Arantia (Euarantia) rectifolia Brunner von Wattenwyl, 1878

Massa, Bruno, 2023, Biodiversity hotspot in the Sangha Trinational Protected Area revealed through Orthoptera Tettigoniidae, Zootaxa 5331 (1), pp. 1-67 : 23-24

Arantia (Euarantia) rectifolia Brunner von Wattenwyl, 1878 and Arantia (Arantia) marginata Massa,

2021 ( Figs. 15a–15i)

Arantia rectifolia Brunner von Wattenwyl, 1878 , Monographie der Phaneropteriden 137; type locality: Bioko, Fernando Poo; depository: NMW, Vienna (♁ holotypus).

Arantia marginata Massa, 2021 , Ann. Soc. ent. Fr. 57(1): 59; type locality: Gabon, Mts. de Cristal ; depository:ANHRT, Hereford (♁ holotypus).

Material examined of A. marginata . Republic of Congo, Sangha prov. , N-N NP, Ndoki formation camp (secondary forest) (356m) 02°12’48.5”N, 16°23’45.6”E, 23. VI.2022, MV Light Trap , V . Dérozier (1♁) ; Republic of Congo, Sangha prov. , N-N NP, Bomassa camp (secondary forest) (353m), 02°12’36.9”N, 16°11’30.2”E, 18. VI –3.VII.2022, MV Light Trap , V . Dérozier (1♁) ; Republic of Congo, Sangha prov. , N-N NP, Bomassa camp (secondary for.) 02°12’36.9”N, 16°11’30.2”E, 16–23.IX.2022, MV Light Trap , V . Dérozier, B. Fouka, A. Kirk-Spriggs, H. Takano (7♁); Republic of Congo, Sangha prov. , N-N NP, Makao camp (secondary for.) 02°35’42.2”N, 17°10’08.3”E, 23–29.IX.2022, MV Light Trap , V . Dérozier, B. Fouka, A. Kirk-Spriggs, H. Takano (1♁); Republic of Congo, Sangha prov. , N-N NP, Ndoki formation (secondary forest), 02°12’47.7”N, 16°23’45.8”E, 29.IX–1.X.2022, MV Light Trap , V . Dérozier, B. Fouka, A. Kirk-Spriggs, H. Takano (1♁); Republic of Congo, Sangha prov. , N-N NP, Mbeli camp ( Gilbertiodendron forest) (341m) 02°14’23.8”N, 16°23’52.1”E, 1–10.X.2022, MV light trap, V. Dérozier, B. Fouka, A. Kirk-Spriggs, H. Takano (5♁); Republic of Congo, Sangha prov. , N-N NP, Bomassa camp (secondary forest) (341m) 10–16.X.2022, MV light trap, V. Dérozier, B. Fouka, A. Kirk-Spriggs, H. Takano (4♁); Republic of Congo, Sangha prov. , N-N NP, Mombongo camp 02°10’30.7”N, 16°8’37.7”E (352m) 2–7.II.2023, MV light trap, N.M. Bakala, V . Dérozier, A. Kirk-Spriggs, G. László (1♁); Republic of Congo, Sangha prov. , N-N NP, Mbeli camp (372m) 14–20.II.2023, MV light trap, N.M. Bakala, V . Dérozier, A. Kirk-Spriggs, G. László (1♁); Republic of Congo, Sangha prov. , N-N NP, Mondika camp 02°21’50.63”N, 16°15’25.82”E, 7–14.II.2023, MV light trap, N.M. Bakala, V . Dérozier, A. Kirk-Spriggs, G. László (8♁); Republic of Congo, Sangha prov. , N-N NP, Bomassa Camp (341m), 6–14. V.2023, MV light trap, V. Dérozier, A. Kirk-Spriggs, G. László, S. Mvouende (3♁, one with spermatophore); Republic of Congo, Sangha prov. , N-N NP, Makao camp 15–21. V.2023, MV Light Trap , V . Dérozier, A. Kirk-Spriggs, G. László, S. Mvouende (2♁); Republic of Congo, Sangha prov. , N-N NP, Mondika camp 02°21’50.63”N, 16°15’25.82”E, 27.IV–6. V.2023, MV light trap, V. Dérozier , A. Kirk-Spriggs, G. László, S. Mvouende (6♁, 1♀) ( ANHRT) .

Distribution. Arantia marginata was previously known from Gabon, Central African Republic, Côte d’Ivoire, Liberia, Guinea, here recorded also from Republic of Congo.

Remarks. The subgenus Euarantia was established by Heller et al. (2014) on the base of the width of the tegmina being greater than 12 mm and the hind tibiae curved; however, A. rectifolia Brunner von Wattenwyl, 1878 , considered to belong to the subgenus Euarantia , has the hind tibiae curved but the width of the tegmina is variable in size, sometimes being shorter than 12 mm, often mixing with A. marginata Massa, 2021 (belonging to the subgenus Arantia ) from which the morphological separation may be difficult (however, the shape of male cerci and stridulatory file allow for the distinction). In the group of A. rectifolia morphological differences generally are small, but the shape of the stridulatory file and the number of teeth, as well as the male cerci tip, allowed Hemp & Massa (2017) to describe Arantia tanzanica (ca. 80–85 teeth; Figs. 15a, 15b), found in Zimbabwe, Mozambique, South Africa, Swaziland and Zambia ( Massa 2022a). Massa (2021b) highlighted the difficulty in identifying Arantia rectifolia from A. marginata and a possible third species which is sometimes mixed between them, recognizable only by its stridulatory file (ca. 85 teeth, like in A. tanzanica while in A. marginata there are ca. 65 teeth, and in A. rectifolia ca. 45–50).

Fig. 15 reports five stridulatory files and cerci of the respective specimens from Tanzania ( Arantia tanzanica ) ( Figs. 15a, 15b), Côte d’Ivoire ( Arantia aff. tanzanica ) ( Figs. 15c, 15d), Gabon ( Arantia marginata ) ( Figs. 15e, 15f), Central African Republic ( Arantia rectifolia ) ( Figs. 15g, 15h) and Côte d’Ivoire ( Arantia aff. rectifolia ) ( Figs. 15k, 15i; this specimen, due to the width of the tegmina being shorter than 12 mm was considered as being Arantia aff. marginata by Massa 2021b). It is possible that the specimens of Figs. 15g, 15h, 15k, 15i represent two species belonging to the rectifolia -group. A biomolecular analysis probably could answer this question, but the actual knowledge of taxonomy of this group of Arantia allows A. rectifolia , as well as A. tanzanica , to be moved from the subgenus Euarantia Heller, 2014 to the subgenus Arantia Stål, 1874 ; thus, their nomenclature should be changed as follows: Arantia (Arantia) rectifolia Brunner von Wattenwyl, 1878 , and Arantia (Arantia) tanzanica Hemp & Massa, 2017 .