Gonatoxia helleri 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 : 278-279

Gonatoxia helleri C. Hemp sp. n.

Holotype male.

Tanzania, Uluguru Mountains, Morogoro District, forest above Morningside, February 2016. Depository MfN.

Paratype female, same data as holotype; depository MfN.

Further paratypes.

All Tanzania; 13 males, 17 females, same data as holotype, March and April 2016; 3 males, 1 female, East Usambara Mountains, Nilo forest reserve, February and May 2016; 1 male, East Usambara Mountains, Sigi Trail, lowland wet forest, 450 m, November 2015; 1 male, 4 females, West Usambara Mountains, Lutindi Mental Hospital, submontane forest, 1250 m, February 2015 and June 2016; 1, male, 1 female, West Usambara Mountains, Mazumbai forest reserve, 1600 m, March 2016; 7 males, 3 females, Udzungwa Mountains National Park, Mangula Gate, lowland wet forest, 300 m, March, July, September 2015, January, March and May 2016; 1 female, Kisarawe District, Kazimzumbwi Forest Reserve, February 2015 (collection C. Hemp).

Further material studied.

1 male, Kenya?, Kibatuga, 20/10/51, B.M 1966-628; 1 female, East Africa 82/24, Tanzania, Korogwe-Msata Road, 103 km north of Msata, summit of kopj, 21 IX 1982, coll. N. Jago; 1 female, Tanzania, Kilosa. 10 IX 1926, coll. N. C. E. Miller, B.M. 1928-281; 1 female, Tanzania 63, B.M. 1950-96; 1 female, Tanzania, Lindi, Ndanda, 300 m, 5. III 1952, coll. Lindemann and Pavlitzki; 1 male, N Derema, coll. G. v. Son, B.M. 1969-331 (depository: NHML). The specimens from the collection of the NHML are not listed as paratypes since they were either females that are difficult to identify without males or males where the stridulatory file could not be studied.

Diagnosis.

Gonatoxia helleri sp. n. is very similar to Gonatoxia maculata . Both species have about the same size and colour and shape of tegmina and wings. However, Gonatoxia helleri sp. n. usually have far less conspicuous maculae on the tegmina, being smaller and more longish and fewer in number. Mostly these maculae start about where the Rs vein branches off. Typical is also a dense net of white veins, especially in the costal area of the tegmen forming multiple small white dots. Also the costal margin is bordered white with veins branching off thick and very white in both sexes when alive (weakly expressed in the Udzungwa population of Gonatoxia helleri sp. n.). The males of Gonatoxia helleri sp. n. can also be distinguished from Gonatoxia maculata by in the male cerci wearing a smaller sclerotized ridge or 1-4 single teeth clustered tightly together whereas Gonatoxia maculata males wear a stouter and larger serrated ridge at the tips of the male cerci. Differences are also seen in the stridulatory file of the males. The stridulatory file of Gonatoxia maculata evenly tapers in dent size from one side to the other (Fig. 4A) while in Gonatoxia helleri sp. n. the stridulatory file is somewhat constricted and elevated midway with larger teeth following running to the margin of the left tegmen (Fig. 18; Fig. 4C, arrow) and thus dividing the whole structure into three parts. Gonatoxia helleri sp. n. has a male subgenital plate which is not as deeply incised as in Gonatoxia maculata and the styli are flattened and broad (Fig. 17C) while in Gonatoxia maculata the subgenital plate is deeper incised and the cerci longer and more stout (Fig. 3C). Gonatoxia immaculata and Gonatoxia furcata sp. n. both are shiny dark green usually, Gonatoxia immaculata males often have conspicuous white to orange patches on the tegmina. The cerci of male Gonatoxia immaculata have a sclerotized curved ridge at their tips while Gonatoxia furcata sp. n. males have scythe-shaped cerci. The females are often difficult to identify since also more light green individuals of Gonatoxia immaculata occur and the shiny colour vanishes in preserved specimens. Further Gonatoxia helleri sp. n. was found syntopically with Gonatoxia immaculata in the East Usambara Mountains. In the Udzungwa Mountains Gonatoxia helleri sp. n. occurs syntopically with Gonatoxia furcata sp. n. However, Gonatoxia furcata sp. n. females are generally larger than Gonatoxia helleri sp. n. females and of shiny dark green colour. Gonatoxia immaculata females are difficult to distinguish from Gonatoxia helleri sp. n. females and only the study of larger series comparing the bowl-like structure laterally on the ovipositor may help to identify females of both species, especially in preserved specimens.

Description.

Male. General habitus and colour. Predominantly green with oval tegmina and 2-4 small ivory patches on tegmina (Fig. 16A). Whitish dots also on pronotum and legs. Pair of white lines often present starting in upper part of compound eye and running over head and pronotum. As in all Gonatoxia species abdominal tergite bright yellow, tarsi whitish. Head and antennae. Antennae thin and whitish, surpassing tegmina. Eyes round, except for whitish upper part green or light green. Thorax and wings. Pronotal disc flat, longer posteriorly than pronotal lobes which are evenly rounded at lower part, with acute edge at insertion of tegmina and wings. Tegmina broad with leaf-like pattern of the veins, slightly truncate at tips, alae surpassing tegmina. Alae hyaline except for tips which are of same green colour than tegmina. Tegmina with net of white veins, on veins often white dots are formed, especially in costal area (Fig. 15B). Costal margin white bordered with veins directly branching off at margin thick and white. Stridulatory file (Fig. 17D) separated into three parts with small teeth near tegmen base, an elevation midway (arrow Fig. 4C) and large teeth at outer part of file. Legs. Fore femora with one outer spine and 1-4 inner spines ventrally. Mid femora with 3 outer and no inner ventral spines. Hind femora with double row of irregular set of 7-8 ventral spines. Fore tibiae in area of tympana slightly enlarged, with conchate inner tympanum and open oval tympanum on outer side; midway dorsal one spine, ventral several irregular set spinules. Mid tibiae with irregular set spinules in four rows. Hind tibiae dorsally two ridges densely covered by small spines, ventral side with few irregular set spines, curved. Abdomen. Venter white. Cerci slender and incurved (Fig. 17A, B), at tips with short ridge or 1-4 single sclerotized dents. Subgenital plate medially u-shaped incised, styli flat, roundish and somewhat inflated, touching each other medially when insect is alive (Fig. 17C).

Female. Similar to male in size but with more roundish tegmina and mostly without ivory patches on tegmina or 1-2 and very small ones, mostly where Rs branches off. Also with for this species typical costal margin bordered white with branching off veins thicker and white and net of white veins forming white dots. Stridulatory veins as in Fig. 6C. Ovipositor up-curved, serrated at tip (Fig. 7D). Bowl-like structure formed laterally on base of ovipositor as in Fig. 8B. Subgenital plate tri-angular (Fig. 9C).

Body mass.

(mg; n=1) Male 990. Female 1462 (culture-reared, 01.08.2015).

Measurements (mm).

Females (n=6): Total length of body: 25.8-27.5; median length of pronotum: 6.5-6.8; length of hind femur: 26.5-28.6; length of tegmina: 44.0-45.9; width of tegmina: 14.8-14.4; ovipositor: 5.2-5.4.

Males (n=6): Total length of body: 23.5-26.4; median length of pronotum: 5.7-6.5; length of hind femur: 25-28; length of tegmina: 42.5-44.4; width of tegmina: 12.5-13.4.

Etymology.

Named after Klaus-Gerhard Heller.

Habitat.

Lowland wet to submontane forest.

Distribution.

Tanzania and very likely Kenya.