Chimarra kjaerandseni, 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

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scientific name

Chimarra kjaerandseni

sp. nov.

Chimarra kjaerandseni sp. nov.

Fig. 56A-G View Figure 56

Type material.

Holotype Ghana - Volta Reg. ● ♂ (in alcohol); Wli, Agumatsa waterfall, station # 5C; 7°07'29"N, 0°35'31"E; 9-12 Mar. 1993; JS Amakye & J Kjærandsen leg.; Malaise trap; UMSP 000550057.

Additional material.

Ghana - Volta Reg. ● 1♀; Wli, Agumatsa waterfall, station # 6; 7°07'29"N, 0°35'31"E; 20 Nov. 1993; J Kjærandsen leg.; light trap; UMSP GoogleMaps .


Chimarra kjaerandseni is a unique and enigmatic species, very different from the other species placed in the Chimarrha georgensis Group, but sharing some of the diagnostic characters, including a maxillary palp with a relatively elongate terminal segment and primitive venational characters, including a forewing with a straight Rs vein, a linear, unpigmented chord, and absence of a “fork” or crossvein in the anal veins. Like the species in the Chimarrha evoluta subgroup, it lacks fork I and III in the hind wing. However, none of the genitalic characters are particularly suggestive of a relationship with this subgroup, since it lacks either the elongate processes from the dorsal margin of segment IX or modified ventral apex of the phallobase that characterize other species in the subgroup. Because of this, and despite the very suggestive hind wing venational loss characters, we prefer to consider this species unassigned to subgroup in the Chimarrha georgensis Group.

General diagnostic characters of the species include the general shape of segment IX, which is relatively elongate and lacks anterodorsal apodemes, the ventrally projecting ventral process of the same segment, the simple lateral lobes of tergum X, and the short curved inferior appendages. Additionally, the numerous small spines in the phallus, its relative length, absence of a projecting ventral apex on the phallobase, as well as the relatively desclerotized posteromesal margin of segment VIII are also all useful diagnostic characters, not found in any other species of the Chimarrha georgensis Group.


Adult. Overall color (in alcohol) yellowish brown, vertex of head slightly darker, appendages yellowish. Head relatively short (postocular parietal sclerite ~ 1/2 length of eye). Palps relatively elongate; maxillary palp with 1st segment short and stout (approximately as long as wide), 2nd segment moderately elongate (~ 3 × 1st), apex with cluster of 6-8 stiff setae, 3rd segment slightly longer than 2nd, 4th segment short (~ 1/2 length of 3rd), 5th segment relatively elongate and very narrow (somewhat shorter than 3rd and 4th combined). Forewing length: male, 4.0 mm. Forewing with forks I, II, III, and V present; hind wing with forks II and V only. Forewing with Rs straight, or nearly so, basal fork of discoidal cell slightly enlarged, evenly forked, length of cell ~ 2 × width, fork I subsessile, II sessile, r crossvein not evident, s, r-m, and m crossveins linear and hyaline, both 2A and 3A looped to 1A (2A without apical fork). Hind wing with R1 obsolete (or fused to subcosta), fork II slightly subsessile, anal loop small. Forelegs with apical tibial spur very short; male with modified tarsal claws, apical tarsal segment enlarged and flattened, claws asymmetrical, outer one elongate and slightly twisted.

Male genitalia. Segment VIII short, sternum without posteroventral projection, tergum slightly longer, with very distinct membranous posteromesal invagination. Segment IX, in lateral view, relatively elongate ventrally, anteroventral margin moderately expanded, posterior margin subparallel to anterior margin to point just above inferior appendage, then angularly narrowing dorsally; as viewed dorsally, with dorsal margin short, but continuous, anteroventral margin subtruncate. Ventral process of segment IX ventrally projecting, subtriangular, closer to anterior than posterior margin. Lateral lobes of tergum short and broad, subparallel, widely separated dorsally, with membranous lobe between, lobes converging anteroventrally, apices of lobes each with angular, beak-like, ventral projection, sensilla absent or indistinct. Preanal appendages prominent, rounded and knob-like, slightly constricted basally, apparently fused to segment IX. Inferior appendage, as viewed laterally, short and simple in shape, distinctly inflected basally, longer than wide, slightly tapering, apex rounded, mesally curved as viewed dorsally or ventrally, without cusp or tooth on mesal margin. Phallic apparatus with phallobase moderately elongate, tubular, without distinctly sclerotized periphallic membrane, ventral apex of phallobase not projecting. Endotheca at least moderately elongate, textured with small spine-like projections and several clusters of short spines, phallotremal sclerite complex small and indistinct, forming short rod and ring structure.


We are pleased to name this species for Jostein Kjærandsen, who participated in the collecting expedition that generated much of the material that the current study is based on, in addition to doing an initial sorting of the material and initiating the study.