Sphenarium variabile Kevan & Boyle, 1977

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 : 46-47

Sphenarium variabile Kevan & Boyle, 1977

(http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:37029)

Description. External morphology ( Figs. 14 H; 17A; 15I, J, K, L): total body length ranging from 21.38 to 25.57 mm in females and from 16.29 to 28.22 mm in males; antennae filiform, slightly shorter in females or notably longer than head and pronotum together in males; head subtriangular-compressed, wider than long with spherical eyes in females or subtriangular-elongated moderately longer than wide with oval eyes in males; fastigium notably reduced, less than half the length of interocular space in females or moderately elongated, nearly half the length of interocular space in males; tegmina spatula-like in both sexes; subgenital plate of males rounded, moderately developed posteriorly; dorsal ovipositor valves lanceolate, moderately elongated towards the apex. Male genitalia: bridge of epiphallus moderately longer or as long as the length of lateral plates ( Fig. 16 G-I, J-I). Ectophallus in dorsal view ( Fig. 16 G-II, J-II) with lateral borders of ramus convergent, slightly sinuous; basal emargination of cingulum notably developed reducing completely the interspace between the apodemal plates. Ectophallus in posterior view ( Fig. 16 H, K) with a conspicuous sclerotized hollow in the sheath moderately closed or open; inflections of supraramus moderately developed laterally (morphotype 1; Fig. 16 H, arrow) or anteriorly (morphotype 2; Fig. 16 K, arrow); valves of cingulum small whit distinct finger-like form, slender (morphotype 1; Fig. 16 H) or somewhat broad (morphotype 2; Fig. 16 K); notably developed posteriorly (morphotype 1; Fig. 16 I) or not (morphotype 2; Fig. 16 L) in lateral view of ectophallus. Endophallus in lateral view ( Fig. 16 G-III, J-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 or the same length as the dorsal inflections of endophallic apodemes.

Colouration. Ground colours vary from green to brown. Body uniformly coloured ( Fig. 15 J, L) or with the following colour traits ( Fig. 15 I, K): antennae black, brown or pale orange; fastigium often brownish; lateral postocular bands frequently present, narrow, yellowish or whitish; dorsomedial line often present, narrow and whitish; dorsal shades frequently present, black or brown, covering partially the dorsal part of the body, frequently well delimited in pronotum by the lateral carinas ( Fig. 15 I); lateral shades frequently present, black or dark brown, restricted to head and pronotum; lateral bands of blotches not evident; ventral bands of pronotum often present, wide and whitish; mesonotum partially or entirely black; lateral blotches of 1st abdominal segment whitish frequently present; hind femora with lower medial area sometimes whitish with knees laterally black, dorsally brownish; hind tibia black, green or orange.

Diagnosis. Externally this species is very similar to S. purpurascens . Sometimes, principally in sympatry, these species differ from each other in their colouration patterns. For instance, in S. variabile males the dark dorsal shades are more conspicuous and notably delimited by the lateral carinas of pronotum (e.g. Figs. 14 H; 15I) than in S. purpurascens males ( Fig. 9 A, C). Moreover, in S. variabile the dorsomedial line of body frequently lack the pinkish colourations that are commonly found in S. purpurascens . Nonetheless, S. variabile clearly differs from other species of Sphenarium by its unique lateral borders of ectophallus convergent, slightly sinuous and its fingerlike valves of cingulum.

Distribution. This species is restricted to inner valleys and highlands of the Sierra Madre del Sur in Oaxaca, Mexico, in elevations ranging from 838 to 2279 m a.s.l. ( Fig. 7 A, C). According to our results, the two morphotypes of this species are distributed separately northeast (morphotype 1) and southwest (morphotype 2) of the southern portion of the Sierra Madre del Sur.

Material examined. Holotype m ( Fig. 14 H) from Mexico: Oaxaca, 18 mi. NW. La Reforma (Km 695 onHwy. 190; 32mi WNW. Tequisistlan), 2750ft, IX-14-1959 (I. J. Cantrall & T. J. Cohn #116). Allotype f ( Fig. 17 A) same data as holotype . Paratypes from Mexico: Oaxaca: 1 f, same locality as holotype; 1 m, 45 mi. NW. Tequisistlan (1 mi. S. El Camaron), 2000ft, XII-21- 1958 (T.J. Cohn #384) ( Fig. 12 I; 13G, H, F) ; 1 m, 13mi. SE. Tlacolula, XII-21- 1958 (T.J. Cohn #383); 1 m, 1.0 mi. NW. Tamazulapan at Km 388, IX-9-1958 (T.J. Hubell, I.J. Cantrall & T.J. Cohn #87); 1 m, 2 f, 2 mi. SE. Tlacolula on Hwy. 190, 5700ft, IX-11-1961 (T. J. Hubell, I.J. Cantrall & T.J. Cohn #91) ; 1 m, 3 f, 7mi. SE. El Camaron (37mi. NW. Tequesistlan on Hwy. 190), 3500ft, IX-14-1959 (I.J. Cantrall & T.J. Cohn #117) ; 1 m, Mitla , 5000ft, VIII-11-1938 (H.R.Roberts). Designation: Kevan and Boyle (1974); location: UMMZ for all these type specimens. We examined both external and genital morphology of the type material. Additional material: 89 m, 38 f, from 15 new localities (Appendix Table 5).

Taxonomic discussion. This species was briefly described based on several specimens from seven different localities from Oaxaca, Mexico ( Kevan 1977). In this original description the holotype, allotype and 68 paratypes of were designated. Since its original description the validity of S. variabile has remained unchanged for later studies (Pedraza-lara et al. 2015; Sanabria-Urbán et al. 2015). According to our results, S. variabile is genetically close and paraphyletic with respect to S. purpurascens and S. zapotecum sp.n. lineages. However, the differentiation between their male genital structures is greater than that observed between other congeners with greater genetic differentiation. Therefore, we also agree in considering S. variabile a valid species.

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 9. External morphology of S. purpurascens: morphotype 1 m (A) and f (B), morphotype 2 m (C) and f (D), and morphotype 3 m (E) and f (F); S. zapotecum sp. n. holotype m (G) and paratype f # 23 (H); S. tarascum sp. n. holotype m (I) and paratype f # 2 (J,); S. planum m (K) and f (L); S. macrophallicum paratype m # 230 (M) and f (N); S. minimum m (O) and f (P); S. infernalis sp. n. holotype m (Q) and paratype f # 2 (R); S. rugosum morphotype 1 m (S) and f (T) (Scale bars = 1 cm).

FIGURE 12. Male genital structures of S. tarascum sp. n. holotype (A – C); S. planum (D – F); S. macrophallicum paratype # 234 (G – I); and S. minimum (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).

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).

FIGURE 17. Type specimens of S. variabile: allotype f (A); S. mexicanum lectotype f (B) and paralectotype m (C); O. crassipes holotype m (D); S. ictericum: lectotype m (E) and paralectotype f (F); S. marginatum lectotype m (G) and paralectotype f (H) (Scale bars = 1 cm).