Plangia geroi, Massa, 2022

Massa, Bruno, 2022, New and less known Orthoptera from biodiversity hotspots of Mozambique and Zambia (Tettigoniidae; Acrididae), Fragmenta entomologica 54 (1), pp. 27-44 : 39

Plangia geroi new species

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Material examined. Zambia: Lakeview Lodge , Sinazongwe (493m), MV Light Trap 23-28.II.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (1♂ holotypus, 4♂ paratypi in ANHRT, 1♀ paratypus in BMPC) ; Zambia: Lakeview Lodge , Sinazongwe (493m), Lepiled Light Trap 23-28.II.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (1♂ paratypus in BMPC) ; Zambia: Redcliff Zambezi Lodge , Luangwa, Lepiled Light Trap 11-17.III.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (2♂, 1♀ paratypi in ANHRT) ; Zambia: Gwabi River Lodge, Chirundu, Actinic Light Trap 8-11.III.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (1♂ paratypus in ANHRT, 1♂ paratypus in BMPC) ; Zambia: Gwabi River Lodge, Chirundu, MV Light Trap 8-11.III.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (1♂, 1♀ paratypi in ANHRT) ; Zambia: Gwabi River Lodge, Chirundu, Lepiled Light Trap 8-11.III.2019, V . Dérozier, M. Imakando, W. Miles, L. Mulvaney (4♂ paratypi in ANHRT, 1♂ paratypus in BMPC) ; Zambia: Mayukuyuku , Kafie NP, 21-26. XI.2013, Light trap, D. Oram, L. Smith, H. Takano (1♀ paratypus in ANHRT) .

Measurements (in mm). Males. Body length: 21.8- 25.0; length of pronotum: 5.5-5.9; height of pronotum: 5.4-5.7; length of hind femora: 14.8-16.8; length of tegmina: 32.5-35.1. Females. Body length: 22.8-25.3; length of pronotum: 5.8-5.9; height of pronotum: 5.6-5.7; length of hind femora: 15.7-17.4; length of tegmina: 33.0-35.7; length of ovipositor: 6.1-6.2.

Diagnosis. P. geroi n. sp. is a large species of Plangia , lacking of the black spot on the left tegmen and characterized by thin, incurved and pointed cerci.

Description. Male ( Fig. 13a ). Colour. Yellow-green, tibiae brown with blackish stripes, hind tibiae with black-tipped spines. Head and antennae. Fastigium of vertex as wide as scapus, not contiguous with the fastigium of frons. Face smooth. Thorax and legs. Anterior margin of pronotum concave, posterior margin rounded. Fore coxae armed with a spine. Fore femora short and compressed, with 3 spines on the inner ventral margin, fore tibiae a little compressed at the base, with open tympana, sulcate above, with 2 outer and inner ventral spines + 1 apical spur on each side, and 1 outer dorsal spur. Mid femora with 3 spines on outer ventral margin, mid tibiae with 3 outer and inner ventral spines + 1 apical spur on each side and 1 inner dorsal spur. Hind femora just compressed, with 4 spines on outer ventral margin, hind tibiae with 12 outer and inner dorsal spines and 9 outer and inner ventral spines + 3 apical spurs on each side. Wings. Tegmina 3.3 times longer than wide, with fore and hind margins more or less parallel, the fore margin only apically rounded. Stridulatory area of the left tegmen just raised, mirror on the right tegmen triangular ( Fig. 13e ); stridulatory file under the left tegmen arched and consisting of ca. 100 teeth evenly spaced ( Fig. 13d ). Abdomen. Cerci stout, pointed, in-curved and black-tipped ( Fig. 13c ); subgenital plate triangular, styli very small ( Fig. 13f ).

Female ( Fig. 13b ). Same characters as the male, length/ width tegmina 3.3, ovipositor short, gently up-curved, with many small teeth dorsally and a few apical teeth ventrally. Subgenital plate triangular and pointed ( Figs 13g, 13h ).

Etymology. Plangia geroi n. sp. is dedicated to Calogero Piazza (nickname ‘Gero’), excellent sports doctor and a very good friend.

Affinities. Among the African species of Plangia without a black spot on the left tegmen the following have cerci shaped as in P. geroi n. sp.: P. astylata Massa 2021 , which, however, has a much smaller size than P. geroi n. sp. and lacks of styli; P. graminea (Serville, 1838) has cerci pointed, but they are stouter than those of P. geroi n. sp. ( Hemp et al. 2015). We do not know the male of P. villiersi Chopard, 1954 (described from the female sex); however, the female of P. villiersi has more oval tegmina ( Chopard 1954) than the female of P. geroi n. sp. Additionally, P. geroi n. sp. has been compared with the following species of Plangia with a black spot on the left tegmen: P. satiscaerulea Hemp, 2015 (see above) has quite similar cerci, but the stridulatory file has only 68-74 teeth, while in P. geroi n. sp. teeth are ca. 100; P. unimaculata Chopard, 1955 (from South Africa), characterized by an evident round black spot on the left and right tegmina (Chopard 1955), has cerci stout and incurved, not pointed, as in P. geroi n. sp. Finally, P. amaniensis Hemp, 2017 has long, decussate cerci and P. variacantans Hemp, 2017 has unusually long styli.

Discussion. Plangia is a widespread genus, whose species are very difficult to distinguish between them, and for this reason the number of existing sibling species has been underestimated. Only recently researches carried out in east and southern Africa by Claudia Hemp ( Hemp et al. 2015, Hemp 2017) have shown that undescribed taxa live in those countries. Thus, the genus Plangia is richer in species than it is generally believed. Presently, three species are endemic to Madagascar, namely P. segonoides (Butler, 1878) , P. guttatipennis Karsch, 1889 and P. ovalifolia Bolívar, 1912 . Hemp et al. (2015) and Hemp (2017) have revised the P. graminea complex in East and southern Africa, finding that P. graminea (Serville, 1838) is very probably only distributed in southern Africa, while four previously unknown species are present in Tanzania: P. satiscaerulea Hemp, 2015 (Mt. Kilimanjaro), now found in Zambia, P. multimaculata Hemp, 2015 (Mt. Kilimanjaro), P. amaniensis Hemp, 2017 (Usambara Mts.) and P. variacantans Hemp, 2017 (Uluguru Mts.). Material collected in central and west tropical Africa allowed to highlight the high species diversity in the genus Plangia also in those forests, where Massa (2021b) described P. astylata , P. chopardi , and the male of P. karschi Chopard, 1954 . Only the female of P. villiersi Chopard, 1954 ( Guinea, Côte d’Ivoire and Gabon) is currently known. From central and west tropical Africa P. nebulosa Karsch, 1890 and the small P. deminuta Griffini, 1908 are also known. Finally, P. unimaculata Chopard, 1955 has been described from South Africa (only the holotype male is known). Including P. geroi n. sp., presently the number of species amounts to sixteen species.

Figures

Fig. 13 – Plangia geroi n. sp.: a, habitus of the male; b, habitus of the female; c, dorsal view of cerci and subgenital plate; d, stridulatory file under the left tegmen; e, stridulatory area on the left tegmen and mirror on the right tegmen; f, ventral view of the subgenital plate; g, ventral view of the subgenital plate and ovipositor; h, lateral view of the ovipositor.