Apteroscirtus densissimus Hemp 2020, n. sp.
Creators: name: Hemp, Claudia
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Phaneropteridae
Apteroscirtus
Apteroscirtus densissimus

description: Apteroscirtus densissimus n. sp.   
(Fig. 1–6)  
Holotype male. Tanzania, Nguru Mountains, submontane forest, March 2017, collected between 6°03´12.1´´S 37°33´38.7´´ E and 6°04´01.3´´ S 37°34´24.2´´ E. Depository: CCH. 1 male, 8 females, same data as holotype and February and June 2017, March 2019 and March 2020. Depository: CCH.  
 Description. General body shape and colour: stout body, mottled brown to black (Fig. 1 A, B). Head and antennae.—Antennae about twice the body length, about 5.5 cm long. Fastigium verticis with median indentation forming two small „horns“ when seen laterally or from the front (Fig. 4 A). Fastigium verticis abruptly forming acute angle to face merging into frons of face without clear separation. Thorax.—Pronotum cylindrical and hardly constricted at first sulcus; disc of pronotum evenly rounded, rugose, of uniform colour. Tegmina not discernible. Legs.—Legs long and slender, base of hind femur stout. Hind femora surpassing apex of body about body length, hind tibiae as long as femora. Tympana of fore tibiae oval and open on both sides. Fore femora on inner side with 2–4 four stout short spines (different number of spines even on the same specimen), outer side unarmed; mid femora unarmed. Hind femora at apical third ventral double row of irregular set spines. Abdomen.—Abdominal tergites medially with smooth wart-like elongate structures, giving males a serrated appearance when seen laterally (Fig. 1 A, B). Cerci stout, rounded and short (Fig. 4 B). Subgenital plate a typical fork, rather stout and short (Fig. 4 B, C); without styli.   
Female. Larger than male. No signs of tegmina, as male apterous. Legs and spination as in male. Pronotum broad with sulci hardly constricting pro-, meso- and metazona and thus almost evenly rounded (Fig. 5 A). Dorsum of abdomen as in male, medially with large darker coloured knobs. Ovipositor stout and slightly up-curved at posterior part (Fig. 1 C, D). Subgenital plate a broad shield (Fig. 6 A).  
Measurements, males (mm) (N = 2). Body length 23.2–26. Length of pronotum 6.7–7.0. Length of hind femur 26–27.5.  
Measurements, females (mm) (N = 5). Body length 28.6–33.5. Length of pronotum 7.4–8.0. Length of hind femur 28.3–31.1. Ovipositor length 17.5–18.7.  
 Diagnosis. Both males and females of A. densissimus n. sp. differ from the other East African species A. cristatus Hemp, 2013 and A. planidorsatus Hemp, 2013 in a having an unconstricted broad pronotum that is evenly rounded while the pronotum in both other species is markedly constricted at the first sulcus, especially in A. planidorsatus (compare Fig. 3 A, C, E and 5 A–C). When seen from above the fastigium verticis is medially incised both in male and female of A. densissimus n. sp., but has a rugose but more or less straight margin in A. cristatus and is smooth and slightly rounded in A. planidorsatus (Fig. 3 B, D, F). Both males of A. cristatus and A. planidorsatus have tiny elongated tegminal lobes while in A. densissimus n. sp. no remains of the tegmina were detected. Further A. densissimus n. sp. is larger and stouter than the other two species. The subgenital plates of female Apteroscirtus species do not provide good distinguishing characters. Both in A. densissimus n. sp. and A. cristatus the female subgenital plate is a broad shield while in A. planidorsatus the posterior margin is slightly incised (Fig. 6 A–C).   
 Habitat. A night-active species of the litter and on herbs in submontane to montane forest.   
 Distribution. Known at present only from the Nguru Mountains in Tanzania.   
 Etymology. From Latin - densissima, thick, stout since this new species is larger and stouter than the other two Tanzanian Apteroscirtus species.
description: Published as part of Hemp, Claudia, 2020, New species of Mecopodinae (Orthoptera, Tettigoniidae) from Tanzania, pp. 138-150 in Zootaxa 4790 (1) on pages 139-142, DOI: 10.11646/zootaxa.4790.1.8, http://zenodo.org/record/3887942