Neoperla kalengonis, 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 : 32-34

6. Neoperla kalengonis n. sp.

( Figs. 26–32 )

Neoperla sp. 26— Zwick 1976a: 686, figs. 2, 6, 9, 687, Table 1.

Type material studied: Democratic Republic of the Congo, ♀ holotype ( NEOP013 ) , 1J paratype ( NEOP012 , Z73/2M) , 1♀ paratype (Z73/2) 4♀, 3♁ additional paratypes: emergence trap on the stream Kalengo [~-2.2, 28.7], western slopes of the Central African Rift Valley, near Lwiro, 10km W of Lake Kivu, 1750–1800m, 1972– 1973 (B̂ttger 1975) ( PZ) . Additional paratypes: 1♁: B.Congo: Lwiro River , 47km N.of Bukavu [-2.49, 28.84], 1950m, XII-15-57 ( CASENT 8413007 ) ; 4♁: B. Congo, Mutwanga [0.34N, 29.75E], 1200m, IX-23-57, Ross & Leech ( CASENT 8413013 ) ; 1 ♀ Kankunda [5.11°S, 27.15°E] (r. dr. Lupiala ) 1300m 13.–27.XI.1947, Mission de Witte Nr. 963a \ Hynes det. N. spio ( NEOP011 , pinned slide; MRAC) .

Additional material studied. Democratic Republic of the Congo: 22♀, 25♁ taken with the types ( SMNS); Riv. Lwiru, Katana [W shore of Lake Kivu, 1460m: Institut Parcs Nat. Congo Belge 1946; Inst. Géogr. Militaire Belg. 1961] No.5, 15-12-49, 1♁; No.1, Riv. Thriganda, Bunyakiri [2.09°S, 28.57°E, 1094m], 26.3.50, 1♁; same locality, No.3, 27.3.50, 1♁; Riv. Tshifu, affl. Luhoho, Bunyakiri, 29.3.50, 1♀; Butembo [0.11°N, 29.30°E, 1762m], Riv. Ibina, 10.2.50, 1♁; Rivière Mugaja, Uvira [3.37°S, 29.15°E, 784m], 1-10-52, 1♀ (all G.Marlier, MNHN). B.Congo: Lwiro River, 47km N.of Bukavu, 1950m, XII-15-57, 1♀ ( CASENT 8413015, slide Z17.58); B.CONGO: Lusinga, Park Upemba [-9.0018, 26.7490], I-17-58, 1800m, 1♁ ( CASENT 8413014). 1♀: Congo Belge Kivu Masisi Le Moult. 1938 ( SMNS). Republic of Kenya: 1♁ (Hynes det. N. spio ), 1♀, Brit. E. Africa, Ilala, Maramas Dist. 14 m E of Mumias [0.32°S, 34.49°E], 4500ft June 18–21, 1911, S.A.Neave ( BMNH). A misassociated paralectotype of N. arambourgana Nav. (lectotype designated below): 1♀, Kenya Suam fishing hut Mt. Elgon vers’ est 2400m \ Museum Paris Mission de l’Omo C.Arambourg, P.A.Chappuis & R.Jeannel 1932–33 \ Neoperla arambourgana Nav. det. Navás S.J. (in Navás’ hand) \ TYPE ( MNHN, egg slide also in PZ). Republic of South Sudan: Gilo [4.04S, 32.85E] at light 18–27 Oct. 1979 A.L.Armstrong, 1♀ ( USNM 47, pinned through pronotum, genitalia and egg fragments on pinned slide). Pharate female nymph with a few mature eggs: Gribol Kinyetti River 16 April 1979 Andrea L. Armstrong (genitalia & egg slide; USNM- 137).

Habitus. Large, WL of ♁ 13.2–14.3mm, of ♀ 16.0–18.0mm. Rs with 2–4 free branches. Pale species, no pattern, narrow ocellar rings separate, flagellum light brown, cercus pale.

Male ( Figs. 26–27 ). Tergites not distinctive, HT10 with straight long process, tip obtuse, edge of S8 without row of setae. Penis long, everted endophallus almost straight, about 1.5 times longer than the penis tube, endophallus base with a dense patch of small stout spinules, its basolateral corners drawn out into narrow bands of spinules. Most of endophallus with many long slender straight spines. Dorsobasally, opposite the spine patch, projects a bare cone from which a narrow bare strip continues to the endophallus tip. A long recurrent duct is visible in a few slide mounts.

Female ( Fig. 28 ). S8 forms a short indistinctly bilobed light brown lip. Vagina unmodified, without large folds on top. SSt very long and slender, inside with a dense pelt of slender reddish spines, several distally divided. The forward-directed base of SSt is wide, the reddish spines aggregate in undulating folds. The back-curved distal section of SSt is longer, no strong internal folds. Spermatheca long, curled ( Fig. 28 ).

Egg ( Figs. 29–32 ). 437*236µm (holotype) to 456*233µm (misassoc. paratype of N. arambourgana ), plump, with 11–12 ridges. Micropyles are freely visible in the wide spaces between ridges, the coarse punctures stand in transverse rows and grow finer towards ridge tops. Operculum a low triangular cap with unordered fine punctation. A constriction separates ridges from the large inflated collar which has no distinct cells, rim with minimal flange. Stem of mushroom-like anchor long.

Variation The species is known from localities on the western edge of the East African Rift Valley, from an area near Mt Nyiragongo (formerly Mt. Kivu), north to South Sudan. Shape of the wide egg collar varies between sites, in Sudanese females it is smaller than in the typical morph ( Figs. 29, 31 ). SSt always typical.

DNA ( Figs. 491–493 ). Only three specimens from D. R. Congo were sequenced with genome skimming, obtaining near identical mitochondrial genome data for the female holotype and male / female paratypes (monophyly maximally supported with 100/100/100). The species is well-supported (46.7/98/99) as sister to N. lujana Navás .

Notes. B̂ttger (1975) provides details of collecting methods employed at the type locality. Emergence from the Kalengo stream was non-seasonal ( Zwick 1976a), despite strongly seasonal rain fall (Viets & B̂ttger 1974, who also list some accompanying fauna).

Etymology. A noun in apposition, in the genitive case, a dedication to the type stream.

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 26–32.Neoperla kalengonisn. sp.: 26, artificiallyevertedpenis ofa paratype;27, spines on endophallus of same, scale is 50µm; 28, paratype ♀, genital situs; 29, 30, eggs of paratypes, 30 courtesy of MPI of Limnology; 31, egg from South Sudan; 32, anchorpoleandcollarofeggfromLwiroR.Scalesare100µmunlessdifferentlyindicated,30nottoscale,29and31tothesamescale. sa, spermatheca; SSt, spermathecal stalk.