Neoperla pusilla, 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 : 83-85

35. Neoperla pusilla n. sp.

( Figs. 193–196 )

Type material. Holotype J: Republic of Sierra Leone, Pampana près de Magburaka [8.67°N, 11.96°W], 5.2.89 ( SMNS, gift Élouard; penis slide Z16.82, NEOP247 ).

Habitus. WL 7.2mm, two free branches of Rs. Yellow, flagellum distally slightly infuscate. Ocellar rings connected by a brown bridge which is narrower than an ocellus. Hind tibiae wide.

Male ( Figs. 193–196 ). T7 caudal process long and narrow, extending over all of T8, the downcurved tip almost meeting the humps on T9 ( Figs. 193–194 ). Base of triangular sclerite on T8 wider than process of T7, narrow rear end forming a small erect pimple. T9 unmodified, a pale furrow between pilose humps with SB. Medio-basal callus of HT10 rounded, plump. Process of HT10 short, stout, straight, resting on T9, barely visible in side view. Sternites unmodified.

Penis tubular, slender, bent dorsad in basal third; some external spines ventrally at tip. Endophallus short, hardly attaining half tube length. Base of endophallus dorsally with four dense regular series of stout spines distally decreasing in size. Ventral side with three rows of more slender spines, distal spines thinner and longer than basal ones ( Figs. 195–196 ).

Female. Unknown.

DNA ( Figs. 492 , 496 ). Only the male holotype from Sierra Leone was sequenced for the COX1 DNA barcode fragment. These DNA sequence data are insufficient to resolve the phylogenetic relationships of this species. The codon model analysis places this species without significant statistical support (60.7/84/75) as sister to the N. orthonema -complex + N. spio -complex. However, the species is placed in the very strongly supported cluster defined by node C (99.7/98/99), rather than in the morphologically defined N. pilulifera -complex.

Etymology. The name is the Latin adjective pusillus, minute, in the female gender.

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.

FIGURE 496. Partial (clades G, H) codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). See Fig. 493 for common details.

FIGURES 193–200. Neoperla pusilla n. sp. and N. multiserrata n. sp., holotype ♁♁. N. pusilla: 193, 194, abdominal tip; 195, everted penis; 196, basal portion of endophallus. N. multiserrata: 197, 198, abdominal tip; 199, everted penis (the subterminal constriction of the penis tube is an artifact); 200, everted endophallus. Abdomina in dorsal and lateral views, tergites and hemitergite10 labelled; arrows in 195 and 200 indicate ventro-apical spinules. Only 196 to scale.