Chimarra fallax (Ulmer, 1912)

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 fallax (Ulmer, 1912)

Fig. 10A-E

Wormaldia fallax Ulmer, 1912: 84-85, figs 5-8a.

Chimarrha fallax (Ulmer): Marlier 1959 (distribution: Sao Tomé); Fischer 1961: 59; Fischer 1971: 210.

Chimarra lukawei Jacquemart, 1961a: 40, fig. 27a. Syn. nov.

Chimarra lukawei Jacquemart: Jacquemart, 1961b: 230; Jacquemart 1966a: 49, fig. 14A-B; Wahlberg and Johanson 2014: 437-439, figs 1-3; Gibon 2018: 123-124, figs 1B, 3B-D, 5 (distribution: Madagascar).

Chimarra lukawaei [sic] Jacquemart: Morse 2021 [also, many online taxonomic resources using the Trichoptera World Checklist as a source].

Chimarra sp. AK: Gibon & Elouard, 1996: 510.

Material examined.

Ghana - Central Reg. ● 28♂♂ 41♀♀; Kakum Forest Reserve; 5°21'N, 1°22'W; 8-15 Nov. 1994; T Andersen leg. ; Malaise trap; ZMBN ● 1♂ 1♀; same collection data as for preceding; UMSP. - Western Reg. ● 5♀♀; 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 ; light trap; ZMBN.

Diagnosis.

Inferior appendage short and rounded apically; phallobase with ventral apex short and only weakly projecting, not enlarged apically; phallic spines both relatively elongate and narrow, differing in length; periphallic processes fused mesally, comparatively narrow and weakly developed; posteroventral margin of sternum VIII distinctly projecting.

Within the Chimarrha fallax subgroup, the distinguishing feature of this species is the relatively short inferior appendages with apices that appear rounded in lateral view. The only evident difference in the illustrations provided for C. fallax and that of C. lukawei is the more prominent dorsal spine-like projections of tergum X in C. fallax . The difference is minor, and we do not consider it to be of species-level significance.

Within the group of taxa assigned to the Chimarrha fallax subgroup with a spine-like modification to the lateral lobes of tergum X, it is the only species in which the ventral apex of the phallobase is weakly or only moderately projecting; the periphallic processes are also much less developed than in the other species. Thus, it probably represents a basal species of this clade.

Redescription.

Adult. Overall color (in alcohol) yellowish brown, appendages slightly paler. Head relatively short (postocular parietal sclerite <1/2 diameter of eye). Palps relatively short; maxillary palp with 1st segment very short (approximately as long as wide), 2nd segment moderately elongate, apex with small cluster of stiff setae, 3rd segment subequal to segment 2, 4th segment short (~ ½ length of segment 2), 5th segment subequal to 2nd or 3rd. Forewing length: male, 5.0-6.0 mm; female 5.5-6.5 mm. Fore- and hind wings with forks I, II, III, and V present. Forewing with R1 very sinuous, stem of Rs inflected at past midlength (with distinct small node at inflection), basal fork of discoidal cell distinctly enlarged, fork asymmetric, length of cell ~ 2 × width, forks I and II both subsessile, r crossvein diagonal, intersecting discoidal cell at past midlength, s and r-m, crossveins linear, m crossvein more proximal, s pigmented (like wing), r-m and m crossveins hyaline, 2A with crossvein (apparently forked apically to 1A and 3A). Hind wing with R1 reduced, but evident, narrowly parallel to subcosta, forks I and II strongly subsessile, fork III distal and relatively wide, anal loop small. Forelegs with apical tibial spur short; male with tarsal claws unmodified, apical segments of tarsi narrow, claws small and symmetrical.

Male genitalia. Segment VIII with sternum relatively short, ventrally with distinct projection from posterior margin, tergum slightly longer, expanded dorsally. Segment IX, in lateral view, with anteroventral margin weakly produced, anterior margin with angular inflection in ventral ¼, weakly concave and narrowing dorsally; tergum short dorsolaterally, with short, rounded apodemes, obsolete mesally between apodemes; posterior margin nearly linear; ventral margin sloping, more or less linear, with inferior appendages mounted high on segment (nearly midlaterally), basally with elongate, narrow ventral process near base, apex of process acute as viewed laterally, rounded as viewed ventrally, apicoventral surface of ventral process roughened and file-like; anterior margin of sternum subtruncate as viewed dorsally or ventrally. Lateral lobes of tergum X formed into short, narrow, sclerotized, dorsolaterally curved spine-like processes; dorsum of tergum X relatively short, membranous; tergum ventrally with relatively narrow, projecting, mesally fused, sclerotized, periphallic process, subtending phallic apparatus. Preanal appendages short and knob-like, distinctly flattened, membranous basally, but fused laterally to periphallic process. Inferior appendage relatively short, with pronounced basal inflection, apex dorsally inflected, broadly rounded, cupped (concave on mesal surface); as viewed ventrally, with weakly sclerotized projections near base and before midlength (projections not evident in lateral view); mesal surface without projections or ridges. Phallic apparatus with phallobase tubular, with usual basodorsal expansion, apicoventral margin not, or only weakly, projecting; endotheca with two asymmetrically positioned spines of moderate length, membrane textured with small spines, phallotremal sclerite complex composed of short rod and ring structure, with small preapical sclerite.

Distribution.

Cameroon, Democratic Republic of the Congo, Ghana, Madagascar, Sao Tomé.

Figures

Figure 10. Chimarra fallax (Ulmer), ♂ genitalia A lateral B dorsal, segments IX and X C inferior appendage, dorsal D segment IX and inferior appendages, ventral E phallus, lateral.