Dentotibium Cadena-Castañeda & Gomez-Morales, 2024

Cadena-Castañeda, Oscar J., Gomez-Morales, Diego A., Acevedo-Charry, Orlando & Benavides-López, Jose Luis, 2024, Studies on Neotropical Pseudophyllinae: Integrative description of Dentotibium gen. nov., and of a toothed foretibia katydid (Orthoptera: Tettigoniidae) that sings from burrows in branches, Journal of Orthoptera Research 33 (2), pp. 267-280 : 267-280

Dentotibium Cadena-Castañeda & Gomez-Morales gen. nov.

Type species. —

Dentotibium ramucantoris gen. nov. et sp. nov. by original designation and monotypy.

Generic diagnosis and comparison. —

Dentotibium gen. nov. is close to Nastonotus Bolívar, 1890, as both genera are brachypterous and have tubercles over the dorsal margins of the foretibiae. Nevertheless, Nastonotus differs from Dentotibium gen. nov. by its fronto-genal suture being very marked and its face being very rugose, unlike the latter, which has the whole head smooth and lacks sutures that delimit the face from the rest of the cephalic capsule. Furthermore, Nastonotus species have three black stripes on the vertex, the main one going over the medium line of the pronotum, while Dentotibium gen. nov. lacks these lines. The tenth tergite in Nastonotus is elongated, and the cerci are distally elongated, very slim, sclerotized, and acuminate. The new genus has only the preapical ventral spine, which is robust and hook-shaped.

Trichotettix Stål, 1873 is also similar to the new genus but differs in morphology. The surface of the pronotum and legs of Trichotettix is densely covered by thick hairs, while Dentotibium gen. nov. has few and thin hairs. Trichotettix does not have ventral spines on the fore and middle femora or the dorsal tubercles of the foretibia, both of which occur in the new genus. The cerci of Trichotettix males are thin and armed with two sclerotized spines of similar size, while Dentotibium gen. nov. has only one preapical spine curving downward. As for the internal genitalia, the ti of Trichotettix is well-sclerotized in a peduncular structure, while the ti of the new genus is membranous and barely differentiates itself from the rest of the genital structures. Trichotettix females have a wide ovipositor, and the last sternite does not have modifications or folds, as occurs in Dentotibium gen. nov.

Other brachypteran Cocconotini genera that resemble Dentotibium gen. nov. include Nannotettix Redtenbacher, 1895 , and Natagaima Beier, 1960 , which are also distributed on the eastern slope of the Colombian Andes Mountain range and its inter-Andean valleys. These genera differ from Dentotibium gen. nov. in that they are more slender and are a reddish-brown or ocher color; both genera have a black midline that crosses the pronotal disc. Nannotettix and Natagaima do not have dorsal denticulations of the foretibia. The last sternite of the females is not modified, and the ovipositor is also more slender as well, in contrast to females of the new genus.

Dentotibium gen. nov. also resembles the genus Gnathoclita Haan, 1843 , of the tribe Eucocconotini , particularly the brachypteran species. The main differences between both genera are the same as those between the new genus and Trichotettix (except for the hairs on the pronotum and legs and the shape of the cerci, which are unique to Trichotettix ). The most notable difference is the modification and lengthening of the mandibles of Gnathoclita males projecting forward, which does not happen in the new genus.

Etymology. —

The name of the genus derives from the conjunction of the Latin “ dento ” and “ tibium ” in reference to the teeth present on the dorsal margin of foretibiae. The gender of this name is being established as neuter.

Description. —

Mid-sized (body length 21–36 mm) and moderately robust body (Figs 1, 4). Coloration. Body coloration predominately ocher, with black stripes in head and pronotum; tegmina black with yellow veins (Figs 1, 4). Head. Globose (Fig. 1 A, B), space between antennal sockets as wide as half of width of antennal scape; fastigium slightly raised, narrow, and with ocelli located on each side (Fig. 1 C); rugose cephalic capsule surface; scape and pedicel without spines; maxillary palpi moderately elongated (Fig. 1 D); mandibulae symmetric and with similar development in both sexes. Thorax. Pronotum granulose (Fig. 1 A, D), anterior border curved and projected forwards; sulci divide the deep and present zones of the pronotum (Fig. 1 B); lateral lobes of pronotum quadrangular, humeral sinus not developed (Fig. 1 D). Sternum. Prosternum armate, with two little conical spines; mesosternum and metasternum wider than long, with rounded lateral lobes lacking spines or tubercles not making contact over ventral margin; mesofurcal groove narrow with the two holes close to each other. Wings. Brachypterus, fore and hind wings covering near the half of the abdomen (Figs 1, 2 A – E). Legs. Moderately robust, with two or three spines on the ventral side of the fore and mid femur, less when compared to other genera of the tribe. Fore coxae armate, with a conspicuous dorsal spine (Fig. 1 D); all the coxae ventrally unarmed. Foretibia armate dorsally, with two rows of tubercles, each one over each dorsal border from the tympanum to the apex (Fig. 1 C, D). Abdomen cylindrical (Fig. 2 F – H), tenth tergite and epiproct without modification in males (Fig. 2 F, G) and females (Fig. 5 D); male cerci robust and armed with a preapical spine (Fig. 2 F). Male subgenital plate almost as long as wide and with articulate styli (Fig. 2 H). Female’s last abdominal sternite modified, with folds in the apex (Fig. 5 F, G). Ovipositor robust, almost as long as the hind femur (Fig. 5 D, E). Female subgenital plate without modifications (Fig. 5 G). Male genitalia. Predominantly membranous, ti moderately sclerotized over the posterior margin, vdl differentiated and wavy in the apex (Fig. 3).

Distribution. —

Mid and highlands of Boyacá, Colombia, between 1600 and 2300 m above sea level.

Comments. —

This new genus can be easily confused with Trichotettix , especially due to the coloration of the type specimen of Trichotettix pilosula Stål, 1873 , which has a color pattern similar to that of D. ramucantoris gen. nov. et sp. nov. However, the specimens of T. pilosula studied by Montealegre-Z and Morris (1999) have a reddish-brown color but fit the morphology of the type specimen studied by the authors. The most likely reason for this color difference is that the type specimen, preserved in alcohol, lost its original coloration. It is common for reddish specimens preserved in alcohol for a long time to turn into various shades of ocher. In contrast, the ocher coloration of the studied specimens of D. ramucantoris gen. nov. et sp. nov. was preserved by keeping the specimens alive until description and, subsequently, in dry conservation in entomological collections.

Trichotettix nuda Beier, 1960 was originally described based on a subadult female that was eventually found to correspond to an undescribed genus from the paramos surrounding Bogotá city (Colombia’s capital). For this reason, T. nuda is not considered to belong to Trichotettix and will be reassigned outside of Cocconotini in a forthcoming description of the new genus and the adult stages (Cadena-Castañeda in prep.). Thus, we rule out this species as being related to D. ramucantoris gen. nov. et sp. nov.