Chimarra waensis Gibon, 1985

Blahnik, Roger & Andersen, Trond, 2022, New species of the genus Chimarra Stephens from Africa (Trichoptera, Philopotamidae) and characterization of the African groups and subgroups of the genus, ZooKeys 1111, pp. 43-198 : 43

Chimarra waensis Gibon, 1985

Fig. 23A-E

Chimarra waensis Gibon, 1985: 26, figs 9-10.

Material examined.

Ghana - Brong Ahafo Reg. ● 1♀; Asubende, River Pru; 8°01'18"N, 1°01'58"W; 24 Nov. 1990; JS Amakye leg.; light trap; ZMBN. - Northern Reg. ● 1♀; Sabari, Oti River ; 9°17'41"N, 0°14'43"E; 22-24 Nov. 1991; JS Amakye leg.; Malaise trap; ZMBN. - Upper East Reg. ● 1♀; Nangodi, Nangodi Bridge; 10°51'48"N, 0°39'36"W; 26 June 1993; JS Amakye leg.; light trap; ZMBN. - Volta Reg. ● 1♀; Wli, Agumatsa waterfall, station # 12; 7°07'29"N, 0°35'31"E; 16 Nov. 1993; J Kjærandsen leg.; light trap; ZMBN. - Western Reg. ● 2♀♀; Ankasa Game Production Reserve ; 5°15'N, 2°37'W; 6-12 Dec. 1993; T Andersen & J Kjærandsen leg.; Malaise trap; ZMBN ● 1♀; same collection data as for preceding except 9 Dec. 1993; J Kjærandsen leg.; light trap; UMSP ● 1♂; same collection data as for preceding except 31 Mar. 1993; J Kjærandsen leg.; light trap; UMSP ● 1♀; same collection data as for preceding; ZMBN ● 7♀♀; same collection data as for preceding except 8-10 Dec. 1993; T Andersen & J Kjærandsen leg.; ZMBN .

Diagnosis.

Characters, in combination, that confirm the identification and can be used to distinguish C. waensis from other species in the subgroup include: length and position of digitate process of tergum X; general shape and length of inferior appendage; subtriangular shape of ventral process of tergum X; the single, moderately elongate phallic spine; and the curved, projecting apex of the phallobase. The anterior margin of segment IX, in the original illustration of C. waensis ( Gibon 1985: fig. 10), is less sinuate than in our illustration. Particularly, the prominent dorsal apodeme is not featured. This is more likely a deficit in the illustration than a genuine difference, since the anterior contour of the segment, as illustrated in Fig. 23A , is not characteristic of any species of the Chimarrha kenyana subgroup. We consider the matching features sufficient to justify the use of the name C. waensis to identify our specimen.

Both C. baculifera Marlier and C. camerunensis Marlier are also very similar to C. waensis , particularly in the general shape of the inferior appendages, which are elongate and narrow, with a characteristic subtruncate apex. All of these species also have elongated, curved, sensilla-bearing processes on the lateral lobes of tergum X, and a similar, basally broad, subtriangular ventral process on segment IX. We initially considered synonymizing all of these species. Restraint in doing so was based on the very acutely angled anteroventral margin of segment IX in the original illustration of C. baculifera , and the very elongate phallic spine featured in the original illustration of C. camerunensis . Since these kinds of differences are not usually attributable to intraspecific variation, a more critical evaluation, provided by comparison of holotype specimens, ideally in the context of a formal revision of the entire subgroup, should probably precede any synonymy.

Redescription.

Adult. Overall color (in alcohol) pale yellowish brown. Head elongate (postocular parietal sclerite slightly shorter than diameter of eye). Palps elongate; maxillary palp with 1st segment very short (length subequal to width), 2nd segment elongate (slightly longer than 3rd), apex with cluster of stiff setae, 3rd segment moderately elongate (normal), 4th segment short (~ 2 × 1st), 5th segment elongate (subequal to 3rd). Forewing length: male, 5.7 mm; female, 4.5-5.0 mm. Fore- and hind wings with forks I, II, III, and V present. Forewing with R1 distinctly sinuous, stem of Rs inflected at past midlength, with node extending into cell below, discoidal cell short, length slightly greater than width, basal fork not enlarged, forks I and II sessile, r crossvein diagonal, intersecting discoidal cell at approximately midlength, r-m crossvein of forewing diagonal, slightly proximal to s, m crossvein very faint, proximal to r-m, very near basal fork of M, 2A with crossvein (apparently forked apically to 1A and 3A). Hind wing with R1 fused to subcosta basally, both veins intersecting wing margin, discoidal cell short, forks I and II elongate, sessile. Foreleg with apical tibial spur short; male with foretarsi unmodified, claws small and symmetrical.

Male genitalia. Segment VIII short, sternum and tergum subequal in length. Segment IX, in lateral view, relatively short, anterior margin distinctly, subangularly, produced in ventral ¼, dorsolaterally with very prominent, broadly rounded apodeme, nearly as projecting as ventral production, margin concave between; tergum, in dorsal view, very short and narrowly sclerotized, but continuous dorsally, or nearly so, forming excavation between apodemes; posterior margin obliquely and somewhat convexly widened from preanal appendage to ventral process; ventral process prominent, subtriangular, wide basally, only weakly projecting. Segment IX, in dorsal or ventral views, with anteroventral margin moderately, concavely excavated mesally. Lateral lobes of tergum X elongate, subtruncately rounded apically, somewhat dorsally produced in basal half, basodorsally with elongate, posteriorly oriented, digitate, sensilla-bearing process; lateral lobes, in dorsal view, subparallel; mesal lobe of tergum X membranous, approximately as long as lateral lobes. Preanal appendages short, constricted basally, knob-like. Inferior appendage, in lateral view, elongate, narrow, nearly uniform in width, distinctly dorsally flexed near base, apex slightly narrowed, forming subtruncate, weakly notched or bifid process; appendage, in dorsal or ventral views, more or less uniformly mesally curved, curvature moderate. Phallic apparatus with phallobase relatively short and tubular, with usual basodorsal expansion, apicoventral margin distinctly projecting and deflexed, apex acute and even more strongly ventrally curved; endotheca with single, moderately elongate spine; phallotremal sclerite complex composed of short rod and ring structure, with small, indistinct apicolateral sclerites.

Distribution.

Ghana, Ivory Coast.

Figures

Figure 23. Chimarra waensis Gibon, ♂ genitalia A lateral B dorsal, segments IX and X C inferior appendage, ventral D inferior appendage, dorsal E phallus, lateral.