Chimarra agumatsa, 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 agumatsa sp. nov.

Fig. 55A-F

Type material.

Holotype. Ghana - Volta Reg. ● ♂ (in alcohol); Wli, Agumatsa waterfall, station # 2B; 7°07'29"N, 0°35'31"E; 5-8 Mar. 1993; JS Amakye & J Kjærandsen leg.; Malaise trap; UMSP 000550055. Paratypes. Ghana - Volta Reg. ● 2♂♂; same data as for holotype except 8-11 Mar. 1993; ZMBN ● 6♂♂; same data as for holotype except station # 1B; 5-14 Mar. 1993; ZMBN ● 2♂♂; same data as for holotype except station # 5C; 6-9 Mar. 1993; ZMBN ● 1♂; same data as for holotype except station # 6; 11-20 Nov. 1993; J Kjærandsen leg.; ZMBN.

Additional material.

Ghana - Volta Reg. ● 1♀ Wli, Agumatsa waterfall, station # 6; 7°07'29"N, 0°35'31"E; 11-20 Nov. 1993; J Kjærandsen leg.; Malaise trap; ZMBN ● 1♀; same collection data as for preceding; UMSP .

Diagnosis.

Chimarra agumatsa shows its relationship to species of the Chimarrha georgensis Group in having an elongate apical segment of its maxillary palps and in its primitive venation (straight Rs vein of the forewing, linear, unpigmented chord, and absence of a “fork” or crossvein in the anal veins). It would appear to have its greatest affinity to members of the Chimarrha georgensis subgroup, especially in having the phallobase relatively short, with its apex somewhat bifid. However, it is distinctive in a number of ways, including the absence of a tergum X, loss of fork III in the hind wing, and in having the phallus less sclerously anchored than is typical in members of the Chimarrha georgensis Group in general. For this reason, we have left the species unassigned to subgroup.

Chimarra agumatsa is easily diagnosed by the characters discussed above, in addition to the distinctive shape of its inferior appendages, which are very short, with both the ventral and dorsal margins incurved. It is apparently most similar to C. ino Marlier, whose inferior appendages have more or less the same structure but have the projections from the ventral margin more elongate and projecting. Both species lack fork III in the hind wing. The quality of the original illustration of C. ino make other characters difficult to compare.

Description.

Adult. Overall color (in alcohol) yellowish brown, vertex of head slightly darker, appendages yellowish. Head moderately elongate (postocular parietal nearly as long as diameter of eye). Palps elongate; maxillary palp with 1st segment very short (approximately as long as wide), 2nd segment relatively short (~ 3 × length of 1st), apex with cluster of ~ 8-10 stiff setae, 3rd segment elongate, almost 2 × length of 2nd, 4th segment short (slightly shorter than 2nd), 5th segment very elongate (nearly length of 3rd and 4th combined). Forewing length: male, 4.0-5.0 mm; female, 4.0 mm. Forewing forks I, II, III, and V present; hind wing with forks I, II and V. Forewing with R1 nearly straight, basal fork of discoidal cell slightly enlarged, evenly forked, length of cell ~ 2 × width, fork I subsessile, fork II sessile, r crossvein intersecting discoidal cell at past midlength, 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), forks I and II sessile, anal loop small. Forelegs with apical tibial spur short; male with modified tarsal claws, apical three segments of tarsi short and flattened, claws asymmetrical, outer one elongate and twisted.

Male genitalia. Segment VIII short, sternum without posteroventral projection. Segment IX, in lateral view, subtriangular, anteroventral and postroventral margins both moderately produced, strongly converging dorsally, dorsal margin obsolete, or nearly so, anterior margin without apodemes. Ventral process of segment greatly reduced, rounded, ventrally projecting, width at base greater than length. Tergum X apparently absent, but with narrow, converging lateral processes below preanal appendages, subtending phallus and fused apicomesally. Preanal appendages small and knob-like, rounded, slightly constricted basally, apparently fused to segment IX. Inferior appendage very short, with dorsal margin enrolled and rounded, as viewed laterally, forming a projecting cusp on the mesal surface; ventral margin of appendage projecting, acute, and mesally curved, forming short spine-like projection on mesal margin. Phallic apparatus with phallobase relatively short, not (or not evidently) anchored by sclerotized periphallic membrane; ventral apex of phallobase, as viewed laterally, projecting and acute, as viewed ventrally, weakly bifid apically; dorsal margin of phallobase, as viewed laterally, distinctly projecting, subequal in length to ventral projection, but with mesal margin forming an elongate, narrow, desclerotized strip over much of its length, as viewed dorsally; endotheca apparently short and simple in structure, with a pair of short, curved, symmetrically oriented phallic spines; phallotremal sclerite complex small and indistinct, composed of short rod and ring structure.

Etymology.

Chimarra agumatsa , the name considered a noun in apposition, for the name of the scenic waterfalls near which the holotype specimen was collected.

Figures

Figure 55. Chimarra agumatsa sp. nov., ♂ genitalia A lateral B caudal C inferior appendage, ventral D inferior appendage, dorsal E phallus, lateral, with ventral view of phallobase apex F phallus, dorsal.