Spotted males, uniform females and the lowest chromosome number in Tettigoniids recorded: Review of the genus Gonatoxia Karsch (Orthoptera, Phaneropterinae)
Author
Hemp, Claudia
Author
Heller, Klaus-Gerhard
Author
Warchalowska-Śliwa, Elzbieta
Author
Hemp, Andreas
text
Deutsche Entomologische Zeitschrift
2016
63
2
271
286
http://dx.doi.org/10.3897/dez.63.10799
journal article
http://dx.doi.org/10.3897/dez.63.10799
1860-1324-2-271
3F2DB40D1E9140619323983DAC0D862B
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.
Figure 17. Morphological details of male
Gonatoxia helleri
sp. n. A. Semilateral view on abdominal apex. Scale bar 1 mm B. Dorsal view on abdominal apex with sclerotized ridge of cercus. Scale bar 1 mm C. Subgenital plate. Scale bar 1 mm D. Stridulatory file. Scale bar 500
µm
.
Figure 18. Detail of stridulatory file of
Gonatoxia immaculata
with teeth directed towards the anal end.
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.