Eurycorypha prasinata Stål, 1874

Heller, Klaus-Gerhard, Hemp, Claudia, Massa, Bruno, Rakotondranary, Jacques & Krištín, Anton, 2019, Notes on a small collection of phaneropterine bush-crickets (Insecta: Orthoptera: Tettigonioidea) from Central and Southern Madagascar with the description of two new species, Zootaxa 4563 (2), pp. 297-310 : 299-302

Eurycorypha prasinata Stål, 1874

( Fig. 3 , 4 )

MADAGASCAR: Anakao , savanna and bush, 5 m a. s. l., - 23.655606°S, 43.651012° E ; 25 iii 2015, leg. Anton Krištín, CH 8595, male.

The specimen (habitus Fig. 3 ) is considered to represent a male of E. prasinata , a species assumed to be endemic to Madagascar and the Comoros ( Massa 2017a, c).

Before the studies of Massa (2017a, c) only five specimens from four species of the genus Eurycorypha have been known from Madagascar, one male (identified as E. prasinata ; Brunner von Wattenwyl 1878), one unsexed specimen (identified as E. cereris ; Saussure 1899), and three females, the type specimens of E. prasinata Stål,1874 , E. brunneri Brancsik, 1893 , and E. brevipennis Karsch, 1889 . Massa (2017c) listed another four Malagasy specimens under E. prasinata , although they differ in size and proportions from the specimens described by Brunner von Wattenwyl (1878) and Stål (1874) (see Table 2). The measurements of the specimen at hand agree with Massa’s data.

According to the description in Massa (2017c), E. prasinata belongs to Eurycorypha species with males with elongate and narrow tegmina, an undifferentiated 10 th abdominal tergite and rather stout, slightly curved cerci that have sclerotized dents at their tips. Several Eurycorypha species show these characters and thus are distinguished with difficulty, especially when song and habitat are not known. E. varia from northern Tanzania and E. pseudovaria from the Usambara Mountains are a striking example how similar Eurycorypha species of this group sometimes are. Also E. conclusa , a species distributed from coastal to inland habitats in eastern Africa belongs to this group of morphological similar males. The specimens known from Madagascar differ in dimensions and wing shape. However, there is also a sexual dimorphism in these characters as well as a quite large intraspecific variation, at least in some species. So in all of the above named three African species the females have more roundish tegmina resulting in different length/width ratios ( Table 2). A huge variability is seen in E. conclusa from different localities. Female individuals from West Kilimanjaro had a ratio of tegminal length/width of 2.3 while individuals from the North Pare Mountains had a ratio of 3.3. Also the size varied considerably. The smallest female individual was collected in Kwamgumi Forest Reserve in the East Usambara Mountains, Tanzania, and measured 15 mm in tegmina length and 6.4 mm in width while the largest individual measured came from the North Pare Mountains, Tanzania, with 30.5 mm tegmina length and 9.15 width. Only since we recorded the song of Kwamgumi and Kilimanjaro males conspecifity was proved.

von Wattenwyl; all data for E. conclusa Hemp , unpublished, from Tanzania.

Taking such a variability into account, we concluded that all Malagasy specimens we studied might belong to one species, to E. prasinata . On the other hand, different Eurycorypha species can morphologically be very similar. So only the detailed study of the songs and the different habitat made it possible to delimitate E. varia from E. pseudovaria (see Hemp 2017). The morphological similarity of these Eurycorypha species was also the base to erroneously assume a wide distribution of E. varia , a species very likely restricted to the montane zone of African Mts Meru and Kilimanjaro and some Eastern Arc Mountain Ranges while records of E. varia from the Usambara Mountains refer to E. pseudovaria . Madagascar may harbour more than one Eurycorypha species, but at present we do not know characters to separate them reliably.

This is also true for E. cereris and E. prasinata . Both are morphologically similar having an undifferentiated 10 th abdominal tergite and rather stout cerci armed with sclerotized dents, similar to E. varia and E. pseudovaria . E. cereris was described on a male by Stål (1857) from the Cape Region of South Africa while later ( Stål 1874) he described E. prasinata on a female from Madagascar without providing an exact locality. The male of E. prasinata was described by Brunner von Wattenwyl (1878). He wrote that he was not able to delimitate another male from Port Natal ( South Africa) from this species. Thus he listed this male from South Africa with a question mark. Since this publication South Africa is included in the known distribution of E. prasinata . Karsch (1889) listed E. prasinata from the Cape Region, West Africa (Accra; Ghana), Delagobai (today Maputo Bay, Mozambique), Mombasa ( Kenya), Bondei & Usambara ( Tanzania) and Anjoani (today Anjouan, The Comoros). Saussure (1899) on the other hand listed E. cereris from Madagascar (Nosy Bé). Very likely E. prasinata and E. cereris were partly misidentified and mixed up since females of these two species are very difficult to distinguish and males are also very similar in their outer genital morphology ( Fig. 4 ). Since most Eurycorypha species are highly endemic and restricted to certain areas it is very unlikely that E. prasinata occurs apart from Madagascar in wide parts of mainland Africa (see also Massa 2017c). The records of E. prasinata from Mombasa and the Usambara Mountains could belong to E. pseudovaria while the records from South Africa very likely belong to E. cereris . So we here suggest that E. cereris is restricted to Africa and E. prasinata to Madagascar.

Only the detailed study of this complex of morphologically very similar Eurycorypha species including song, habitat and genetics will shed more light on the distribution and the evolution of this group.

Further remark: In the collection of the Natural History Museum London, UK, specimens collected from Madagascar (data unpublished) are united under E. prasinata with the remark that E. brevipennis and E. brunneri are possibly synonymous with E. prasinata ( Ragge 1980) . However, E. brevipennis has very rounded and short tegmina and it is very improbable that it is synonym of E. prasinata .

Habitat. The specimen was found in coastal semiopen Euphorbia stenoclada bush, with some endemic Aloe

( A. divaricata , A. vaombe ), and introduced Euphorbia pulcherrima and Agave sisalana .

Figures

FIGURE 3. Eurycorypha prasinata, male, habitus; Anakao, 13 March 2015.

FIGURE 4. Genital structures of Eurycorypha species. A, B Eurycorypha cereris type (Museum Stockholm), apex dorsal (A) and subgenital plate (B), C, D male of E. prasinata from Madagascar from the collection of Natural History Museum London, UK, apex semi-dorsal (C) and subgenital plate (D), E, F specimen CH8595 from Anakao, apex semilateral (E) and subgenital plate (F).