Gonatoxia furcata C. Hemp

Hemp, Claudia, Heller, Klaus-Gerhard, Warchalowska-Śliwa, Elzbieta & Hemp, Andreas, 2016, Spotted males, uniform females and the lowest chromosome number in Tettigoniids recorded: Review of the genus Gonatoxia Karsch (Orthoptera, Phaneropterinae), Deutsche Entomologische Zeitschrift 63 (2), pp. 271-286 : 275-277

Gonatoxia furcata C. Hemp sp. n.

Holotype male.

Tanzania, Morogoro District, Udzungwa Mountains, National Park Headquarters, Mangula Gate, 300 m, lowland wet forest, July 2015. Depository MfN.

Paratype female, same data as holotype but March 2015. Depository MfN.

Further paratype material.

3 females, same data as holotype, May and June 2016 (collection C Hemp). 1 male (in alcohol), Tanzania, Iringa Region, Mufindi District, Udzungwa Scarp Forest Reserve, 08°31.5'S 35°53.9'E, 750 m, March 1996, McKamey et al. leg., depository ZMUC.

Diagnosis.

Females of Gonatoxia maculata , Gonatoxia immaculata and Gonatoxia furcata sp. n. are very similar. Differences are seen in the general coloration especially when specimens are alive. Gonatoxia maculata and Gonatoxia helleri sp. n. females are of lighter green colour while those of Gonatoxia immaculata and especially Gonatoxia furcata sp. n. are darker green and the tegmina shiny (Fig. 2B, C, D). The subgenital plate in Gonatoxia maculata is not as broad as those of Gonatoxia helleri sp. n., Gonatoxia immaculata and Gonatoxia furcata sp. n. (Fig. 9A, B, C, D) but the differences are not very pronounced. Lateral at the base of the ovipositors a bowl-like structure is present in all Gonatoxia species (arrows Fig. 7). In Gonatoxia maculata this bowl-like structure is large and more deeply excavated than in Gonatoxia immaculata (Fig. 8A). In Gonatoxia furcata sp. n. inside the “bowl” a hump is located at the upper part and the lower margin is not hairy as in the other two species. The bowl-like structure in Gonatoxia helleri sp. n. is very shallow and not as setose (Fig. 8B). Further Gonatoxia immaculata females are smaller than those of Gonatoxia maculata and Gonatoxia helleri sp. n. while Gonatoxia furcata sp. n. females are generally larger than those of the other three species.

Males are distinguished when comparing the outer genitalic morphology. In Gonatoxia maculata the cerci are evenly tapering to their apices, the tips wearing a short and straight serrated ridge (Fig. 3B) while in Gonatoxia immaculata the tips of the cerci wear a longer and curved serrated ridge (Fig. 3D, E). Gonatoxia helleri sp. n. has similar built cerci as Gonatoxia maculata but instead of a serrated ridge (Fig. 3B) a smaller ridge or 1-4 closely clustered teeth are located at the tips. In Gonatoxia furcata sp. n. the tips of the male cerci are elongated, scythe-shaped with a very long serrated ridge (Fig. 3G, H, I). Males of all four species have maculae on the tegmina (Fig. 15). In Gonatoxia maculata these white patches can be small or large and conspicuous, most specimens had 3-6 of these markings. In the known specimens of Gonatoxia immaculata the patches were orange-brown (Fig. 14, 15C). The maculae of Gonatoxia furcata sp. n. resemble those of Gonatoxia immaculata , being orange-brown. Gonatoxia helleri sp. n. usually has small longish white maculae and mostly not more than 2-4 (Fig. 15B, 16A).

Description.

Male. Color dark and shiny green, with few ivory patches on tegmina; tergites of abdomen vivid yellow, venter whitish to light green; fore femora dorsally light brown, same colour as tarsi, thus similar to Gonatoxia immaculata . Head and antennae. Antennae thin, green, surpassing tegmina by about 1/3. Eyes round, green, with light stripe beginning in eyes, running over the head getting yellow along lateral edges of the pro notum. Thorax. Pronotal disc flat with sharp lateral edges, anterior margin v-shaped incurved, posterior margin of disc broadly rounded as described for genus ( Karsch 1889). Lower margin of pronotal lobes broadly rounded, deeper than long, with sharp edge where wings are inserted. Tegmina broad, posterior end broadly truncate. Stridulation area tri-angle shaped flat on same level as pronotal disc. Stridulatory file evenly tapering in dent size. Alae surpassing tegmina, in this area of same dark green shiny colour; with acute tips. Femora ventrally with spines. Fore tibiae slightly inflated in area of tympana. Abdomen. Last abdominal tergite with straight posterior margin (Fig. 3G). Cerci stout and setose; tips scythe-shaped with long serrated ridge (Fig. 3G, H, I). Subgenital plate with very short lobes, styli slightly inflated (Fig. 3I).

Female. Similar as male in habitus and colour (Fig. 2D) but with broader tegmina. Stridulatory veins as in Fig. 6D. Ovipositor as in Fig. 7C, subgenital plate as in Fig. 9C.

Measurements (mm).

Females (n=3). Total length of body: 26-27; median length of pronotum: 6.3-6.5; length of hind femur: 25-26.6; length of tegmina: 48-49; width of tegmina: 16; ovipositor: 5.5-6.

Males (n=1): Total length of body: 31.5; median length of pronotum: 6.9; length of hind femur: 25; length of tegmina: 43. Width of tegmina: 13.4.

Etymology.

from Latin: furca = fork because of the forked male cerci.

Habitat.

Lowland wet forest.

Distribution.

At present only known from the Udzungwa Mountains, Tanzania.