Neoperla costata Zwick & Zwick 2023, n. sp.
Creators: name: Zwick, Peter
name: Zwick, Andreas
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Perlidae
Neoperla
Neoperla costata

description: 4. Neoperla costata n. sp.    
(Figs. 11–12, 17, 22–24)  
 Type material studied: ♀ holotype, Republic of Guinea, Riv. Rokel à Badala, 11.8.1989 (PZ, gift Élouard, 16/87, NEOP006). Paratypes: 3♀, Togolese Republic, Mono R., Tététou 25.11.1985 V. Landa (PZ, slides Z20.17–20.19). 4 ♁, 3♀, 22mls SE Tapeta [6.49, -8.86], 17.8.1966, Ross & Lorenzen (CASENT 8413046 & PZ, slides Z20.5–6, Z20.21-25).   
 Additional material studied: Republic of Cameroon: 2♀: Adamaua [9.255, 13.413] Poli (500m) b. Garua A. Weidholz 1.X.36 (Slides Z 20.02 + 03; NHMW). République de Côte d’Ivoire: 1♁, Côte d’Ivoire, Kouibly [Kuibli, 7.17°N, 722°W, 288m] déd. 1938 \ Museum Paris 1938 – 39 L. Chopard; 1♀, Côte d’Ivoire, Daloa [6.45°N, 6.87°W], 12.1930 –4.1931, Ch.Alluaud & P.A.Chappuis (MNHN Paris 13; egg slide also PZ). Republic of Liberia: 1♁, 1♀, Liberia, 36 mi S Voinjama [8.42, -9.75], 13.8.66, Ross & Lorenzen (CAS Slide ♀ Z20.14). 1 J, Liberia, Suakoku, 31.1.52 Blickenstaff (USNM). Republic of Sierra Leone: 1♀, Njala [12.02°N, 8.23°W] i-IX-29 E.Hargreaves Pres. by Com. Ent. BM 1951-120 (BMNH; egg slide also PZ). United Republic of Tanzania: 1♀, 25. Dec. 1987. Tanzania: Kimboza Forest, near Morogoro [-6.82100, 37.66100]: lowland rain forest (Slide Z 19.72, HNHM). Togolese Republic: 1♀, Togo, R. Mono, Ngonlutu, 29.11.1985 V. Landa (Z16.121); 1♀, Togo, R. Mono, 01.12.1985, V. Landa (Z16.122); 1♀, Togo, Tététou (Mono R.), 25.11.1985, V. Landa (Z16.116).   
 Habitus. WL 8.5–10.0mm in males, 11.0– 11.5mm in most females, 20mm in the Tanzanian female. SSt with 3 branches. Ochre coloured, no recognisable pattern, probably faded.   
 Male (Figs. 11–12). T7 with faint indications of a fore-field of the caudal process which is a flat blunt-tipped triangle, in 2 specimens a little uplifted. Mediobasal callus of HT10 plump, the process short, straight, blunt-tipped (Fig. 11). Caudal margin of S8 without setal fringe. Remainder as for the group.   
Penis a wide plump tube which is distally curved, the ventral side shorter than the dorsal side (Fig. 12) where a protruding bare bulb displaces the endophallus base a little to the ventral side. The endophallus immediately curves back to the dorsal side, resembling a thick curved sausage with sparse slender spines. At the endophallus base small sharp spines form an oblique band. The nipple-shaped bare apex with the gonopore is surrounded by a dense ring of small spines. No recurrent tube seen.  
 Female (Fig. 17). External characters as described above for the group. Vagina slender, without armature. SSt longer than vagina, flat, wide and curved, distal part longer than the forward-directed base.A narrow strip with small pale triangular teeth along most of convex edge. Remainder of stalk only longitudinally wrinkled, base very wide. End wide, blunt, the short narrow duct supports a long coiled spermatheca.   
 Egg (Figs. 22–24). 425*210µm, eggs of females from Adamaua 426*188µm, on average 2.3 times longer than wide. In side view, the sides are slightly convex, base of operculum wider than base of collar. Operculum a cone with concave flanks, punctation exceedingly fine, unordered. Where the 12 ridges end a projecting shoulder appears in side view. Egg cross sections resemble a cogwheel, with sharp keels (Fig. 22). Keels are connected to 2 rings of cells with raised walls on the sessile collar. Anchor cavity deep, anchor mushroom-like. Punctures between ridges in groups of 3–4 transverse rows, bare strips separating groups of rows continue to top of ridges and are in side view visible as small denticles.   
 DNA (Figs 491–493). Only the female holotype from Guinea was sequenced with the genome skimming approach and is strongly supported (87.4/100/100) as sister to N. rostrata n. sp..   
 Notes. DNA data suggested the distinction of N. costata from N. serrula (see below). However, we know several additional different-looking females from various sites which we cannot identify. Future studies of more material, especially also males, are desirable.   
 Etymology. The name costata (Latin, with ribs) is an adjective in female gender referring to the sharp egg ridges.
description: Published as part of Zwick, Peter & Zwick, Andreas, 2023, Revision of the African Neoperla Needham, 1905 (Plecoptera: Perlidae: Perlinae) based on morphological and molecular data, pp. 1-194 in Zootaxa 5316 (1) on pages 29-31, DOI: 10.11646/zootaxa.5316.1.1, http://zenodo.org/record/8154005