Neoperla crenulata, 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 : 154-156

74. Neoperla crenulata n. sp.

( Figs. 422–428 )

Type material. Republic of Cameroon: Holotype ♀, Akom [2.7866 N, 11.304], 450m, 18.X.66, Ross & Lorenzen ( CASENT 8413078 ) ( NEOP304 ); 1 Paratype ♀, Ikom [6°5’N, 8°37’E], Ogoja Prov. , Federal Republic of Nigeria. 25.. I.1949 B.Malkin, at light ( SMNS).

Presumed males. 1♁, Republic of Cameroon, Akom [= Cma D’akom li; 2.8617N, 10.5545E], 450m , 18.X.66, Ross & Lorenzen (Z18.42, CASENT 8413076 ). 1 ♁, Kumba [4°38’M, 9°27’E] , Cameroon, light trap, early Dec.1952, lg. Nicholas (penis on slide; SMNS, gift Hynes); 2 ♁, Kumba [4°38’M, 9°27’E] , British Cameroons, 19.I.1949 (at light) B. Malkin ( ZMB and SMNS). 1♁, Libamba 10km E of Makak 20–29-IX-1973 filtered black light, J.A.Gruwell ( USNM _91) .

Habitus. Female WL 9.8–10.3mm, WL of presumed male 8.5–9.5mm. Yellow, ocellar spot brown, cercus apically gradually darkened.

Male (presumed). Caudal process of T7 transverse, raised, caudally delimited by a transverse concave fold. The hook on T8 is rather narrow. T9 is short and little apparent between T8 and T10, antecosta 9 medially interrupted, the pilose lateral humps are transverse swellings, the median furrow is shallow. Hemitergal callus large, upper face concave, the anterior process concave, the blunt tip directed forward ( Fig. 422 ). Penis approximately 1.0 mm long, a firm slightly curved slender tube, apex bent like a knee ( Figs. 423–424 ). Opposite the bend is a small subterminal cone (arrow in the figures). Endophallus shorter than the penis, base wide and bare, narrowing abruptly, numerous small spines on dorsal side, opposite them a short ventral row of erect slender teeth (open arrow in inset of Fig. 424 ). Distal section bare.

Female ( Fig. 425 ). S8 soft, unmodified but the floor of the genital cavity bears a short and wide sclerite which seems to be a short forward-shifted nail with arched raised front edge. Vagina calyx-shaped, unmodified. The SSt is only roughly 1.5 times longer than the vagina and internally scaly.

Egg ( Figs. 426–428 ). Size 328*192µm. Elongate oval, sides only gently curved, operculum rounded ( Fig. 426 ). Collar narrow, with two rings of cells. Anchor small, mushroom-shaped, inserted in a central depression in of the low anchor cavity. Operculum with dense, deep, and large punctures. About 25 straight striae, costae in vertical view with a zig-zag pattern ( Fig. 427 ). In profile two rows of different processes on each costa are recognised: blunt cones and truncate spikes alternate ( Fig. 428 ) and are displaced by one position relative to the neighbouring row, each spike stands next to a cone. The ends of costae lack spikes, a pale ring resembling an eclosion line results. Sulci are deep and narrow and do not widen around micropyles which are hard to find among the complex chorion structures.

DNA ( Figs. 491–492 , 498). Only the female holotype from Cameroon was sequenced with the genome-skimming approach, resulting in 10,308bp of mitochondrial, protein-coding genes. Its sister relationship to N. massevensis n. sp. + N. tangana n. sp. is strongly supported (94.1/100/91).

Etymology. The Latin adjective crenulata refers to the crenulate egg costae.

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 422–428. Neoperla crenulata n. sp. Presumed male: 422, abdominal tip; 423, penis; 424, everted endophallus, with enlarged detail. ♀ holotype: 425, genital situs; 426, egg; 427, detail of chorion structure, direct view of surface; 428, same, oblique view of profile. Scales are 100µm in 423–426, 50µm in 427 and 428. Tergites, hemitergite10 and epiproct are labeled. c, collar; n, nail; sa, spermatheca; sc, small cone opposite knee-like bend of penis; SSt, spermathecal stalk; V, vagina.