Sphenarium histrio Gerstaecker, 1873

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 : 51-52

Sphenarium histrio Gerstaecker, 1873

(http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:37005)

Sphenarium carinatum Bolivar, 1904

Description. External morphology ( Figs. 15 Q, R, S, T; 18C, D; 20A, B, C, D, E, F, G, H, I, J): total body length ranging from 22.01 to 41.8 mm in females and from 18.57 to 38.87 mm in males. In most cases: antennae filiform, slightly shorter in females or longer than head and pronotum together in males; head subtriangular-elongated slightly longer than wide in females or conical notably longer than wide in males, 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 strap-like in both sexes; subgenital plate of males somewhat tapered in the apex; dorsal ovipositor valves rounded or lanceolate slightly elongated towards the apex. Male genitalia: bridge of ectophallus slightly longer than the length of lateral plates ( Figs. 19 G-I, J-I; 21A-I, D-I, G-I). Ectophallus in dorsal view small with lateral borders of ramus convergent, straight (morphotypes 1, 3, and 4; Figs. 19 G-II; 21A-II, D-II, respectively) or slightly rounded (morphotypes 2 and 5; Figs. 19 J-II; 21G-II, respectively); basal emargination of cingulum notably or slightly developed; interspace between the apodemal plates notably closed. Ectophallus in posterior view with a conspicuous sclerotized hollow in the sheath closed (morphotype 4; Fig. 21 E) or moderately open (other morphotypes; Figs. 19 H, K; 21B, H); inflections of supraramus moderately developed, with distal borders ventrally (morphotypes 1, 2, and 5; Figs. 19 H, K; 21H, respectively) or laterally directed (morphotypes 3 and 4; Fig. 19 B, E, respectively); valves of cingulum principally triangular but with distinct variations, each morphotype with its own form; Figs. 19 H, K; 21B, E, H), small (morphotypes 1-4) or moderately large (morphotype 5). Ectophallus in lateral view with valves of cingulum moderately developed dorsoposteriorly (morphotype 5; Fig. 21 I) or not developed posteriorly (morphotypes 1-4; Figs. 19 I, L; 21C, F, respectively). Endophallus in lateral view ( Figs. 19 G-III, J-III; 21A-III, D-III, G-III) with a short pseudoarch tightly joined to the valves of cingulum; aedeagal valves very small, tapered in the apex without apical spine; aedegala valves and sclerites as long as (morphotype 5, Fig. 21 G-III) or about ¾ (other morphotypes; Figs. 19 G-III, J-III; 21A-III, D-III) the length of dorsal inflections of endophallic apodemes.

Colouration. Ground colours vary from olive green, yellow or brown. Body uniformly coloured ( Fig. 15 R, T; 20B) or with the following colour traits ( Figs. 15 Q, S; 20A, B, C, D, E, F): antennae black, gray or dark blue; fastigium blue, brown or black; lateral postocular bands frequently present, narrow and yellowish; dorsal medial line frequently present, wide, yellowish or whitish; dorsal shades frequently present black, brown to dark blue, in southern populations covering entirely the dorsal portion of the body ( Fig. 20 C, D); lateral shades often present, black or dark blue; lateral bands of blotches frequently present, mostly reddish, in some populations in northern ranges of the species yellowish ( Fig. 15 S); ventral bands of pronotum often present, wide, whitish or bluish; pronotum with white lateral carinas and small strips and dots in the posterior margin; mesonotum dorsally red; frequently mesonotum and metanotum laterally white or yellow; lateral blotches of 1st abdominal segment frequently present and whitish; tegmina green, red, magenta or blue; generally hind femora uniformly coloured with knees laterally black, dorsally bluish or brownish; hind tibia green, brown, reddish or blue.

Diagnosis. Externally S. histrio is very similar to S. mexicanum , S. totonacum sp.n., and S. occidentalis sp.n. Nevertheless, the phallic structures of S. histrio differ from other species as follows: ectophallus small, conspicuous sclerotized hollow of the sheath moderately open or close, inflections of supraramus moderately developed with distal portions ventrally directed in most cases (except in morphotypes 3 & 4), and valves of cingulum with distinct form not developed or slightly developed dorsoposteriorly.

Distribution. This species is distributed in elevations ranging approximately from 15 to 2225 m a.s.l. in Chiapas, Guerrero, Oaxaca, Tabasco, Veracuz, in southern Mexico; and in the states of Huehuetenango and Santa Rosa in Guatemala ( Fig. 7 B). We observed that the five morphotypes identified within the species are apparently restricted to different geographic areas. The morphotype 1 is mainly distributed across the southern Pacific Cost and the outer slope of the Sierra Madre del Sur in Oaxaca. The morphotype 2 is distributed in the Pacific Cost south of the Isthmus of Tehuantepec, as well as in the mountain ranges of Chiapas and north-western Guatemala. The remaining morphotypes are more geographically restricted: the morphotype 3 is distributed principally in the central Valleys of Oaxaca in the Sierra Madre del Sur ( Fig. 7 B, C), the morphotype 4 was observed in the southeastern portion of the Sierra Madre del Sur also in Oaxaca ( Fig. 7 B, C), and morphotype 5 was observed only few localities in the Pacific Cost of Chiapas, Mexico ( Fig. 7 B). Overall, here we recognised smaller distribution ranges for S. histrio than in Boyle (1974) and Kevan (1977). Within the examined material we identified two S. histrio males from Sonora (morphotype 2) and Sinaloa (morphotype 3). However, we considered these specimens as mislabelled records considering that multiple collectors, including us, have not recorded S. histrio beyond the above-specified limits. Moreover, according to the revised material, S. histrio is apparently absent from the lowlands of the Isthmus of Tehuantepec where S. mexicanum is distributed. Additional fieldwork will clarify if these two species are sympatric in this geographic region.

Material examined. S. histrio : holotype m ( Fig. 18 C) from Mexico; designation by monotypy; location: BZM. S. carinatum : holotype m ( Fig. 18 D) from Guatemala: Santa Rosa, Testuaco; designation by monotypy; location: SIE. We could examine only the external morphology of this type material. Additional material: 398 m, 326 f, form 91 Mexican and Guatemalan localities (Appendix Table 5).

Taxonomic discussion. Gerstaecker (1873) originally described S. histrio based on a single male from an unknown Mexican locality considering mainly coloration traits as diagnostic characters for this species. Bolivar (1884) re-described this species based on a male and a female, but also from an unspecified Mexican locality. The validity of this species remained constant in posterior taxonomic studies. Hebard (1932) recognized a closer relationship between S. histrio and S.mexicanum based on their morphological resemblance. Later, Márquez (1962) and Boyle (1974) identified differences in endophallic morphology between these two species. However, Boyle (1974) and Kevan (1977) only recognized S. histrio as a subspecies of S. mexicanum ( S. mexicanum histrio ). Recently, Pedraza-Lara et al. (2015) and Sanabria-Urbán et al. (2015) have proposed the recognition of S. histrio as an independent and valid species within the genus based on morphologic and genetic evidence. In our phylogenetic analysis S. histrio was recovered as a paraphyletic species despite its notable morphologic cohesiveness. Moreover, we observed notable genetic (with CO1 P-distance> 3%) and morphological differentiation in the male genitalia between S. histrio and S. mexicanum . Therefore, here we also agreed in considering S. histrio as a valid species. Moreover, during this revision we examined several specimens collected near to the reported localities of two putative new taxa recently identified, Sphenarium sp. Oax9 and Sphenarium sp. Oax2 (Pedraza-lara et al. 2015) (L11, L167, L172, and L173; Appendix Table 5). The male genitalia of these specimens were similar to those of other S. histrio individuals. Moreover, CO1 sequences of these taxa intermingled with our samples of S. histrio ( Fig. 11 ). Therefore, we consider that these putative new taxa probably represent part of S. histrio .

Sphenarium carinatum was originally described based on a single male from an uncertain Guatemalan locality, Testuaco, probably Tecuaco ( Bolivar 1904). In later taxonomic studies this species was synonymised with S. m. histrio ( Boyle 1974; Kevan 1977). In this study we examined multiple specimens from north-western Guatemala; which were similar to other S. histrio individuals in southern Mexico. Therefore, in the lack of additional evidence we agree in recognising S. carinatum as a synonym of S. histrio .

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 11. Bayesian phylogeny of Sphenarium species based on CO 1 sequences of Pedraza-Lara et al. (2015) and this study. The analysis was conducted using the substitution model estimated previously and under the same conditions above specified for the concatenated phylogenetic analysis in methods section. Terminals of different colours represent the 17 recognized species in this study. Black dots behind the nodes indicate PP values greater than 95 %. Black bottom bars are equal to 0.04 substitutions per site.

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 18. Type specimens of S. bolivari: lectotype m (A) and paralectotype m (B); S. histrio holotype m (C) and S. carinatum holotype m (D) (Scale bars = 1 cm).

FIGURE 19. Male genital structures of S. mexicanum: morphotype 1 (A – C) and morphotype 2 (D – F); S. histrio: morphotype 1 (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 20. External morphology of S. histrio: morphotype 2 m (A and C) and f (B and D), morphotype 3 m (E) and f (F), morphotype 4 m (G) and f (H), and morphotype 5 m (I) and f (J); S. occidentalis sp. n. holotype m (K) and paratypes m # 2 (M), f # 3 (L) and f # 4 (N); S. totonacum sp. n. holotype m (O) and paratype f # 1 (P); S. adelinae sp. n. holotype m (Q) and paratype f # 1 (R); S. miztecum sp. n. holotype m (S) and paratype f # 1 (T) (Scale bars = 1 cm).

FIGURE 21. Male genital structures of S. histrio: morphotype 3 (A – C), morphotype 4 (D – F), and morphotype 5 (G – I); and S. occidentalis sp. n. holotype (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).