Neoperla sjostedti, Klapalek, 1909

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 : 167-169

79. Neoperla sjostedti cf. needhami

( Fig. 457 )

Material studied. Republic of Cameroon, 8♀, 6°8’26.25’’N, 10°6’3-68’’ E, NW Reg., Bamenda, Mentchum River contributor 15 km NNW Bafut, 630m asl, 9 Nov.2011, MV-lamp ( NEOP325 , NEOP326 , NEOP327 , NEOP328 , NEOP329 , NEOP330 , NEOP331 , NEOP332 ; SMNS) . Republic of Kenya, 1♀: KENIA, Lake Turkana, Sibiloi National Park [3.92N, 36.18], Koobi Fora Base Camp 14.3.1988 ( HNHM, slide Z19.75) .

Habitus. WL 11.5–13.2mm. Pale, cerci yellow, apically gradually darkened.

Male. Unknown.

Female ( Fig. 457 ). S8 with a short wide nail, the inner part with anterolateral crests is longer than the projecting part. Vagina unmodified, SSt coiled, about 2–3 rings with a complete brown stout scale band which is almost half as wide as the nail, only the terminal section is narrower.

Egg. Regularly ovoid, on average 338*178µm, anchor pole and operculum are of similar width. Numerous straight shallow striae, costae and sulci lie on almost the same level. Surface of costae smooth, the narrow sulci with two lines of micropunctures and elongate widenings for the micropyles. Operculum parabolic, with shallow cells. Collar with one ring of cells. Anchor mushroom-like, stem solid.

DNA ( Figs. 492 , 498). A total of eight female specimens from Cameroon were sequenced for the COX1 DNA barcode fragment. Their sequences are identical and form a distinct cluster within the N. sjostedti needhami cluster, which is in line with these female specimens differing morphologically from typical N. sjostedti needhami . Describing this distinct population from Cameroon as a separate subspecies would require description of several other taxa to retain reciprocal monophyly of all taxa. As females of the named subspecies of S. sjostedti cannot be reliably distinguished, these specimens from Cameroon are explicitly characterised, but not formally described as a new subspecies.

Notes. The main morphological differences between the present females and other members of the sjostedticluster are the short, thick, and completely scaly SSt lacking bare basal regions, the anterolateral crests at the front of the nail, and the ovoid (as opposed to club-shaped) egg.

V.2. The Neoperla arambourgana -complex (= clade L)

This complex includes N. arambourgana , N. dundoana n. sp., and N. leroiana . Sternites of males are unmodified, the middle of T7 is slightly raised caudally, and the elevated part is slightly concave between low paramedian humps. T8 has a forward-curved process or a strong hook. Males also share an inconspicuous process between the lateral humps on T9; it is most distinct in N. arambourgana ( Fig. 459 , black arrow). The straight tubular penis narrows distally a little, the tip is soft, often annulated and curved. The everted endophallus curves ventrad.

In most African Neoperla , spines on the basal section of endophallus are distributed dorsoventrally. In the present group the largest spines form two lateral rows near the base there are no other spines. Distally, smaller spines appear between the rows. Distally, all spines disappear but transparent membranes and a thin thread extend back to near the basal penis foramen. Details were not visible by transparency; the penes of a few specimens were therefore broken and the endophallus extracted ( Fig. 438 ). The extracted middle portion of the endophallus resembles a very wide trachea. In several preparations the terminal structures appear to be somewhat inflated.

Caudal edge of female S8 variable, with a sclerotised nail or notch. Vagina unmodified, the SSt is a densely spinose slender tube of uniform width and moderate length, forming 1.5–~4 rings. The ovoid eggs have numerous straight or levogyrous striae, the bare costae are wider than the narrow sulci which are impunctate, except two rows of micropunctures.

The monophyly of the N. arambourgana -complex (= clade L) is maximally supported (100/100/100) by the

DNA sequence data analyses ( Figs. 491–492 , 497). Its sister group relation to the N. sjostedti -complex (clade K) is also maximally supported (100/100/100).

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 450–457. Neoperla sjostedti needhami Lestage and N. sp. aff. sjostedti. N. s. needhami: 450, 451, abdominal tip and contracted penis of the N. needhami lectotype; 452, ♁ from Pampana, Sierra Leone; 453, ♁ from Tukuyu, Tansania; 454, ♁ from Illubabaor, Ethiopia. Scales are 0.5mm, except for the details in 451; asterisks identify the caecum of penis. 455, 456, ♀ genital situs and an egg, Ethiopia, NW of Chora. N. sp. aff. N. sjostedti (by DNA) from Mentchum River, Cameroon: 457, ♀ genital situs. Scale is 100µm. Scales are 100µm; n, nail; sa, spermatheca; SSt, spermathecal stalk; V, vagina.

FIGURES 459–465. Neoperla arambourgana Navás: ♁ lectotype: 459, diagrammatic dorsal and lateral views of abdominal tip, tergites, hemitergite 10 and cercus labeled; 460: distal half of penis. 461, process on T8 of ♁ from Rutshuru, D. R. Congo, diagrammatic; 462, endophallus of ♁ from Walikale, D. R.Congo.♀ genital situs:463, riv. Eulya, nr Kamituga, D. R. Congo; 464, Urwald Mawambi, D. R. Congo; 465, from Kama, D. R. Congo. Scales are 100µm, unless differently labeled; sa, spermatheca; SSt., spermathecal stalk; V, vagina.

FIGURES 432–438. Neoperla tangana n. sp.: 432, 433, ♁ abdominal tip, segments, hemitergite 10, cercus and epiproct labeled, not to scale; 434, penis (holotype, NEOP300); 435, distal half of penis (paratype, NEOP301); 436, ♀ genital situs; 437, egg; 438, detail of chorion. Scales are 100µm, unless differently labeled. co, common oviduct; D, debris, dirt; sa, spermatheca; SSt, spermathecal stalk; V, vagina.