Heteropternis minuta Uvarov, 1934

Felix, Rob P. W. H. & Massa, Bruno, 2016, Orthoptera (Insecta: Tettigonioidea, Pyrgomorphoidea, Acridoidea) of Kafa Biosphere Reserve, Bale Mountains National Park and other areas of conservation interest in Ethiopia, Zootaxa 4189 (1), pp. 1-59 : 52-54

Heteropternis minuta Uvarov, 1934

http://lsid.speciesfile.org/urn:lsid: Orthoptera .speciesfile.org:TaxonName:67588 Figure 43–46

Material examined. ETHIOPIA: Let Marefià (Scioa=Shewa), XII.1878, Antinori (1Ƌ, MSNG) ; Let Marefià (Scioa), VIII.1887, Ragazzi, (1♀, MSNG) ; Mount Chillalo (10,000 ft.), 22.XI.1926, H. Scott (1Ƌ holotype, 2Ƌ paratype, 2♀ paratype, NHM) ; Jem-Jem Forest (> 8,000 ft.), 10.X.1926, H. Scott (1♀ paratype, NHM) ; Wooroomon , 1.IV.1904, C. Singer (1♀ paratype, NHM) ; SNNPR, Keffa, Bamboo Forest (2620 m), 20.IV.2015, R.P.W.H. Felix (7Ƌ, 10♀, RFPC) (1Ƌ sound recorded), B. Massa (1Ƌ, 4♀, BMPC) ; Keffa, Hana Wetland (2425 m), 19.IV.2015, R.P.W.H. Felix (1♀, RFPC) ; Oromia, Goba Forest, Bale Mountains N.P. (3130 m), 10.XII.2015, B. Massa (1♀) ( BMPC) ; Wollega, Didessa river (1280 m), 11.XI.2010, A. Sciarretta and M. Colacci (1♀).

Distribution. Endemic to Ethiopia.

Habitat. The habitat of our specimens collected in Kafa consisted of bare, stony patches of soil along a high altitude road ( Figure 3 c).

Sound. The song of one male specimen, collected at Bamboo Forest (2620 m) (nr. 2 in Figure 1 ), has been recorded, analysed and plotted into an oscillogram ( Figure 44 ). The calling song consists of a series of ticking sounds, produced by backwards kicking of one of the hind legs. Series last for about 10–30s and consists of about 15–20 (5–40) ticks. When close to each other, males do not show a special rivalry song. It is not known if a specialized courtship song is produced, when a male is close to a female (pers. comm. B. Odé).

A closely related species, Heteropternis couloniana , also produces a ticking sound created by the hind tibiae ( Hemp & Hemp 2003).

Remarks. Uvarov (1934) described H. minuta based on a collection of specimens collected at different localities and on different occasions in Ethiopia. The holotype was designated to a male from Mount Chillalo (Oromia, between Addis Ababa and Bale Mountains at 3050 m) ( Figure 45 ). Paratypes were designated to specimens from Jem-Jem Forest (60 km west of Addis Ababa) and Wooroomon (probably around Lake Turkana, in the southwestern corner of the country, since it was collected during the Lake Rudolf Expedition of 1904) ( Figure 46 ). Uvarov (1934) mentions the small size (“smaller than any known species”), the tegmina reaching the apex of the hind knees and the peculiarly coloured hind wings, as the main characteristics of the species. There are, however, some differences between the holotype and the paratypes. All specimens from the type locality (Mount Chillalo) have tegmina reaching the hind knees, while the paratypes from Jem-Jem Forest and Wooroomon have tegmina passing the hind knees ( Table 5 ). Our material from Kafa, as well as specimens in the NHML identified as minuta by Jago and Dirsh (not listed above), and one of the two specimens in the MSNG identified by Baccetti, also have tegmina reaching beyond the hind knees. This variation in length of the tegmina can possibly be attributed to altitudinal differences, or there is more than one taxon involved. Further study is required to determine the taxonomic status of the minuta- specimens outside the type locality. Uvarov (1934) mentions the paratype specimens from Jem-Jem (> 2400 m) and Wooroomon slightly smaller than the ones from the locality of the holotype (Mount Chillalo, 3050 m), but study of the material reveals the latter two are larger ( Table 5 ).

Heteropternis minuta is probably closely related to H. couloniana (Saussure, 1884) , which is also reported from Ethiopia by Jago (1977). The latter species has tegmina passing the hind knees much farther than in the longer-winged specimens of minuta , has dark spotting on the sides the abdominal segments so it looks like they are banded. H. couloniana has on average a much darker infumated apical half of the hindwing than minuta ( Figure 47 ) ( Table 6 ).

Figures

FIGURE 1. Study sites 2015 in and around Kafa Biosphere Reserve and Bale Mountains N. P., Ethiopia. The numbers correspond with those in Table 1.

FIGURE 3. Habitats at collecting sites. a: Komba Forest (1860 m); b: Hana Wetland (2425 m); c: Bamboo Forest (2620 m).

FIGURE 43. Heteropternis minuta; 1 – 3, 5: Bamboo Forest (2620 m), 4: Hana Wetland (2424 m), Ethiopia. 1 a & 1 b show the same male specimen. 4 a and 4 b show the same female specimen. Male specimen nr. 3 is sound recorded (Figure 44). Scale bar represents 1 cm.

FIGURE 44. Oscillogram of the song of a male Heteropternis minuta, Bamboo Forest (2620 m), Ethiopia. Recording and oscillogram by Baudewijn Odé, the Netherlands.

FIGURE 45. Holotype Ƌ of Heteropternis minuta, Mount Chillalo (3050 m), Ethiopia. Scale bar represents 1 cm.

FIGURE 46. Paratype ♀ of Heteropternis minuta, Wooroomon, Ethiopia. Scale bar represents 1 cm.

FIGURE 47. Heteropternis couloniana, holotype ♀ of synonym Heteropternis vittata Kirby, 1902, Zomba, British Central Africa (= Malawi). Scale bar represents 1 cm.