Tegotettix derijei Patano, Mohagan, Tumbrinck, Amoroso et Skejo, 2021

Patano, Romeo R., Mohagan, Alma B., Tumbrinck, Josef, Amoroso, Victor B. & Skejo, Josip, 2021, Horned and spiky: Tegotettix derijei sp. n. (Orthoptera: Tetrigidae) is a peculiar new pygmy grasshopper species from Mindanao, Zootaxa 4933 (2), pp. 198-210 : 203-207

Tegotettix derijei Patano, Mohagan, Tumbrinck, Amoroso et Skejo sp. n.

(holotype Figures 5 , 6 , habitat Figure 7 )

(proposed vernacular name in English: Mindanao horned pygmy devil)

Material examined. Type material. 1♀ holotype ( Figures 5 , 6 ), 28.XI.2019. THE PHILIPPINES: Mindanao: Davao region: Marilog district: Malambo Mt. 1175 m a.s.l. ( Figure 7 ) (7.489N, 125.255E) collected from bark of a tree by R . R . Patano Jr., A. B. Mohagan and V . B. Amoroso ( CMU) .

Type material repository. Central Mindanao University, University Museum, Zoological Section, Tetrigidae Collection, Mindanao, the Philippines.

Derivatio nominis. This new neat species of pygmy grasshopper, endemic to Mindanao, is named in honor of Dr. Jesus Antonio G. Derije, President of the Central Mindanao University in the region of Bukidnon. His valuable contribution and support to the implementation of biodiversity and conservation research projects of the Center for Biodiversity Research and Extension in Mindanao (CEBREM) has helped in the development of orthopterological studies in Mindanao. The specific epitheton is genitive case noun.

Diagnosis. The species can be separated from the Tegotettix armatus species group and the T. novaeguineae species group by the exserted head and pointed eyes; by the short frontal costa that bifurcates into facial carinae between the eyes; by the shape of the fastigial horns ( Figure 6A ); and by the fact that pronotal projections are all located on the median carina of the pronotum ( Figure 5A ). From the other species of the Tegotettix cristiferus species group, T. derijei sp. n. can be separated by the pronotal morphology, because, unlike other species of the group, it has many metamedial projections, i.e., dorsal spines (moderately large PM, large MM1+MM2, MM3-MM9 same in size, minute MM10), as already stated.

Distribution and habitat. Tegotettix derijei sp. n. inhabits mountainous rainforests in the region of Davao on the island of Mindanao, the Philippines. This is a corticolous species, meaning that it dwells on bark. T. derijei sp. n. prefers bark covered in mosses (Bryophyta).

Holotype description.

General appearance. Spiky, horned, and moderately large species for the genus, 16.02 mm long from the tip of the vertex to the tip of the pronotum. Body greenish-yellowish-white with dark markings on certain parts of the body. Chitinous surfaces smooth and shiny, not armed as in other species of the genus.

Head (See Figures 6 A-D, 6G). Antennae long and filiform with 16 segments: 1 st scape, 2 nd pedicel, 3 rd, and 4 th basal segments which are almost of the same sizes as the second segment, 5 th segment almost two thirds of the size of the 6 th segment, 7 th to 11 th are central segments and are almost same in size, 12 th preapical segment is almost two times larger than the 13 th preapical segment, and 14 th to 16 th apical segments are reduced. In frontal view highly elevated fastigial horns form a U-shape together with vertex. Fastigial horns diverge upwards, covering the proximal third of the compound eye. Antennal groove positioned visibly below the lower margin of the compound eye. Scutellum obliquely projected forwards. In lateral view head, and especially eyes, slightly exserted above the pronotal discus. Whole head elongated. Tips of the fastigial horns elevated highly above the eye, surpassing its dorsal margins for about 4/5 of the compound eye height. Fastigial horns 0.42 mm high, to date the highest known in the genus. Antennal groove positioned low, 0.3 mm below the lower margin of the compound eye. Compound eyes are so exserted above the vertex that the tip of the vertex lies between them. Frontal costa is extremely short, almost unrecognizable, and diverges (bifurcates) into facial carinae just between the eyes, close to the tip of the vertex. Facial carinae diverges into 1.5 mm wide scutellum which is as wide as the bulky scapus. Lateral ocelli are placed in the level of the lower margins of the compound eyes, slightly below the bifurcation of the frontal costa and slightly above the antennal grooves. Maxillary palps elongated, hairy, and yellowish in color. In dorsal view vertex 1.5 times wider than eye. Frontal and lateral carinae of the vertex forming a V shape (similar to that found in Xistra and related genera). Median carina of the vertex distinct in the apical third. Scutellum frontally projected.

Pronotum and wings (see Figure 5 ). Dorsum of pronotum smooth, yellowish with dark stripes at anterior (surrounding sulci) and posterior parts (posthumeral area), and with black spots at the tips of each pronotal projection. Prozona reduced in comparison to other species of the genus, and with short carinae which weakly converge towards the dorsum. The pronotum has altogether 11 triangular plates/spines, all at the middle, i.e., on its median carina. Pronotal projections include one promedial ( PM) and ten metamedial projections. The first projection is the highest and is composed of fused first and second metamedial projections ( MM 1+ MM 2, in lateral view resemble a hump). The next seven projections ( MM 3– MM 9) are of almost the same size. Lastly, the 10 th metamedial projection ( MM 10) is the smallest, hardly notable, and is situated almost at the pronotal apex. Shoulders smooth and elongated, not armed. Infrascapular area small and narrow, almost indistinct, much narrower than the developed and wide lateral area. Ventrolateral projections absent, tips of the paranota obliquely truncated. Tegminal and ventral sinuses present. Tegmenula (fore wings) elongated, black with yellow spot on the very tip. Alae (wings) dark and reaching the tip of the pronotum, but not surpassing it.

Legs (see Figures 5 and 6E, 6F, 6J, and 6K ). Dorsal margin of the fore femora finely serrated and slightly undulated, ventral margin with weak undulation. Mid femora with dorsal and ventral margins serrated, with strong undulations at the proximal and middle, and with strong genicular tooth at distal end. Hind femora about three times as long as wide; with undulations in the middle of the dorsal and ventral margins. External median area is notable and in dorsal view has ridges visible as projected tubercles. Genicular and antegenicular teeth large and sharp. Pulvilli of the hind tarsi obliquely right-angled, not sharp. First (proximal) pulvillus is the shortest and most rounded, while two distal ones are longer and more angulated. Femora have yellow-green basis, with darker patches as markings. Hind tibia yellowish in color. Fore, mid, and hind tarsi are yellowish, with dark apices.

Abdomen (see Figures 6 H , GI). Abdomen of the holotype is smooth, generally yellowish-green in coloration, but with darker markings all over itself. The widths of 1 st to 5 th abdominal segments range from 0.9 to 1.2. Subgenital plate in female has triangular excision on the tip, giving it a bilobate appearance. Ovipositor elongated, dorsal and ventral valvae armed with about six strong teeth each.

Measurements of the holotype are shown in Table 1 , compared with other species of the genus.

Male unknown.

Figures

FIGURE 5. Female holotype of Tegotettix derijei sp. n., with denoted pronotal projections (PM—promedial, MM—metamedial). The specimen is deposited in the Central Mindanao University, the Philippines. A) lateral and B) dorsal view. Photographed by Romeo R. Patano Jr.

FIGURE 6. Morphological details of Tegotettix derijei sp. n. (holotype, female).A) head in frontal view, B) head in dorsal view, C) head in ventral view, D) head and prozona in lateral view, E)—fore femur, F)—mid femur, G) antenna, H) abdomen tip in lateral view, I) abdomen tip in ventral view, J) hind femur, K) hind tibia and tarsus. Photographed by Romeo R. Patano Jr.

FIGURE 7. Type locality and habitat of Tegotettix derijei sp. n. A) View on Mt. Malambo, Barangay Datu Salumay, Marilog District, Davao City, Philippines, B) habitat on which the holotype specimen was collected in a montane tropical rainforest (about 1,175 m a.s.l.). Photographed by Romeo R. Patano Jr.