, as well as coloration patterns. For posterior taxonomic studies this species remain valid until Márquez (1962) synonymised it as S. purpurascens despite he did not examined specimens of this species. Later , Boyle (1974) re-established the status of this species and this status remain stable for posterior molecular analysis ( Pedraza-lara et al. 2015; Sanabria-Urbán et al. 2015). According to our results, S. borrei is the most differentiated species in the genus in both morphological and genetic characters. Moreover, its well-supported monophyly and geographic restrictiveness support his recognition as a valid species.

Sphenarium bruneri was only briefly described based on unstated number of specimens ( Bolivar 1909), probably one male and two females from an unspecified Mexican locality. Originally, Bolivar (1909) stated a close relationship between this species and S. rugosum . However, he mainly considered highly variable external traits in differentiating S. brunerri from its congeners. The validity of S. bruneri is questionable and its taxonomic position has remained uncertain. This species has been considered as a synonym of S. histrio ( Boyle 1974) or S. purpurascens ( Kevan 1977) . Nevertheless, considering the close resemblance in the morphology of head, tegmina and ovipositor valves between S. borrei and S. bruneri , it is probable that S. bruneri represents a junior synonym of S. borrei .

Figures

FIGURE 7. Geographic distribution of Sphenarium species. Numbers within parenthesis in front of taxa names indicate the number of identified morphotype within the species. White surrounded areas and upper case abbreviations denote the Mexican biogeographic provinces. AC, Altos de Chiapas; AL, Altiplano Sur; BRB, Balsas River Basin; GMC, Gulf of Mexico Coast; MVB, Mexican Volcanic Belt; PC, Pacific Coast; SMOC, Sierra Madre Occidental; SMOR, Sierra Madre Oriental; SMS, Sierra Madre Sur; SO, Soconusco; and SOX, Sierra de Oaxaca.

FIGURE 14. Type specimens of S. rugosum: lectotype m (A) and paralectotype f (B); S. barrettii: lectotype m (C); S. borrei: lectotype m (D) and paralectotype f (E); S. bruneri lectotype m (F) and paralectotype f (G); S. variabile: holotype m (H) (Scale bars = 1 cm).

FIGURE 15. External morphology of S. rugosum: morphotype 2 m (A) and f (B), morphotype 3 m (C) and f (D); S. crypticum sp. n. holotype m (E) and paratype f # 45 (F); S. borrei m (G) and f (H); S. variabile: morphotype 1 paratype m # 134 (I) and f (J), and morphotype 2 m (K) and f (L); S. mexicanum: morphotype 1 m (M) and f (N), and morphotype 2 m (O) and f (P); S. histrio: morphotype 1 m (Q and S) and f (R and T) (Scale bars = 1 cm).

FIGURE 16. Male genital structures of S. crypticum sp. n. holotype (A – C); S. borrei (D – F); S. variabile: morphotype 1 paratype # 234 (G – I) and morphotype 2 (J – l). For all taxa left squares show epiphallus (I) and ectophallus (II) in dorsal view, and endophallus in lateral view (III); meddle squares show ectophallus in posterior view; and right squares show a close up of ectophallus in lateral view (Scale bars = 1 mm).