Wormaldia imbrialis, Holzenthal, Ralph W., Blahnik, Roger J. & Rios-Touma, Blanca, 2018

Holzenthal, Ralph W., Blahnik, Roger J. & Rios-Touma, Blanca, 2018, New species and a new genus of Philopotamidae from the Andes of Bolivia and Ecuador (Insecta, Trichoptera), ZooKeys 780, pp. 89-108: 89

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scientific name

Wormaldia imbrialis

sp. n.

Wormaldia imbrialis   sp. n. Fig. 8, 9


This species is similar to W. prolixa   Flint, W. andrea   Muñoz-Quesada & Holzenthal, and W. gallardoi   Muñoz-Quesada & Holzenthal, a group of Neotropical Wormaldia   that was characterized by Muñoz-Quesada and Holzenthal (2015) as having segment IX strongly acute and projecting anterolaterally, the “head” of tergum X convexly subtriangular with its apex subtriangularly widened, and the apical segment of the inferior appendage longer than the basal segment. Wormaldia imbrialis   , new species, differs from this general character assessment in that segment IX is not strongly projecting anteriorly and the apical segment of the inferior appendage is shorter than the basal. Additionally, the new species differs from other species in the group in having a very long and slender phallic spine, while in the others it is very short and hooked.


Male. Forewing length 3.9 mm. Spur formula 2:4:4, foretibial spurs very short. Wing venation typical for Wormaldia   : forewing with forks I-V, forks I and II slightly subsessile, s, r-m, and m hyaline and linear, 3A looped to 2A and 2A to 1A, intersecting vein at about midlength, crossveins absent; hind wing with forks I-III and V (fork IV absent), 2A vein absent. General color pale yellowish brown, setae of head and thorax yellowish, with several dark brown setae on postparietal sclerite; palps and antennae darker, palps brown, antennae annulated, with brown setae basally, pale setae apically. Head very short, rounded, eyes conspicuous, with short setae between facets. Postparietal sclerite very short. Both sets of palps very short.

Genitalia. Segment VIII with tergum and sternum very narrowly separated, sternum with numerous short setae, tergum with scattered short setae on posterior half; as viewed laterally, with anterior margin nearly straight, posterior margin concave (conforming with contour of anterior margin of segment IX); as viewed dorsally, with shallow, crescentic posteromesal invagination, bordered laterally by very short spine-like projections and rounded lobes lateral to these. Segment IX synscleritous, dorsal and ventral margins invaginated anteromesally, dorsal margin very short (nearly obsolete), ventral margin about as long as sternum VIII; as viewed laterally, with anterolateral margin broadly rounded, not acutely projecting, posterior margin nearly straight. Tergum X very long, narrow, apex capitate, somewhat recurved dorsally, apex with scattered small sensilla; recurved apical projection acute as viewed laterally, rounded as viewed dorsally; apex of tergum continuous with rod-like mesal ridge, extending nearly to base; basal margins of tergum with rounded (or subangular) lateral projections as viewed dorsally, each with scattered small sensilla. Preanal appendages relatively elongate, digitate, somewhat curved basally (as viewed dorsally). Inferior appendages with basal segment elongate and wide, extending beyond tergum X; apical segment ca. ⅔ length of basal segment and much narrower, tapering apically, apex rounded, mesal surface with short, thick, spine-like setae, extending for ca. apical ⅔ of segment. Phallic apparatus proportionately very large, phallobase with greatly inflated basodorsal projection, narrowing apically; internally with very elongate, narrow spine, apex of spine acuminate.

Female. Unknown.


Male. ECUADOR: Pichincha: Amagusa Reserve (private), Río Mashpi Chico “alto”, 00.15487°N, 78.85316°W, 1180 m, 17.i.2015, Holzenthal, Huisman, Ríos-Touma (UMSP000146946) ( UMSP).


From the Latin imbrialis   , meaning "of rain" and referring to the night of the collection when a huge downpour occurred after the species was captured.


Despite the variation of W. imbrialis   , from others in the prolixa   group listed above and defined by Muñoz-Quesada and Holzenthal (2015), we note additional characters that indicate its probable inclusion in the group. All four species have similarities of tergum X and also similarities in the apical segment of the inferior appendage, including both its shape and accompanying elongate patch of short, spine-like setae. Also, each of these species has the dorsum of segment VIII with a shallow, crescentic, posteromesal invagination, bordered laterally by very short to short spine-like or thumb-like projections.

New record

Chimarrhodella peruviana   ( Ross) 1956 1956:69 [Type locality: Perú, Cusco, Paucartambo, Cosnipata Valley; INHS; ♂; in Protarra   ]. - Flint 1991:25 [♂; distribution]. - Blahnik and Holzenthal 1992:121 [♂; ♀; distribution]. - Flint 1996:385 [distribution]. - Muñoz-Quesada 2000:280 [checklist].

New records. ECUADOR: Morona-Santiago: tributary to Río Abanico, Hwy E46 (via Río Bamba-Macas), 2.24985°S, 78.20238°W, el. 1531 m, 12.xi.2015, Ríos-Touma, Thomson, Amigo, 2 males, 2 females ( UMSP). Sucumbios: Reserva Municipal La Bonita, road from La Bonita to La Sofia, 0.343278°N, 77.6443721°W, el. 1416 m, 16.xi.2017, Thomson, Ríos-Touma, Amigo, 1 female ( UMSP); road from La Bonita to Umpaqui, Río Seco, 0.471334°N, 77.558069°W, el. 1777 m, 17.xi.2017, Thomson, Ríos-Touma, Amigo, 1 female ( UMSP).

Distribution. Colombia, Ecuador, Perú, Venezuela.