Revision of the tusked bush-crickets (Tettigonioidea: Pseudophyllinae: Dicranostomus) with description of the hitherto unknown sexes Author Heller, Klaus-Gerhard https://orcid.org/0000-0002-3331-3228 Grillenstieg 18, 39120 Magdeburg, Germany. heller.volleth@t-online.de Author Helb, Matthias Spessartstr. 101, 63457 Hanau, Germany. text Journal of Orthoptera Research 2021 2021-06-03 30 1 87 94 http://dx.doi.org/10.3897/jor.30.62170 journal article http://dx.doi.org/10.3897/jor.30.62170 1937-2426-1-87 4050088FDDCE533EB8FF097A463DF080 4BE14BC8-A200-42AA-BC49-6DE823F62085 Dicranostomus monoceros Dohrn, 1888 Figs 1A , 2A-D , 3A, B , 4A , 5A , 6A Dicranostomus monoceros Dohrn, 1888: 362 Holotype. - PERU • ♀; Cumbasi Peruviae ad Huallagam; [Cumbaza]; MZPW. [photos in Cigliano et al. 2021 ]. Material examined. - PERU • 2♂ ; San Martin Region , Prov. Rioja , Nueva Cajamarca ; 10 Nov. 2016 ; local collector; C_ Helb 8771-C_ Helb 8772 • 1♀ , 1♂ ; San Martin Region , Prov. Rioja , Nueva Cajamarca ; Mar. 2018 ; local collector; C_ Helb 8773-C_ Helb 8774 • 2♂ ; San Martin Region , Prov. Rioja , confluente Altomayo river / Naranjos ; 8 Mar. 2018 & 25 Apr. 2018 ; local collector; C_ Helb 8775 , ♂ C_Helb8776. Remarks. - Up to now, the species was known only by the female holotype. In one female (C_Helb8773), the right foreleg is irregularly developed. Its tibia does not have a tympanic organ or dorsal black tubercles (Fig. 2 ). Redescription. - General characters as genus. Male. Fastigium frontis elongated horizontally (Fig. 2 ), mandibles each with one long (2.1-2.8 times as long as pronotum) process (tusk) (Figs 1 , 2 ; Table 1 ). Pronotum weakly granulated. Fore and mid femora ventrally with 3 spines, hind femora with 4 spines at anterior edge. Fore tibiae dorsally with 2-3 large, black, blunt spine-like tubercles at the anterior and two small tubercles at the posterior edge, ventrally with ca. 6 spines on both sides, mid tibia dorsally with 1-2 spines on posterior edge, ventrally with ca. 6 spines on both sides, hind tibia with ca. 8 spines on all edges, the dorsal larger than the ventral spines. Mirror cell in left tegmen triangular with broadly rounded distal tip, on right tegmen larger, subquadratical (Fig. 3 ). Stridulatory file on lower side of left tegmen with ca. 130 regularly spaced teeth (inter-tooth interval 20-23 µm ; Fig. 4 ; n=1 file). Supraanal plate transverse, distally rounded. Subgenital plate elongated, with ca. 1 mm long styli. Cerci with internal subapical spine and blunt apical process directed very slightly inwards. Table 1. Measurements of males and females of both species of Dicranostomus (*data from Beier 1960 ).
Species Specimen Sex Measurements (in mm)
# - body body + tusk pronotum fore femur hind femur tegmen antenna tusk ovipositor
D. monoceros type* ♀ 28 - 6.5 10.5 19 27 - 6 15
C_Helb8773 ♀ 32 35 6.5 10.5 16.5 23 120 5.5 15.5
C_Helb8771 ♂ 27 41 6 10 14.5 20 95 16 -
C_Helb8772 ♂ 32 44 7 11 16 21.5 95 15 -
C_Helb8774 ♂ 29 44 6 10.5 15.5 22 95 16.5 -
C_Helb8775 ♂ 27 40 6.5 10.5 16 21 - 16.5 -
C_Helb8776 ♂ 28.5 40 6.5 - 15.5 21 80 17 -
D. nitidus type* ♂ 30 - 7 11.5 20 22 - 14 -
Gurney 1950 ♂ 35 58 7.5 12 19 26 - 20 -
CH4220 ♂ 38 53 7.5 12 20.5 27 - 18 -
C_Helb8769 ♂ 36 47 7.5 12 19.5 26 72 13.5 -
C_Helb8770 ♀ 33 - 7.5 12 20 28.5 100 - 17.5
C_Helb8777 ♂ 36 49 7.5 13 19 27.5 68 17 -
Female. General characters as genus and male. Mandibles each with one long (0.8-0.9 times as long as pronotum), slightly upcurved process (tusk). Subgenital plate transverse, at the end straightly cut and distally slightly notched in the middle. Coloration. Head with tusks and pronotum chestnut (tusks becoming darker towards the tips); legs yellowish, but knees, tympanic organ and tubercles in the fore tibia and larger spines in all legs black. Tegmina as in D. nitidus (see below). In some animals, the anterior and central lower parts of the paranota are brighter and more yellowish than the other parts. Measurements. - See Table 1 .