Neoperla vicina, 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 : 125-127

57. Neoperla vicina n. sp.

( Figs. 320–322 , 330–331 )

Type material: Democratic Republic of the Congo: ♀ holotype ( NEOP250 , CASENT 8413118 ) , 6♀ paratypes: Belg. Kongo, 39km S Walikale [-1.40, 28.00], 700m, 25.12.1957, Ross & Leech (Z19.29 NEOP249 , Z19.30 NEOP251 ,both CASENT 8413119; 1♀, same locality and date, slide Z.21.01 ( SMNS). 1 ♀ paratype, Kongo, Odzala Nat. Park [1.19°N, 14.85°E; 560m], 29.9.[1996]– 3.3.1997 leg. V.Sinaev ( MfNB).

Additional material studied: 1♁ (presumed): Teleki-exp. 1988 8 No. 332 \ 180 km W from Bukavu [-2.49, 28.84], rainforest, 16.5.1988 (slide 19.74; HNHM, Budapest) .

Habitus. WL of male 10.7mm, of female 11.2–12.3 mm. Light yellowish brown, no pattern, possibly faded. Wings slightly turbid, yellowish, antenna entirely, cercus distally brownish. Narrow black ocellar rings, in several specimens a light brown spot between the ocelli. Legs of male darker, hind tibia widened.

Male ( Figs. 320–322 : presumed). As for the complex. Middle of T7 caudally with a small dark plate-like area which appears caudally serrate because SB on its rear face are visible from above ( Fig. 320 ). The small plate hardly projects. T8 with strongly raised conical process ( Fig. 321 ). HT10 long, slender, slightly concave, tip blunt, a little downcurved, mediobasal callus tongue-shaped.

8 An informal designation of the Hungarian Scientific Africa Expedition 1988, made in memory of the expedition of count Samuel Teleki a hundred years earlier. Locality list in Vojnits (1990).

Penis tubular, soft, almost straight, undulating a little. Tube with a subterminal dorsal patch of low scales, tips point to penis base. Endophallus base straight, bare, curves ventrad only where the wide dense dorsal band of small conical spines begins and ends where the endophallus loop crosses the penis tube. Ventral spine band similar, shorter, a wide bare strip between bands. Terminal section of endophallus wide and bare ( Fig. 322 ).

Female ( Fig. 330 ). As for the complex. The caudal median sclerite on S8 is very small. Vagina unmodified, SSt about 1.5 rings long, the bare concave edge of the base is not very apparent. The completely scaly section thins distally, the scales form a gapless inner coat of the SSt.

Egg ( Fig. 331 ). Elongate, 400*195─295µm, with about 16 straight striae beginning at some distance from the anchor pole (arrow in Fig. 331 ) and ending before reaching the operculum. The egg is very slender, because of the strongly projecting costae the egg diameter in the striate section is larger than in the smooth sections. The collar is a low ring with projecting inner edge which constrains the opening of the funnel-shaped anchor cavity which has a pearly inner surface. The anchor is mushroom-shaped, with solid stem. Sulci with extremely fine and dense unordered punctation, micropyles are freely visible. All striae end at the same level at the operculum base but there is no mark or suture. The operculum is high and strongly raised, with nipple-like top, the punctation is dense, unordered, and even finer than in the sulci, no cells.

Variation. Contour of eggs varies, apparently with degree of hydration. The female from Odzala N.P. contained very few residual eggs which seemed to be smaller and less elongate than others.

DNA ( Figs. 491–492 , 497). The female holotype and two female paratypes from the D. R. Congo were sequenced with the genome-skimming approach, representing the limited geographic distribution of this species and providing very strong support (98.9/100/100) for the monophyly of this species. The species is very strongly supported (98/100/100) as sister to N. dubia Klapálek + N. proxima n. sp..

Notes. The presumed N. vicina n. sp. male resembles the other species in the complex. Tergites of Neoperla sp. Afr_A, originally the presumed male of N. muyukae , are also similar, but the penis and the female (if correctly associated) differ. Neoperla vicina n. sp. has almost as few egg striae as members of the N. transvaalensis-group .

Etymology. An adjective in female gender designating the species as neighbour (Lat. vicinus) of N. dubia and N. proxima n. sp.

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.

FIGURES 313–322. Males in the Neoperla dubia-complex: N. dubia Klapálek (from Makak, Cameroon): 313, terminal segments, dorsal view; 314, 315, enlarged centre of tergites 7 and 8, dorsal and lateral; 316, contracted, 317, everted penis with detail of distal armature (not to scale, from Ikom, Nigeria). Neoperla proxima n. sp.: 318, abdominal tip in dorsal view; 317, tip of penis with everted endophallus (D. R. Congo, Odzala N. P.). Neoperla vicina n. sp.: 320, 321, abdominal tip, dorsal and lateral views; 322, penis tip with everted endophallus in lateral view, and a detail of external spines in oblique lateral view (D. R. Congo, Bukavu). Scales in 317 and 322 are 100µm, scale in 320 is 0.5mm. The tergites, hemitergite 10 and the cercus are labeled.

FIGURES 323–331. Neoperla dubia-complex, femalesand eggs.N.dubia Klapálek:323, genital situs; 324, eggwith moderately raised costae (Ghana, Agumatsa waterfalls); 325–327, egg with flanged costae (D. R. Congo, Odzala N. P.). Neoperla proxima n. sp.: 328, genital situs (D. R.Congo, N of Matadi), 329, egg (Cameroon, Sangmelina). Neoperla vicina n. sp. (D.R. Congo): 330, female situs, 331,egg, arrow points at end of raised part of costa (paratype, Walikale, Z2101). Scales are 100µm, similar structures shown to the same scale. Top view of egg (326) based on combined halves of a photograph. Sa, spermatheca; SSt, spermathecal stalk; V, vagina.