Neoperla luluana Navás, 1931

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 : 38-39

10. Neoperla luluana Navás, 1931

( Figs. 50–55 )

Neoperla luluana Navás, 1931: 136 , fig. 72.

Type material studied: Democratic Republic of the Congo, ♀ Holotype : Holotype \ Musée du Congo Lulua: Riv. Luele [~ 10.88°S, 23.55°E, 1171m] 1929 Dr. Walker \ R. dét. 1943 \ Neoperla luluana Nav. P. Navás S. J. det. ( MRAC, pinned; genitalia cleared and stained with safranin and mounted in Xylol-soluble medium on plastic slide on specimen pin by P.Zwick in 1971) .

Habitus. Large, WL 19.3mm, wing span 43 mm. Light ochre, wings clear with light ochre tinge, darker towards tip. Head in front of M-line slightly brownish, an anteriorly pointed brownish spot between the ocelli. Ocelli about one diameter apart, their black rings are separate. Thorax of a greyish-yellow colour, the raised scuta of meso- and metathorax light brown. Appendages are of a dirty grey-brown, flagellum darker towards tip, most of front femur infuscate, in the hind femur only the apex, middle leg intermediate. Cerci missing.

Male. Unknown.

Female ( Fig. 50 ). S8 with short transverse subgenital plate. Vagina little longer than S8, with faint lateral sclerites and anterodorsal concentric folds. SSt attaches dorsally with a strong duct, details not visible. The duct is directed forward, at some distance from the vagina it widens, resembles a flat carrot and curves back. The thick wall of the duct continues on the concave side of the carrot-shaped section of SSt which has delicate folds or unpigmented microscopic spicules. The thin distal end carries the membranous irregularly curled spermatheca.

Egg ( Figs. 51–55 ). 415*265µm, drum-shaped, 10 straight ridges, wide shallow sulci. Operculum low, no collar, a ring of smooth cuticle surrounds the shallow anchor cavity from which rises a thick stem ending in numerous anchor filaments ( Figs. 51–52 , af). Chorion very thick, with dense fine unordered punctures. Short transverse cells along the eclosion line ( Fig. 55 , tc), detached top circular. Micropyles open on raised mounds traversed by the micropylar canal ( Figs 53–54 , mic), in vertical view the mounds look like impunctate rings around the orifices and micropylar canal ( Fig. 53 ).

DNA. No data.

Notes. The flat section of the spermathecal stalk resembles the N. transvaalensis -group by absence of some sclerotised armature but egg shape, structure of micropyles, and anchor are unique. Multifilamentous anchors occur also in the N. orthonema -group where, however, the anchor has no stem; instead, filaments supporting the cap arise directly from the anchor cavity. The only specimen was collected 80 years ago. The relationship to other species are unclear but the soft curled spermatheca and the keel-shaped egg costae suggest that N. luluana is more closely related to other African than to any exotic species.

Figures

FIGURES 50–55. Neoperla luluana Navás, ♀ holotype:50, genital situs, 51, egg, both diagrammatic; 52, detail of the filamentous anchor, the filaments attach to some thick chorion fragment; 53, vertical view onto a micropylar mound, 54, lateral view of same; 55, fraction of the eclosion line, at the end of a costa. Scale lines are 100µm, drawings are not to scale. af, anchor filaments; co, costa; mic, micropylar canal; op, operculum; sa, spermatheca; SSt, spermathecal stalk; su, sulcus; tc, transverse cells.