Chimarra (Chimarra) pacifica, Holzenthal & Blahnik & Ríos-Touma, 2022

Holzenthal, Ralph W., Blahnik, Roger J. & Rios-Touma, Blanca, 2022, A new genus and new species of Ecuadorian Philopotamidae (Trichoptera), ZooKeys 1117, pp. 95-122 : 95

Chimarra (Chimarra) pacifica sp. nov.

Fig. 10

Type material.

Holotype. Male (pinned). Ecuador: Pichincha: San José de Mashpi, Río Mashpi, 0.18954°N, 78.92117°W, 498 m a.s.l., 8.iii.2020, Ríos, Holzenthal, Frandsen, Amigo, UMSP000500813 (UMSP). Paratype. Ecuador: El Oro: 9 mi. S Santa Rosa [3.581°S, 79.932°W, uncertainty 13,558 m], 23.i.1955, E.I. Schlinger & E.S. Ross, 1 male (in alcohol) (CAS).

Diagnosis.

Chimarra pacifica is a new species in the Chimarra (Chimarra) beameri group of Blahnik (1998), very similar to both C. munozi Blahnik & Holzenthal, 1992 and C. dudosa Blahnik, 1998, resembling them in the general shape of the inferior appendages and spatulate lateral lobes of tergum X, and also in having an array of short spines associated with the phallotremal sclerite complex (Fig. 10E ). It differs in that the apex of the inferior appendage has a short, but distinctive, protuberance from its ventral margin (Fig. 10A ). Tergum X is also less strongly deflexed than in either of the compared species (Fig. 10A ). The only other species of the Chimarra beameri group currently reported from Ecuador is C. coheni Blahnik, 1998, which also has spatulate lateral lobes of tergum X, but differs in having a distinctly bifid apex of its inferior appendage and much longer phallic spines. The species also seems to lack the array of short spines associated with the phallotremal sclerite complex seen in the new species, but these are easily overlooked in specimens in which the endotheca is not everted.

Description.

Adult. Forewing length male 4.0-4.3 mm (n = 2). Color nearly uniformly brownish black (fuscous), except femora yellowish brown and head somewhat darker, with scattered whitish setae on vertex and anteromesal setal wart. Head relatively short and rounded, postocular parietal sclerite short (less than half diameter of eye). Second segment of maxillary palp stout and elongate, subequal to 3rd, with stout apicomesal bristles, 5th segment shorter than 3rd. Male protarsal claws enlarged, asymmetrical in size and shape, outer claw longer and twisted.

Male. Abdominal segment IX, in lateral view, with well-developed anterodorsal apodemes, anteroventral margin distinctly extended, nearly linearly narrowing to dorsal apodemes, posterior margin weakly convex. Posteroventral process subtriangular, very large and prominent, length subequal to width at base. Tergum X membranous mesally, with sclerotized lateral lobes; lateral lobes, as viewed dorsally, spatulate in apical half, with two widely spaced sensilla near dorsal margin; as viewed laterally, turned down, with lateral crease in apical half. Preanal appendage short, rounded, knob-like, somewhat flattened as viewed dorsally. Inferior appendage, in lateral view, with rounded basal part and relatively narrow, moderately elongate; basal expansion weakly rounded to subtruncate, dorsal lobe with small tooth-like projection apicoventrally. Phallobase tubular, with basodorsal expansion, apicoventral margin only weakly projecting, two phallic spines, moderately elongate, subequal in length, endotheca apparently elongate, with small echinate spines. Phallotremal sclerite complex composed of rod and ring structure, rod short and curved and ring with prominent apicodorsal extension; apically with membranous structure subtending rod, anterior margin forming pair of weakly sclerotized, fishhook-like sclerites.

Female. Unknown.

Etymology.

This new species is named " Chimarra pacifica ," referring to the localities where the species was collected, both on the Pacific slope of the Ecuadorian Andes.

Habitat notes.

Río Mashpi is a clear water river with base flow ~ 4 m3/s and with peak flows between March to May. Conductivity is low, ranging from 46-58.5 µS /cm, oxygen is close to 100% saturation, and daytime water temperature ranges from 20-23 °C year-round.

Figures

Figure 10. Chimarra (Chimarra) pacifica sp. nov. Male genitalia A segments IX, X, lateral B segments IX, X, dorsal C inferior appendages, oblique lateral D inferior appendage, ventral E phallus, lateral.