Neoperla didita (Enderlein, 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 : 48-50

17. Neoperla didita (Enderlein, 1909)

( Figs. 83–86 )

Ochthopetina didita Enderlein, 1909b: 345 .

Type material studied: Republic of Cameroon, ♀ Lectotype from Barombi [Kumba], redescription: Zwick 1973a: 504, figs. 74, 75. Not examined again now. In MIZ, type No. 1302. The paralectotype is a misassociated N. africana n. sp., see below.

Additional material. Republic of Cameroon: 1♀: Brinck XI 05 Sappo, Buea [4°9’N, 9°14’E], British Cameroons, IV-21 S.Tita ; 1♀: Brinck XI 03; Mamfe [5°46’N, 9°17’E], British Cameroons, 8–11.I.1949 (at light, B. Malkin, MfNB) .

Habitus. WL approximately 11 mm. Light ochre, wings slightly infuscate. The small ocelli stand on a small dark spot, separate by their own diameter. Body without pattern, flagellum, distal part of cercus, tibia and tarsus darker.

Male. Unknown.

Female ( Fig. 83 ). S8 unmodified, a small area on S8 of the lectotype stained with Safranin, i.e., is a little sclerotised ( Ludwig & Schmidbauer 1967, Zwick 1973a). Vagina ( Fig. 83 ) with some transverse folds near base, a small pile of folds on top of vagina, behind SSt attachment. SSt forming a coil of ~1.5 rings, the very wide base with strong undulating folds and probably very extensible. A narrow band of brown cuticular scales along convex side of base widens gradually. Narrow distal half of the coil crowded with reddish to brownish spicules, except along the concave edge. Individual scales are slender but are too crowded to recognize details of shape.

Egg ( Figs. 84–86 ). Spindle-shaped, 430*250µm (lectotype), 360*220µm (specimen from Mamfe), widest at midlength, both poles narrow, no collar ( Figs. 84–85 ). Mushroom-shaped anchor just large enough to cover the narrow opening of the anchor cavity ( Fig. 86 ). About 20 straight narrow impunctate ridges extend between the edge of the anchor cavity and a few deep cells on top of the operculum. Chorion between ridges with very fine unordered punctures visible at ~200*. Micropyles freely visible, located a little beyond midlength of egg.

Variation. In the type, cells surround an indistinct shallow depression on the anchor pole, the anchor is missing ( Fig. 84 ). In the female from Mamfe the apical depression is larger and deeper, the thin anchor stem inserts in it ( Fig. 85 ).

DNA. No data.

Note. The close relationship with N. juxtadidita is obvious. Enderlein did not explain his choice of the name ( didita —dispersed). The redescription of the lectotype (Zwick 1973: figs. 74–75) contains two artifacts caused by maceration and the hot safranin stain of the lectotype. One, the treatment caused a slight spin of the egg ridges. Two, it stretched the spermathecal coil out. Because of lack of material, N. didita is not well known but N. juxtadidita n. sp. seems to be different.

Figures

FIGURES83–90.Neoperladidita(Enderlein)andN.juxtadiditan.sp.:N.didita:83,spermathecalstalkofthefemalefromMamfe; 84,fragment ofan eggfromthe lectotype;85,eggof thespecimenfrom Mamfe;86,anchor poleofsame,opticalsectionandsurface view combined (diagrammatic, from a photograph). N.juxtadidita: 87, genital situs of holotype female from Belinga; 88, spinules from inside the spermathecal stalk; 89, egg; 90, anchor pole with anchor.Scales are 100µm, 84, 85 to the same, others not to scale. a, anchor; c, collar; r, ridges on egg; sa, spermatheca; SSt, spermathecal stalk; V, vagina.