Acridurus baracoae, Yong, 2017

Yong, Sheyla, 2017, First record of the genus Acridurus Perez, Dominici, Hierro and Otte, 1995 from Cuba, with description of a new species (Orthoptera: Acrididae: Ommatolampidinae), Ecologica Montenegrina 11, pp. 49-58 : 50-57

Acridurus baracoae new species

Figures 1–5 . Table I

"New species (possibly new genus) of Ommatolampidinae ": Yong & Perez-Gelabert, 2014: 408; fig. 1b.

"Genus unknown 2": Yong & Perez-Gelabert, 2014: 412.

Types. Cuba: Holguín Province: Moa Municipality: Ojito de Agua (20°29'07"N - 74°59'25"W, 350 m a.s.l.); on the vegetation; February–March/1993; A. R. Estrada; one adult female holotype ( SY, in ethanol 80%). Same locality; 23/June/1987; A. Torres; one adult female paratype ( SY, dry pinned) . Guantánamo Province: Yateras Municipality: Piedra La Vela (20°25'29"N - 74°57'18"W, 650 m a.s.l.); on bare ground of trail crossing sclerophyll scrub; 12/December/1997; R. Teruel; one adult female paratype ( SY, in ethanol 80%). Baracoa Municipality: Cayo Fortuna (20°14'39"N - 74°32'05"W, 330 m a.s.l.); A. R. Estrada; one adult female paratype ( IES, dry pinned) .

Diagnosis. Micropterous, with tegmina reaching posterior margin of abdominal tergite I. Size large for the genus (24–31 mm). Coloration reddish brown, unstriped.

Etymology. The specific epithet is an eponym derived from Baracoa, the main section of the orographic system, which encloses all known localities of the species (the Sagua-Baracoa Mountains).

Description (adult female holotype).

Size large for the genus (total length 30.65 mm). General coloration reddish brown, without any sharply contrasting patterns, eyes black. See figure 1 and table I.

Head (figs. 2a–c). Large, exactly as long as wide. Tegument shiny but sparsely and coarsely punctate, essentially glabrous. Vertex moderately convex in lateral view, subtriangular in dorsal view; fastigium prominent, paraboloid in dorsal view, semicircular in lateral view and strongly compressed in frontal view. Eyes large, suboval and prominent; ocelli minute. Genae moderately convex in frontal view. Antennae standard for Acrididae in size and shape, with 21/21 flagellomeres; scapus subcylindrical, depressed, longer than wide (ratio = 1.5), oval in cross-section, essentially glabrous; pedicel about half the length of scapus.

Thorax (figs. 2d–e, 3a–b). Tegument essentially glabrous, shiny but densely and coarsely punctate. Pronotum (figs. 2d–e) trapezoidal and strongly tapering anteriorly in dorsal view, only slightly wider than long; anterior margin almost straight, posterior margin coarsely crenulate and shallowly incised medially, lateral margins S-shaped; median keel finely costate, lateral keels coarsely crenulate and deeply incised by the three transverse grooves. Mesonotum 2.4 times shorter than metanotum, wider than long (ratio = 4.5), with tegument smooth and shiny; with a pair of tegmina which are narrow, spatulate and rather short compared to more typical grasshoppers, i.e., reaching posterior margin of abdominal tergite I. Metanotum wider than long (ratio = 2.1), with the same basic sculpturation as pronotum (figs. 3a–b).

Legs (fig. 1). Covered all over by thin setae. Profemur slender, cylindrical and unarmed; protibiae of exactly the same length as profemur, very slender and straight, ventral surface with 4:4 / 4:4 subapical spines and two medium-sized apical spurs. Mid legs very similar to forelegs, but mesotibiae with 3:4 / 4:3 subapical spines. Metafemur robust, 1.1 times longer than metatibiae, oval in cross-section; metatibiae with 7:7 / 7:7 subapical spines and five apical inward-curved spurs: one laterodorsal (medium-sized), one lateral (medium-sized), two lateroventral ones (large, asymmetrical, right spine larger), and one ventral (large).

Abdomen. Large and slender (conspicuously narrower than pronotum), subcylindrical and evenly tapering posteriorly. Tegument smooth and shiny, with small scattered setae. Tympanic organ oval-elongate, located laterally on segment I. Supra-anal plate (fig. 3c) longer than wide (ratio = 1.2), paraboloid, sparsely setose. Cerci very short, conical and densely covered by thin setae. Subgenital plate (fig. 3e), longer than wide (ratio = 1.6), paraboloid; anterior margin shallowly concave, lateral margins shallowly convex, posterior margin convex and with a strong spade-shaped median projection, basally flanked on each side by deep notches. Ovipositor in lateral view: each valve of the dorsal pair with dorsal surface convex, with five small dorsal crenulations, and apically curved upwards; each valve of the ventral pair with ventral surface convex, with one small ventral crenulation and apically curved downwards. See figures 1, 3c–e and table I.

Male: Unknown.

Variation. Size varies from 24.00– 30.65 mm in the types, with slight variations in proportions and relative measurements of several structures (tab. I).

Coloration is essentially identical in the four types. The few minor differences are all artifacts of differential preservation.

The number of antennal flagellomeres is 21/21 except in the paratopotype, with 22 in its single preserved antenna (left).

The subgenital plate in the paratypes from Ojito de Agua and Piedra La Vela differs from holotype: the median projection of the posterior margin is lanceolate to triangular and lacks both laterobasal notches.

Comparisons. A. baracoae n. sp. is easily distinguished from the three Hispaniolan members of the genus by the following characters: 1) Size larger. 2) Coloration unstriped reddish brown. 3) Tegmina present.

Distribution (fig. 4). This species is known from three localities, scattered across the Sagua-Baracoa Mountains of northeastern Cuba.

Ecological notes. According to its original label, the holotype of A. baracoae n. sp. was captured on the vegetation.

The paratype from Piedra La Vela is the only specimen with complete ecological data. According to the field notes provided by its collector (R. Teruel, pers. comm.), it was found at early afternoon in a sunny but cold winter day, on the bare ground of a trail crossing the core of a sclerophyll scrub (locally known as "charrascal"), which is a very peculiar vegetation type endemic to the Sagua-Baracoa Mountains (fig. 5). Despite receiving more than 2,000 mm of annual rainfall, it is hot, dry and xerophytic due to the edaphic drought (the water does not penetrate the hardened laterite and serpentinite soil and evaporates quickly).

The three known collecting sites are located deep inside intramontane valleys (fig. 4b), at medium altitudes ranging from 300–700 m a.s.l. According to Reyes & Acosta Cantillo (2005), three main adjacent vegetation types are dominant in these mountains: pine forest, rainforest and sclerophyll scrub (fig. 5).

General remarks

This new species fits the current diagnosis of Acridurus in all characters given by Perez et al. (1995), with the single exception of possessing tegminae (absent in the three Hispaniolan species). This character alone does not support the separation of the single Cuban species into a distinct genus as previously suggested by Yong & Perez-Gelabert (2014: 412), because it is obviously useless at this taxonomic level. It is well-known that the complete range of variation from entirely apterous to full-winged occurs in many American genera of Acrididae , e.g., Boopedon Thomas, 1870 , Melanoplus Stål, 1873 , Orphulella Giglio-Tos, 1894 , Phaedrotettix Scudder, 1897 , Philocleon Scudder, 1897 and Proctolabus Saussure, 1859 ( Fontana et al., 2008; S. Yong pers. obs.). During this study were also examined paratypes of both sexes of all Hispaniolan species of Acridurus (see below), and females were found to differ from A. baracoae n. sp. only in standard species-level characters such as size, coloration and minor body proportions.

It is worth mentioning here that the current generic diagnosis of Acridurus is not at all satisfactory and needs a thorough revision, which is already in progress (S. Yong, in preparation). Perez et al. (1995: 162–163) based the genus on nine characters, but three of them (33%) involve coloration, which is of little validity at this taxonomic level. As discussed above for tegminae, coloration is so highly variable within most genera of Acrididae that it lacks diagnostic value, in some cases even at species level.

Similarly, the distinction of the Hispaniolan species of the genus is not satisfactory either. The 22- year old original descriptions by Perez et al. (1995) still remain the only available, and are very short, incomplete and based on few characters, part of them too weak and difficult to interpret, especially because no thorough study of variability was attempted therein. These problems are especially evident on table 2 of that paper ( Perez et al., 1995: 163): it is titled " Comparison of Acridurus species (males) " [sic], but columns pertaining to A. yayitas and A. neibanus are identical for all five characters, thus, their distinction is impossible. Another example is that the original " description and diagnosis " [sic] of A. yayitas explicitly mentions female characters, but the types-series includes only two males and five juveniles ( Perez et al., 1995: 164).

Comparative material examined

1. Acridurus neibanus . One adult male and one adult female paratypes (MNHN-SD). Each specimen bears two identical labels. Label # 1 (rectangular, white card): "Hispaniola (D.R.) Independencia Prov. Los Pinos del Eden 3.xii.199 (Perez et al)" [sic, the correct date according to the original description is 23.xii.1993]. Actually: Dominican Republic: Independencia Province: beginning of road from La Descubierta to los Pinos del Edén; 23/ May/1993; D. E. Pérez-Gelabert, G. Dominici, B. Hierro (see Perez et al., 1995: 165). Label # 2 (rectangular, white card with yellow stripe along left edge): " PARATYPE Acridurus neibanus Perez et al. 1995 ". See fig. 6a herein.

2. Acridurus robustus . One adult male and one adult female paratypes (MNHN-SD). Each specimen bears two identical labels. Label # 1 (rectangular, white card): "Hispaniola (D.R.) Pedernales Prov. Parque Nacional Jaragua 200 N of Playa Inglesa S of S end of Laguna de Oviedo 27-28.v.1993 Perez, Dominici & Hierro". Actually: Dominican Republic: Pedernales Province: Parque Nacional Jaragua, rocky cliffs of Playa Inglesa, south of south end of Laguna de Oviedo; 27–28/May/1993; D. E. Pérez-Gelabert, G. Dominici, B. Hierro (see Perez et al., 1995: 163). Label # 2 (rectangular, white card with yellow stripe along left edge): " PARATYPE Acridurus robustus Perez et al. 1995 ". See fig. 6b herein.

3. Acridurus yayitas . One adult male and one adult female (MNHN-SD). Each specimen bears two identical labels. Label # 1 (rectangular, white card): "Hispaniola (D.R.) Cerca de Ocoa 2 km carr. Los Martinez (D. Perez)", actually Dominican Republic: Peravia Province: km 2 of road to Los Martínez; 29/September/1996; D. E. Pérez-Gelabert (see Pérez-Gelabert, 2000: 338). Label # 2 (rectangular, white card with yellow stripe along left edge): " PARATYPE Acridurus yayitas Perez et al. 1995 " [sic]. Note: both specimens are not part of the type-series of A. yayitas and not even topotypes. As originally declared in the original description, the holotype male and six paratypes (one male and five juveniles) all have completely different data: Dominican Republic: Azua Province: Las Yayitas; 225 m a.s.l.; 22/May/1993; D. E. Pérez-Gelabert, G. Dominici, B. Hierro (see Perez et al., 1995: 164). See fig. 6c herein.

Figures

Figure 1. Acridurus baracoae n. sp. Adult female holotype, full-body views: a) dorsal; b) lateral; c) ventral. Scale bar in centimeters, with millimeter subdivisions.

Figure 2. Acridurus baracoae n. sp. Adult female holotype, close-up views: a) head, dorsal; b) head, lateral; c) head, ventral; d) pronotum, dorsal; e) pronotum, lateral.

Figure 3. Acridurus baracoae n. sp. Adult female holotype, close-up views: a) mesothorax, tegminae, metathorax and abdominal tergite I, dorsal; b) mesothorax, tegminae, metathorax and abdominal tergite I, lateral; c) apex of abdomen, dorsal; d) apex of abdomen, lateral; e) apex of abdomen, ventral.

Figures 4-5. 4 a) The Greater Antilles, showing current geographical distribution of the genus Acridurus. b) Easternmost Cuba, showing precise locality records of Acridurus baracoae n. sp.: type locality Ojito de Agua (1), Piedra La Vela (2), Cayo Fortuna (3). 5 Two views of the habitat of Acridurus baracoae n. sp.: a) sclerophyll scrub at Piedra La Vela; b) rainforest at Cayo Fortuna. Photos courtesy Rolando Teruel.