Neoperla angolana, 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 : 42-44

13. Neoperla angolana n. sp.

( Figs. 63–68 )

Material studied: Republic of Angola, 1♀ Holotype ( CASENT 8413125 ), 1 ♁ Paratype ( CASENT8413126 ): 4 mi W Salazar 700m 5.xii.1966 E.S. Ross & K. Lorenzen (Z21.06 + 07) .

Habitus. Light ochre, ocellar spot largely faded, flagellum infuscate. Only ~10 segments of cercus available, the last 2 infuscate. Wings infuscate, WL ♁ 9.2mm, ♀ ~ 10.5mm (tip damaged).

Male ( Figs. 63–65 ). Hind tibia unmodified. T7 uniformly pigmented, without pale lines or marks, with a stout erect knob on the caudal margin which has very few SB on the raised underside. T8 has a small raised process with several SB, in dorsal view it is concealed under the process of T7. Behind the process a weak sclerite band extends to the soft space behind the (invisible) antecosta 9. The paramedian humps on T9 bear some SB and setae and are separated by a shallow short furrow, at the end of which rises a little cone with some SB. HT10 with broadly rounded hemitergal callus and a short and wide almost straight process with rounded tip. It stands at an angle of 45° to the body axis, is not raised and not visible in side view. The Y-shaped epiproct is flat and wide ( Fig. 63 ).

The penis (in two fragments) is a moderately sclerotised straight tube narrowing distad ( Fig. 64 ). The distal end of the penis and the base of the straight endophallus are membranous, there are no external spicules. Sharp triangular spines on oval bases are dispersed on the endophallus, the basal spines are large, size decreases distally, only granules remain near the tip ( Fig. 65 ).

Female ( Fig. 66 ). S8 unmodified, genital opening wide, convergent lateral folds lead to the calyx-shaped unmodified vagina. Concentric folds sit on the front of the vagina, the SSt is attached in the center. The SSt is a pale, gently curved wide tube with an armature of only very delicate unpigmented spicules on a narrow strip along the convex periphery. Some undulating folds occur near midlength. The curled spermatheca is delicate.

Egg (Fìgs. 67–68) is a slender ovoid sized 390*185µm, with short collar. There are some obsolete polygones on the narrow parabolic operculum which is irregularly punctate. Approximately 25 straight striae are present; the smooth flat costae and the shallow irregularly punctate sulci are of similar width, micropyles are visible and unmodified. Chorion fractions show that the egg surface is almost flat, without distinct relief. Collar with two rings of cells with low walls. The anchor cavity is funnel-shaped and deep, anchor mushroom-shaped, with entire stem and a large bell-shaped cap.

DNA. No data.

Note. The endophallus was torn during manipulation, details are nevertheless well visible in the slide mount. Genders are regarded as conspecific because they were taken together and were found nowhere else. Neoperla angolana belongs to the small complex of relatively primitive species between the transvaalensis - and africana - groups. Other females in the same complex with barely curved to almost finger-like and weakly armed SSt are of N. duodeviginti and N. pallidogigas ,.

Etymology. The Latin name of the species is an adjective referring to the country of origin.

Figures

FIGURES 63–68. Neoperla angolana n. sp.: 63, abdominal tip of ♁ paratype, dorsal, tergites numbered, not to scale; 64, partly everted penis; 65, endophallus of same. 66, genital situs of ♀ holotype, with enlarged detail, diagrammatic; 67, egg; 68, detail of chorion structure. Scales as indicated. ce, cercus; co, common oviduct; E, epiproct; sa, spermatheca; SSt, spermathecal stalk; V, vagina.