Neoperla pilulifera, Zwick & Zwick, 2023

IV.2 The N. pilulifera -complex (~ clade F)

An endophallus with a long bare basal stretch ( Figs. 164 View FIGURES 161–168 , 177, 179 View FIGURES 177–180 , bbs) and an armature restricted to the distal section is shared by several males with pyramid-shaped process on T7 and flat or only slightly convex T8. Endophallus variable, recurrent tube never observed.

Females usually have an anchor pattern on S8. Concertina-like transverse folds at the base of the vagina suggest it can be much extended (e.g., Figs. 154 View FIGURES 154–160 , 167 View FIGURES 161–168 , cf). SSt covered with densely placed scales, length variable, between half and 1.5 circles are formed. The non-striate, smooth, and finely punctate eggs often resemble pills and are characteristic of the complex. Identification of females largely relies on eggs and is difficult.

Generally, in species with striate eggs the ends of costae are connected to cells on the collar. Several of the species have cells on the projecting collar ( Figs. 183, 185 View FIGURES 181–192 ), probably their ancestors had striate eggs.

The monophyly of the N. pilulifera -complex excluding N. pusilla sp. n. and N. multiserrata sp. n. (= clade F) is strongly supported (100/98/7) in the DNA sequence data analyses.

Keys to species

Males ( N. nichollsi , N. plicata , and N. cataractae unknown)

1 The penis is a very slender tube ( Figs. 153 View FIGURES 150–153 , 172 View FIGURES 169–176 )............................................................. 2

1' The penis is not strikingly slender, shape varies and may be rather short and wide.................................. 4

2 There are no external spines on the penis tube............................................................... 3

2' Groups of external spines occur in membranous windows far from the penis tip................... 30 N. pilulifera n. sp.

3 The endophallus base is inflated, its ventral spines stand more caudally than the apicodorsal spine patch on the penis tube, not opposite it. Beyond the bare basal stretch the endophallus bears dorsally a number of large hooks, the ventral face is completely bare ( Figs. 152–153 View FIGURES 150–153 ).................................................................... 26 N. caeleps n. sp.

3' Penis tip symmetrical, the few distal spines at the end of the tube and the few ventral spines on the endophallus base form a regular ring ( Figs. 179–180 View FIGURES 177–180 )............................................................. 33 N. cocculta n. sp.

4 Penis tube and base of everted endophallus stand in a straight line, the bare basal section of the endophallus is long ( Fig. 164 View FIGURES 161–168 ). Some males have dark wings and bicolorous legs ( Fig. 161 View FIGURES 161–168 )....................................29 N. amoena n. sp.

4' No straight basal area, the endophallus curves to the ventral side................................................ 5

5 The penis tip resembles a knee from which the curved endophallus originates. Dorsally the tip bears a crust-like cover of spines. Distally the endophallus is curved, the wide tip dorsally with very many, ventrally only with few spines in a narrow band ( Figs. 174–176 View FIGURES 169–176 )............................................................................ 32 N. crustata n. sp.

5' Penis slender with few apical spines, endophallus almost straight, conical, distal half with many dorsal and few ventral spines ( Figs. 177–178 View FIGURES 177–180 )......................................................................31 N. aethiopica n. sp.

Females ( aethiopica , caeleps , crustata unknown)

1 SSt long, forming more than one complete circle (e.g., Figs. 97, 99 View FIGURES 96–101 )............................................. 2

1' SSt short, forming at most one complete circle, often less..................................................... 3

2 S8 without pattern, the vagina slender, unmodified. Egg striate, contour oval with low cap-like operculum ( Figs. 99–101 View FIGURES 96–101 ).....................................................................................21 N. cataractae n. sp.

2' S8 with a pale anchor-pattern, the slender vagina with lateral sclerite rods. Egg without striae, both poles narrow, equatorial region wide ( Figs. 154–156 View FIGURES 154–160 )...............................................................27 N. plicata n. sp.

3 Egg pear-shaped, without collar ( Fig. 159 View FIGURES 154–160 ).................................................... 28 N. pirus n. sp.

3' Egg subspherical or oval, with collar (e.g., Figs. 168 View FIGURES 161–168 , 182, 189 View FIGURES 181–192 )................................................. 4

4 Egg subspherical, collar wide, corresponding to approximately 17% of maximum egg width, length of collar varies. Anchor with thick stem, cap large............................................................................... 5

4' Egg oval, with gently curved sides, poles similar. Collar narrow, width corresponds to roughly 1/10 of egg width. Anchor delicate, stem narrow.................................................................................. 6

5 Spermathecal coil a wide half ring with short plump end ( Fig. 167 View FIGURES 161–168 )...............................29 N. amoena n. sp.

5' Spermathecal coil longer and less wide, distally slender ( Figs. 181, 186, 188 View FIGURES 181–192 )..................... 30 N. pilulifera n. sp.

6 Egg oval, distinctly longer than wide, short parallel collar with simple rim ( Fig. 187 View FIGURES 181–192 )................ 33 N. cocculta n. sp.

6' Egg nearly spherical, collar long, funnel-shaped, rim large, scalloped ( Figs. 189–190 View FIGURES 181–192 )............... 34 N. nichollsi n. sp.