Neoperla excavata, 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 : 153-154

73. Neoperla excavata n. sp.

(Figs, 418–421)

Type material. ♀ holotype: Gabonese Republic: Gabun , Belinga 155L, Coiffait ( SMNS, gift of C. Berthélemy, SMNS; NEOP299 )

Habitus. WL 12mm. Yellowish brown, wings slightly tinged, femora light, tibiae somewhat infuscate. Scapus light, flagellum brown. Cercus pale at base, brownish towards tip. A poorly delimited brown spot between the eyes extends forward and is also expanded sidewards, around the tentorial calluses.

Male. Unknown.

Female ( Fig. 418 ). S8 with wide notch between pointed corners. A sclerite with convergent sides and truncate front extends into the vagina from the segment edge. Each side of the widest part of the sclerite bears a short oblique crest. Vagina unmodified, with concentric folds around the base of SSt which is of uniform width and about two rings long. It is entirely paved by pointed scales. Spermatheca delicate, coiled (not shown in the figure).

Egg ( Figs. 419–421 ). Size 342*202µm, plump, numerous straight striae between the rim-like collar and the wide, bluntly rounded shallow operculum. Costae wide, flat, impunctate, sulci extremely narrow, with 2 lines of micropunctures which barely diverge around the micropyles ( Fig. 421 ). Anchor cavity shallow, anchor with short, wide stem and a massive little disc closing the collar like a plug ( Fig. 420 ). Very fine unordered punctures on the operculum, in optical section they appear like radial lines in the thick chorion.

DNA ( Figs. 492 , 498). The female holotype from Gabon, the only known specimen, was sequenced for the COX1 DNA barcode fragment. Its sister relationship to a large part of the N. sjostedti -group is moderately supported (77.3/98/82), in line with the limited amount of data available.

Notes. In the wide notch with firm edge on S 8 N. excavata n. sp. resembles N. gibbosa n. sp. but lacks dense pilosity on S8 and eggs have straight instead of spiral striae.

Etymology. The Latin adjective excavata , excised, describes S8.

Figures

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 418–421. Neoperla excavata n. sp., ♀ holotype: 418, genital situs, spermatheca not shown; 419, egg; 420, optical section though anchor pole of another egg, scale is 50µm; 421, detail of striae from region marked in Fig. 419. Scales are 100µm; a, anchor; c, collar; mi, micropyle; SSt, spermathecal stalk; V, vagina; vscl, vaginal sclerite.