Adelosgryllus xambioa Merlo & Castro-Souza & Junta & Ferreira 2022, n. sp

Adelosgryllus xambioa n. sp. (Figures 25–29, 30–37, 38–40, 41–42, 43–45, Table 1) Material examined. Holotype ♂, code ISLA 66153, Brazil, Tocantins state, Xambioá municipality, Explosão cave (6º 25’ 19.301” S; 48º 24’ 34.880” w), 22.ii.2018, Ferreira R.L. leg. Holotype condition: right tegmen and legs detached, and maintained in holotype tube. Distribution. Known only to Explosão cave (6º 25’ 19.301” S; 48º 24’ 34.880” W) municipality of Xambioá, Tocantins state, Brazil. Etymology. The specific epithet refers to the municipality of Xambioá, Tocantins state, where the species was found. Diagnosis. Combination of the following characteristics: superior inner base of paramere 1 more rounded (Ps.P1, Figs 26 and 28) (compared to A. lucifugus and A. ferratilis n. sp.), inner basal margin from paramere 1 with dilatation more pronounced (ventral, diagonal and front view) (Ps.P1.p, Figs 25, 28 and 29) (compared to A. lucifugus and A. ferratilis n. sp.); paramere 2 slightly dilated toward paramere 1 (dorsal view) (Ps.P2, Fig. 25); rami elongated and poorly sclerotized (R, Figs 25, 27 and 29); ectophallic fold poorly sclerotized, lateral border slightly towards outside (Ec.F, Fig. 26); endophallic sclerite underdeveloped (End.Sc, Fig. 26). Description, male holotype. Similar to A. ferratilis n. sp. with the following differences: body dark brown with head orange (in vivo) (Fig. 45) (body pale dark brown and head pale yellow after fixation in ethanol 70%) (Figs 30–37); compound eyes were depigmented due to ethanol fixation (comparation between figs 30 and 45, same individual); pronotum pale dark brown, poorly marked with a whitish vertical and without horizontal median band, two small symmetrical diagonal white spots near the distal portion (Fig. 32); Right tegmen: less sclerotized, covering the first five abdominal tergites (Fig. 33). Lateral field (in lateral view, Figs 33 and 42): diagonal vein (DV), subcostal (SC) and radial (R) with poorly marked irregular veins. Field (in ventral view, Fig. 41): harp with a median-longitudinal vein (L) more toward out, and four crossed veins (Hcv), the first forms a small cell, below curbital 2 (Cu2); mirror with a narrower proximal part of triangular shape, with two crossed veins (Mcv), unbranched; subgenital and supra-anal plates dark brown, shapes changed after fixation in ethanol (Figs 35–37); stridulatory file with 94 teeth. Observations in holotype phallic sclerites: Similar to A. ferratilis n. sp. with the following differences: phallic complex less sclerotized (Figs 25–29). Pseudepiphallic: superior inner base of paramere 1 more rounded (ventral view) (Ps.P1, Fig 26), inner basal margin from paramere 1 with a dilatation more pronounced (ventral, diagonal and front view) (Ps.P1.p, Figs 25, 28 and 29); paramere 2 slightly dilated toward paramere 1 (dorsal view) (Ps.P2, Fig. 25); rami poorly sclerotized (R, Figs 25, 27 and 29). Ectophallic invagination: posterior projections poorly sclerotized and quadrangular-shaped (similar to A. lucifugus) (Ec.Pr, Fig. 26); ectophallic fold poorly sclerotized, lateral border slightly towards outside (Ec.F, Fig. 26). Endophallus: endophallic sclerite underdeveloped (End.Sc, Fig. 26). Ecological Remarks The single observed specimen of Adelosgryllus xambioa n. sp. was found in the Explosão cave, which is a marble cave with 1203 meters of horizontal projection. A quarry that used to remove marble from the outcrop led to the collapse of the main cave entrance. Therefore, in order to access the cave, one should enter through a small opening located at the base of the outcrop, leading to a very narrow passage (Fig. 43). The floor along most part of the cave is covered with sediments (Fig. 44), although a few fallen blocks are also present. The organic resources in the cave are especially bat guano produced by several bat species although deposits produced by hematophagous bats are the most common. Additionally, vegetal debris transported by water during strong rains also occur in some areas. The cave is devoid of any regular water flow, but several areas can be partially flooded during the rainy period. The single collected specimen was observed freely walking on the cave floor (Fig. 45), close to a guano pile. It is important to mention that the cave was not entirely surveyed during our sampling, since a flashflood occurred forcing the team to quickly leave the cave. Accordingly, there is no information regarding the size of the species’ population and its density inside the cave. The region presents a climate Aw5 (according to the Köppen classification system), with an average annual precipitation of 1558 mm and an average annual temperature of 26.3ºC. The external area is altered, especially due to the removal of the natural vegetation and its replacement by Eucalyptus plantations. However, secondary forest surrounds the outcrop where the cave is located. As for the other species herein described, the epigean environments surrounding the cave were not sampled, so it is currently impossible to determine the habitat preference for this species. It is important to mention that despite the fact that the species was only found inside a cave, it does not exhibit any troglomorphic traits, thus not being a cave-restricted species. Since the external area was not sample, it is likely that the species’ distribution is much wider than currently known.