Melanogryllacris atrata atrata ( Walker, 1869 )

Ingrisch, Sigfrid, 2018, New taxa and records of Gryllacrididae (Orthoptera, Stenopelmatoidea) from South East Asia and New Guinea with a key to the genera, Zootaxa 4510 (1), pp. 1-278 : 215-216

Melanogryllacris atrata atrata ( Walker, 1869)

Figs. 74 J–K, 76K–N

Holotype (male, not seen): Borneo , Sarawak, (Oxford UMO according to Griffini 1910).

Material examined. Indonesia: Kalimantan Timur, Midden Oost Borneo 155, 10.x.1925, leg. H.C. Siebers— 1 female (Wien NHMW) . East Malaysia: Sabah, Mt. Kinabalu NP, Poring, Topou , elev. 500–700 m (6°5'N, 116°33'E), 24.ii.1997, coll. A. Floren (SeWaI 5B5 NL 7B5 NL 7 Fog 3)— 1 female (Bonn ZFMK) . Malaysia: Selangor-Pahang , [Ile Gep] should be “Semangko Pass“, 610 m, 1–31.i.1915 — 1 male (holotype of M. a. conjuncta) (London BMNH) .

Diagnosis. M. atrata is characterized by the dark coloration. Tegmen and hind wings are black while most of the cross-veins of tegmen are white. In the female, the short ovipositor with widened base but otherwise slightly down-curved valves is also characteristic for the species and genus ( Fig. 74J ).

Description. Medium sized species. Head: Face ovoid; forehead nearly smooth with faint transverse riffles in lower area; fastigium verticis wider than scapus; ocelli indistinctly separated from fastigium frontis by a curved suture; ocelli little distinct; subocular furrow distinct ( Fig. 76N ). Abdominal tergites two and three each with two rows of stridulatory pegs (2, 6; 7, 19; n = 1; Fig 76L ).

Wings surpassing abdomen and reaching about midst of stretched hind tibia ( Figs. 74K , 76K ). Tegmen: Radius with two branches, both forked near tip; in the male type of M. a. conjuncta and in the female from Kalimantan, RS just after arising from R fuses with MA for about two cell lengths and then separates again, in the female from Kinabalu there is no connection between both veins; media anterior free from base, single branched or fused in about mid-length for about two cells lengths with RS; MP and CuA with common stem, dividing behind basal third, and the anterior branch divides again about at mid-length resulting in three branches, MP, CuA1 and CuA2; cubitus posterior undivided, free throughout; with 4 anal veins. Legs: Hind femur with rather strong spines on both ventral margins, the last internal spine markedly larger than the preceding. Hind tibia with a pre-apical spine on both ventral margins.

Coloration. General color black; face, central areas of vertex and pronotum, thoracic sternites, coxae and basal two thirds of all femora brown or of light color. Face yellowish brown, marbled with lighter and darker spots and flecks. Tegmen blackish brown; veins and veinlets in about basal half light greyish, in apical half veins dark brown, veinlets of lighter color; hind wing blackish brown with dark veins and veinlets, partly with light cross-veins. The female from Mt. Kinabalu that had been originally conserved in alcohol is of lighter color: the basic color is medium to dark brown, the pronotum has only the margin black, and the black color of the genicular area of all legs is less extended. The tegmen is medium brown but almost transparent along fore and hind margins. The hind wings have a light brown infumation, dark brown veins and medium brown cross-veins ( Fig. 76K ).

Male. Subgenital plate (type of M. a. conjuncta) wide at base, strongly constricted before mid-length and projecting central area with moderately converging lateral margins; apical margin subtruncte; styli small and thin, inserted at medial constriction of plate, their tips not reaching half the length of the median process. See also extensive descriptions in Griffini (1910) and Karny (1926a).

Female. Seventh abdominal sternite larger than preceding sternites, black; in middle of hind margin with a small yellowish modification consisting of a pair of lateral pits with swollen margins and a short medial furrow with swollen lateral margins, open anteriorly and terminating posteriorly in a small elevation. Subgenital plate black, with medial furrow and converging lateral margins, base little excised to fit the modification of the seventh sternite, apex slightly bilobate ( Fig. 76M ). Base of ovipositor with oval swelling at very base; basal to subbasal area stout and thick, black. Ovipositor behind subbasal area narrowed, yellowish brown and with concave ventral margin; tip subacute ( Fig. 74J , 76M ).

Measurements (1 female from Kinabalu).—body w/wings: 36; body w/o wings: 29; pronotum: 6; tegmen: 27.5; hind femur: 15.5; tegmen width: 10.5; antenna: 110; ovipositor: 7.5 mm. For variation see Karny (1926a).

Discussion. Melanogryllacris is so far a monotypic genus. However, two varieties have been named by Karny (1926a and 1928e). Since they were named before 1961, they are currently treated as subspecies (OSF 2017). However Karny's (1926) text suggests, that he intended to name an entity below the subspecies level. He explicitly mentions that he did not find any difference between the three males of M. atrata he studied, except that in the male that he named var. conjuncta the media (= media anterior as used in this paper) fused for a short distance with radius sector while in the other two males that he later ( Karny 1928e) named var. disjuncta , the media was free over the whole length. Regarding the individual variability with regard to this character in Gryllacrididae , I would not pose much importance on this character. However, a re-investigation of the specimens concerned and including Walkers' type from Sarawak, with emphasis on a detailed examination of the male abdominal appendages, would be necessary to settle this question and eventually draw any taxonomic consequences. It would also be necessary to re-investigate Walkers' type of M. atrata for the venation, as that character has not been studied by Griffini (1910).

The two females studied agree in general characters with the redescription of the male holotype of M. a. atrata by Griffini (1910).

Figures

FIGURE 74. Genus Melaneremus: A–D, M. fruhstorferi (Griffini, 1914) male holotype (A), female allotype (B) and male from Hoang Lien (C–D), E–H, M. sikkimensis sp. nov. holotype; I, M. atrotectus (Brunner, 1888) male holotype.—J–K, Melanogryllacris atrata (Walker, 1869) female in NHMW.—Habitus lateral view (A–B, I–J), habitus dorsal view (C, E, K), face (D, H), anterior area of body with head, pronotum and thorax (F), lateral view on reduced wings (G).

FIGURE 76. A–J, Genus Metriogryllacris: A–E, M. (M.) amitarum (Griffini, 1914) female syntype (A–C), male syntype (D), and male from Tam Dao (E); F–G, M. (M.) permodesta (Griffini, 1914) female holotype; H–J, M. (Xiphilarnaca) xiphiura (Karny, 1928) syntype.—K–N, Melanogryllacris atrata (Walker, 1869) female from Kinabalu.—Face (A, F, H, N), habitus dorsal view (C, E, I, K), habitus lateral view (B, D, G, J), stridulatory pegs on second and third abdominal tergites, front is left (L), female abdominal apex with ovipositor and subgenital plate (M).