Chimarra multisensillata, Blahnik & Andersen, 2022

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 multisensillata sp. nov.

Fig. 36A-F

Type material.

Holotype. Tanzania - Tanga Reg. ● ♂ (in alcohol); East Usambara Mts, Fanusi; 28 Feb. 1959; 1.000 ft; MT Gillies leg.; INHS Trichoptera 50336.

Diagnosis.

Chimarra multisensillata is a distinctive species, unlike any other described species, with several unusual characteristics. Its most diagnostic feature is the shape of the inferior appendage, which has a narrow, sclerotized, digitate projection on the dorsal margin at just past midlength, that is oriented more or less parallel to the appendage itself. Also distinctive is the overall form of the lateral lobes of tergum X, which are very elongate and simple in structure, with ~ 10 unraised sensilla scattered laterally along its length. Another unusual characteristic, for a species in the Chimarrha marginata Group, is the relatively elongate, tubular phallobase with two elongate, sclerotized, symmetrically arranged spines, possibly modified elements of the phallotremal sclerite complex. Finally, the shape of segment IX is also unusual in having is anterior margin uniformly concave and its ventral margin strongly produced, with lateral margins that are somewhat convergent, as viewed dorsally or ventrally.

Because of having multiple sensilla on tergum X, rather than just two, as is typical of species in the Chimarrha marginata Group, one might question its placement in the group. Its venational characters, however, are typical of species in the Chimarrha marginata Group. Nevertheless, it probably represents a relatively basal species in the lineage.

Description.

Adult. Overall color (in alcohol) yellowish brown. Head relatively short (postocular parietal sclerite <1/2 diameter of eye). Palps moderately elongate, maxillary palp with 1st segment short (length subequal to width), 2nd segment short (~ 2 × 1st), apex with small cluster of stiff setae, 3rd elongate (> 2 × as long as 2nd), 4th segment short (subequal to 2nd), 5th segment very elongate (longer than 3rd). Forewing length: male, 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 just past midlength, with small node at inflection, not extending into cell below, basal fork of discoidal cell enlarged, fork asymmetric, discoidal cell with length ~ 2 × width, fork I sessile, fork II stalked, r crossvein diagonal, intersecting discoidal cell at past midlength, r-m crossvein continuous with s, m crossvein proximal to s and r-m crossveins, approximately midway between basal fork of M and r-m crossvein, s pigmented (like wing), r-m and m crossveins hyaline, very faint, 2A with crossvein (apparently forked apically to 1A and 3A). Hind wing with R1 fused to subcosta basally, both veins intersecting margin of wing, fork I sessile, fork II stalked. Foreleg with apical tibial spur distinct; male with foretarsi unmodified, segments very narrow, claws small and symmetrical.

Male genitalia. Segment VIII with sternum relatively short, with short ventromesal projection, tergum approximately same length. Segment IX, in lateral view, relatively elongate, with anteroventral margin greatly produced, anterodorsal margin with small rounded apodeme, margin between strongly concave; dorsomesal margin of segment strongly concave, very short, but continuously sclerotized; segment, in lateral view, short dorsally, posterior margin greatly, convexly produced between preanal appendages and small, subtriangular ventral process, inferior appendage mounted at midheight; anteroventral margin of segment, in dorsal or ventral views, with lateral margins converging, mesal margin with weak concave emargination. Lateral lobes of tergum X elongate, parallel sided, tapering apically, simple in structure, lateral margin with ~ 10 unraised sensilla scattered along its length; mesal lobe of tergum X very short, membranous, much shorter than lateral lobes. Preanal appendages short and knob-like, distinctly constricted basally. Inferior appendage moderately elongate, projecting, without significant basal inflection, dorsal and ventral margins subparallel, with narrow, digitate, posteriorly projecting process at approximately midlength from dorsal margin, length of inferior appendage slightly> 2 × its width, apex narrowing, rounded. Phallic apparatus with phallobase very elongate and narrowly tubular, with pair of very elongate, narrow sclerites, wider at midlength (possibly modified lateral sclerites of phallotremal sclerite complex), positioned apical to a more or less typical and moderately elongate rod and ring structure of phallotremal sclerite complex.

Etymology.

Chimarra multisensillata , name used as an adjective, for the relatively numerous sensilla on the lateral lobes of tergum X, a very unusual characteristic for a species in the Chimarrha marginata Group.

Figures

Figure 36. Chimarra multisensillata sp. nov., ♂ genitalia A lateral B dorsal, segments IX and X C inferior appendage, ventral D inferior appendage, dorsal E phallus, lateral F phallus, dorsal.