Sumacodella elongata, 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

Sumacodella elongata sp. nov.

Figs 3 , 4 , 5

Type material.

Holotype. Male (pinned). Ecuador: Napo: Wildsumaco Lodge, small stream, Coati Trail @ wooden bridge, 0.67433°S, 77.60260°W, 1420 m a.s.l., 10.iii.2020, Ríos, Holzenthal, Frandsen, Pauls, Amigo, UMSP000500637 (UMSP). Paratypes. Ecuador: same data as holotype, 2 males (pinned) (UMSP), 1 male, 1 female (pinned) (MECN).

Diagnosis.

This new species is not easily placed in any established genus of Philopotaminae and consequently we are placing it in a new genus. Like other taxa that Ross (1956) assigned to Sortosa Navás, 1918 (subsequently reassigned to Dolophilodes Ulmer, 1909) it has the plesiomorphic trait of retaining all three anal veins in the hind wing. A character suggesting its possible relationship to the genus Alterosa , currently only known from eastern and southern Brazil, is the structure of the phallobase, which is uniformly tubular and lacks the basodorsal expansion typical of most genera of Philopotamidae . Also, like Alterosa , it lacks a ventral process on any of its abdominal segments, but, unlike Alterosa , it lacks a pair of intermediate appendages mesal to the preanal appendages, which was used as an apomorphic and defining character for that genus by Blahnik (2005). However, Dumas and Nessimian (2013) described two Brazilian species, A. graciosa and A. inappendiculata , that lack intermediate appendages, but otherwise these species conform morphologically to other species in the genus. Sumacodella elongata , in other features, is not similar to those two species and possesses several unique and unusual characters, which collectively serve as the basis for a generic diagnosis.

Characters of Sumacodella that can generally be regarded as plesiomorphic for Philopotaminae , as indicated by Ross (1956), include the venation of the forewing, which has a complete set of forks (I, II, III, IV, and V), a more or less linear and hyaline chord, composed of the s, r-m, and m crossveins, and looped anal veins, which converge basally and lack a crossvein, leaving a long common vein extending to the arculus (Fig. 4A ). The hind wing has all three anal veins reaching the wing margin (Fig. 4B ), a plesiomorphic character within Philopotaminae , also discussed by Ross (1956), and lacks fork IV, a character loss generally considered synapomorphic for the entire family Philopotamidae , exclusive of Rossodes tsaratananae (Ross, 1956). Sumacodella elongata has also lost fork III in the hind wing, probably convergently with several other taxa in the family, including some species of Wormaldia and some Chimarra . Also, plesiomorphic for Philopotaminae are the bi-segmented inferior appendages, each with an apicomesal pad of short spine-like setae (Fig. 3A ), the elongate, digitate preanal appendages (Fig. 3A, B ), and setation of the tergal segments anterior to segment IX, in which at least some segments have a pair of desclerotized patches near the posterior margin with several elongate setae, but the setation is otherwise confined to short and often sparse setae near the posterior margin. Distinctive characters for Sumacodella elongata , likely to be apomorphic because of their uniqueness within the family Philopotamidae , include an elongate and tapering segment IX (Fig. 3A ), with an elongate ventral margin, but with the posterior margin nearly linearly narrowing dorsally, so that the posterior margin converges with the anterior margin dorsomesally, and from which the narrow, digitate preanal appendages emerge, as well as the base of tergum X. The very elongate, narrow anterolateral apodemes of segment IX are unique within Philopotamidae (Fig. 3A ). Also unique within Philopotamidae is the very elongate and narrow tergum X, with sensilla confined to a narrow apicomesal projection, bordered by narrow lateral projections in the distal 3rd of the segment (Fig. 3A, B ). Other characters unique to Sumacodella include the very elongate anteromesal apodeme of the inferior appendages (Fig. 3C, D ) and the very elongate, tubular phallus, which is tubular anteriorly, rather than with a basodorsal projection, and has tracts of small, included spines (Fig. 3E, F ). All these characters are diagnostic for the type species of the genus and any of them would serve as diagnostic characters for placement of additional species within the genus.

Description.

Adult. Forewing length male 5.0-5.7 mm (n = 4); female 5.9 mm (n = 1). Head short, rounded; postocular parietal sclerite less than half diameter of eye. Overall color dark brown, including palps and antennae; head and base of forewing with longer, light brown setae, femora slightly paler, antennae with narrow annulations at intersection of segments, chord of forewing only indistinctly evident. Wings both relatively broad and rounded apically. Forewing with forks I, II, III, IV, and V; with chord nearly linear and hyaline (lacking pigmentation), anal loops of forewing with both 2A and 3A intersecting 1A in basal half of vein, 3A nearly convergent with 2A. Hind wing with forks I, II, and V, with all three anal veins reaching wing margin. Spur formula 2:4:4, spurs of foretibiae both short, outer spurs of mesotibiae slightly greater than half length of inner spurs, spurs of metatibia both elongate, outer spurs slightly shorter. Foretarsi of males unmodified, narrow.

Male. Segment VIII moderately elongate, sternum and tergum subequal in length, sternum densely covered with short, fine setae, tergum with setae confined to posterior region of segment, posterodorsally with pair of desclerotized patches with several more elongate setae (characteristic of most species in subfamily Philopotaminae ). Segment IX, in lateral view, synscleritous, elongate, strongly tapering, with pair of very elongate apodemes on anterolateral margin at ca. mid-height, ventral margin strongly produced posteriorly, subtruncate as viewed dorsally or ventrally, posterior margin very obliquely narrowed dorsally, with lateral margin converging from ca. mid-height to anterior margin; as viewed dorsally, with posterior margin forming V-shaped convergence at anterior margin. Tergum X very elongate, narrow, and parallel-sided, weakly arched as viewed laterally, base distinctly narrowed at mesal juncture of anterior and posterior margins of segment IX, forming short tab-like projection; in apical 3rd or 4th forming elongate, narrow mesal lobe, bordered by pair of elongate, narrow lateral lobes, slightly shorter than mesal lobe; mesal lobe densely covered with sensilla, basally with pair of short, stalked projections at juncture with lateral lobes, each with one or two short terminal setae. Preanal appendage elongate, narrow, proximate basally, at juncture of tergum X and anterior and posterior convergence of dorsal margins of segment IX, appendage very narrow basally, gradually widening apically. Inferior appendage bi-segmented, segments subequal in length, nearly uniform in width; apical segment rounded, with dense pad of short, stiff apical spines, somewhat extended anteriorly on ventromesal surface. Phallus very elongate, narrow, tubular, without basodorsal projection; internally with several patches of fine, nail-like spines, varying in length, apical patch (in incompletely everted endotheca) preceded by two more elongate spines. Phallotremal sclerite very indistinct, weakly sclerotized, small, and ring-like.

Female. Genitalia very elongate, tapering from segment VII. Segment VII elongate, sternum covered with fine setae; tergum with setae confined to posterior half. Segment VIII with tergum and sternum not fused, shorter than segment VII, relatively undifferentiated in structure and shape, together forming narrow tube; sternum with very elongate, narrow apodemes from dorsolateral margins, at ca. mid-length, extending to ca. mid-length of segment VII. Segment IX shorter and somewhat narrower than segment VIII, sternum and tergum apparently divided, at least anteriorly, segment with very elongate, narrow apodemes, extending to ca. base of segment VIII. Segment X composed of pair of elongate, bulbous lobes, each lobe with short setae basally, apically with numerous sensilla and small, digitate cercus.

Etymology.

The genus is named Sumacodella , feminine, for Volcán Sumaco, an isolated stratovolcano located in the Ecuadorian Amazon, which hosts an amazingly high diversity of endemic plants and animals. The termination - della is intended to make the name euphonious with Chimarrhodella , Hydrobiosella , and Aymaradella , other philopotamids known from the Neotropics. The specific epithet is from the Latin elongatus, meaning elongated and referring to the several elongate appendages and other structures of the male genitalia, which are very diagnostic for this new species.

Figures

Figure 3. Sumacodella elongata gen. nov., sp. nov. Male genitalia A segments VIII-X, lateral B segments VIII-X, dorsal C inferior appendage, dorsal D inferior appendage, ventral E phallus, dorsal F phallus, lateral.

Figures 4, 5. Sumacodella elongata gen. nov., sp. nov. Male wings and female genitalia 4 A forewing 4 B hind wing 5 female genitalia, segment VII-X, lateral.