Neoperla costata, Zwick & Zwick, 2023

Zwick, Peter & Zwick, Andreas, 2023, Revision of the African Neoperla Needham, 1905 (Plecoptera: Perlidae: Perlinae) based on morphological and molecular data, Zootaxa 5316 (1), pp. 1-194 : 29-31

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.

Figures

FIGURE 491. Codon-model maximum likelihood phylogram based on 83 largely complete mitochondrial genome sequences only (mt-NT). Statistical support values (SH-aLRT, UFBoot) from this and other analyses summarised by squares as explained in the figure. Terminal labels include information on the species, type status, gender, originating country, unique sequence identifier (NEOP###), sequencing approach and total basepairs of 13 mitochondrial, protein-coding genes. Clades of particular interest highlighted with colours that correspond to the clades in other trees. HT = holotype; PT = paratype; PCR = Polymerase Chaine Reaction; WGS = Whole Genome Shotgun.

FIGURE 492. Simplified overview of codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). Terminal labels include information on the species only. Clades of particular interest highlighted with colours that correspond to the clades in other trees. The full tree is shown in Figs 493-498.

FIGURE 493. Partial (outgroup, clades A, B, D) codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). Statistical support values above branches or near nodes are SH-aLRT and UFBoot for the codon-model analyses, followed by NT123 UFBoot. Terminal labels include information on the species, type status, gender, originating country, unique sequence identifier (NEOP###), sequencing approach and total basepairs of 13 mitochondrial, protein-coding genes. Clades of particular interest highlighted with colours that correspond to the clades in other trees. See Fig. 492 for an overview. HT = holotype; PT = paratype; PCR = Polymerase Chaine Reaction; WGS = Whole Genome Shotgun.

FIGURES 11–15. Males in the N. lujana-complex. N. costata n. sp.: 11, male tergites 7–10, dorsal view; 12, artificially everted penis. N. lujana Navás, artificially everted penes: 13, from Cameroon, Etambo R.; 14, from Bayanga (CAR). 15, N. serrula paratype from Ghana (NEOP009).

FIGURES 16–17. Female genital situs: 16, N. lujana Navás, not to scale; 17, N. costata n. sp. (Liberia, near Tapeta). co, common oviduct; scl, sclerite in vagina; sd, spermathecal duct; SSt, spermathecal stalk; V, vagina.

FIGURES 18–25. eggs of the N. lujana-complex: 18, the N. lujana Navás holotype; 19, from Bayanga (CAR, NEOP019); 20, from Odzala N. P. (NEOP018); 21, top view of egg (D. R. Congo, N of Bukavu) (after Moore 1991). N. costata n. sp.: 22, optical cross section; 23, lateral view of an egg, with enlarged profile of a ridge (Liberia, near Tapeta) to the left hand side; 24, egg from Adamaua. N. serrula n. sp.: 25, egg, an enlarged profile of a ridge (Holotype, NEOP010, Ghana, Agumatsa falls, slide 20.12) to the right hand side. Scales are 100µm, unless differently indicated. Details of costae are to the same scale.