Bioacoustics of Diplospinula serrana

Description. In addition to the characters of the genus: medium size (body length 16–23 mm ), in comparison with Fiancogryllacris , Camposgryllacris and Abelona Karny. General coloration yellow ochre, almost uniform in living specimens ( Figs 1B, D ); fixed specimens with dorso-lateral bands medium brown, from disc of pronotum to last tergite, median region light to yellowish brown (fig. 2). Head. In dorsal view, fastigium 2x wider than scape ( Figs 2C, D ). Dark brown markings above eyes ( Figs 2 , 3 ); dark brown vertical line on subocular suture ( Figs 3A, D ); Maxillary and labial palps light to yellowish brown. Pronotum . Pronotum disc central area light to yellowish brown, dark brown laterally in cephalic and caudal margins ( Fig. 2 ); cephalic margin slightly convex, caudal margin almost straight ( Fig. 2C, D ); lateral lobes ventral margins rounded ( Figs 2A, B ). Legs . TI and TII spurs yellowish; TI spurs 5/5; TII spurs: 4/5; TIII spines dark brown. Male. Anterior margin of tergite X with plate-shaped process sclerotized, light brown medially, laterally surrounding cerci ( Fig. 2C ). Subgenital plate broad, wider than long; posterior margin central area with two projections short, with setae at base ( Fig. 3C ). Paraproct with small setae ( Fig. 3C ). Titillator broad, in form of two large lobes (the lobes are absent in Astyloplatum Cadena-Castañeda, Castañeda, Garay & García García ), with distinct micro spines ( Fig. 4 ). Female. Sternite VII posterior margin slightly projected in lateral view. Epiproct slightly elongated. Variation. Observed in some specimens: median region and spurs of TI and TII light to dark brown; anterior region of TIII and apex of cerci dark brown; male tergite IX without process on central area of posterior margin; ovipositor dark brown. Measurements (mm). Males (n=5), mean (range): BL, 22.27 (20.6–23.95); PL, 4.05 (3.90–4.20); PFL, 9.06 (8.52–9.60). Females (n=3), mean (range): BL, 18.65 (16.64–20.66); PL, 4.04 (3.85–4.24); PFL, 9.34 (8.62–10.06); OL, 8.82 (8.63–9.01). Taxonomic remarks. Diplospinula gen. nov. was compared with all known Brazilian apterous/micropterous gryllacridids: Camptonotus americanus ( Bruner, 1915 ) , Fiancogryllacris rivimeridionalis Cadena-Castañeda, 2024 , and Camposgryllacris australis Cadena-Castañeda, 2024 . The main structures observed for comparisons, which have proven to be highly useful in the taxonomy of Gryllacrididae by providing informative characters, are the spurs of the tibiae (size and number), the stridulatory apparatus (number of rows), the subgenital plate (shape, especially in females), and, most importantly, the male terminalia, particularly the ninth tergite. The morphology of Diplospinula gen. nov. is similar to Fiancogryllacris , based on comparisons with the photographs of type specimens of F. rivimeridionalis and observations on undescribed species from MNRJ, differing in the following characters: number of spurs on TII, number of stridulatory rows, morphology of male terminalia, and morphology of female subgenital plate. The main character distinguishing Diplospinula gen. n ov. from Camptonotus americanus is the absence of tegmina. This contrasts with the species described by Bruner (1915) , which possesses highly reduced tegmina in the form of small, scaly lateral lobes. Furthermore, C. americanus stands out for its smaller sizer compared to other South American apterous and micropterous species (approximately 12 mm ), as well as for the 5/4 spur formula on T1 and T2. It is not possible to differentiate these taxa based on subgenital plates or the male ninth tergite, as these structures were not mentioned in the original species description. Additionally, the holotype of the species is currently lost, preventing further analysis of these structures in the type material. Cadena-Castañeda (2024) suggests the status of nomen dubium for Camptonotus americanus due to the loss of type specimens and proposes its inclusion in Fiancogryllacris , as it occurs near the known distribution of F. rivimeridionalis . However, we consider C. americanus to be a valid name because, although the type is lost, the type locality (Salto Grande, São Paulo state ) is accessible, and it is possible to collect a topotype , conduct a taxonomic study, and designate a neotype (if necessary) in a further study. Additionally, C. americanus have a very reduced tegmina, which suggests it may be more closely related to Camposgryllacris than to Fiancogryllacris . Although Cadena-Castañeda cites the presence of “alar rudiments on meso- and metanotum” in Fiancogryllacris , analysis of undescribed specimens in MNRJ, as well as photographs of type specimens of F. rivimeridionalis and the male specimen described by Cadena-Castañeda (2024) , clearly show that Fiancogryllacris is apterous, being closely related to Diplospinula gen. n ov. Diplospinula serrana gen. et sp. nov. differs from Camposgryllacris australis , based on photographs of type specimens and the original description by Rehn (1907), by the absence of tegmina, in addition to the number of spurs on tibia I and II: tibia I formula 5/ 5 in D. serrana gen. et sp. nov. and 4/ 4 in C. australis , and tibia II formula 4/ 5 in D. serrana gen. et sp. nov. and 4/ 4 in C. australis . Additionally, C. australis lacks stridulatory apparatus; this structure was not observed in the photographs of type specimens, and was not cited in the original description. According to the original description of C. australis , the subgenital plate of male and female differs from D. serrana gen. et sp. nov. ; however, these structures could not be observed in the photographs of type specimens of C. australis . Regarding the terminalia of both sexes, the differences are quite distinct. The posterior margin of the ninth male tergite of Diplospinula gen. nov. has a small process directed forward on the central edge, with the sides more developed in the form of lobes and the tip featuring a hook-shaped spine ( Fig. 3C ). The same margin in Fiancogryllacris has a pair of large processes on the lateral sides of the central edge, with one or two spines at the tip. Camposgryllacris is described only as a rounded posterior margin. Additionally, Diplospinula gen. nov. lacks a median longitudinal carina or thinner area on the dorsal region of the ninth tergite, unlike Camposgryllacris e Fiancogryllacris , respectively. The genus Displospinula gen. nov. also differs by the presence of a compressed, plate-shaped process on the anterior margin of the tenth tergite, which is replaced by a long, bifid extension projecting between the processes of the ninth tergite in Fiancogryllacris . The male subgenital plate of Diplospinula gen. nov. has a mostly subrectangular shape, with the central area of the posterior margin bilobed ( Fig. 3C ), whereas Fiancogryllacris is quadrangular, slightly divided in the middle, and Camposgryllacris has a short subgenital plate, with apex emarginate.. The female subgenital plate of Diplospinula gen. nov. is semicircular, with a rounded posterior margin, which differs from Fiancogryllacris and Camposgryllacris , which have triangular shapes.