Costatrichia inaequalis,

Neto, Jaime De Liege Gama, Ribeiro, José Moacir Ferreira & Passos, Mahedy Araujo Bastos, 2019, Two new species of Hydroptilidae (Insecta: Trichoptera) from the Serra dos Carajás, Pará state, northern Brazil, Zootaxa 4695 (4), pp. 385-390: 386-388

publication ID

publication LSID

persistent identifier

treatment provided by


scientific name

Costatrichia inaequalis

sp. nov.

Costatrichia inaequalis  sp. nov.

Figs. 2View FIGURE 2 A–2D

Diagnosis. This species belongs to the Costatrichia simplex  Species Group of Flint (1970). Males of Costatrichia inaequalis  sp. nov. are very distinctive, with little similarity to any other known species in the genus, despite the fact that it is diagnosed as Costatrichia simplex Flint 1970  in the key by Holzenthal & Harris (1999). However, those two species can be easily distinguished by the shape of the posteromesal process of segment VII and inferior appendages in lateral view. In the new species the posteromesal process of segment VII is like a keel and the inferior appendages are short and apically round whereas in C. simplex  the posteromesal process of segment VII is bifid, and the inferior appendages are rectanguloid. Additionally, in the new species the lateral processes on tergum IX and the subgenital plate are present (both absent in C. simplex  ).

Description. Male. Head with black setae. Antenna unmodified, each with 38 segments, terete. Three ocelli. Forewings black, each 2.12–2.37 mm long (n = 10, holotype and paratypes), narrow transverse whitish stripe at midlength, basal costal bulla absent ( Fig. 2AView FIGURE 2). Tibial spur formula 1,3,4. Abdominal sternum VII bearing apicomesal keel-like process ( Fig. 2BView FIGURE 2).

Male genitalia. Sternum VIII, in lateral view, rectangular, anterior margin slightly concave, posterior margin rounded ( Fig. 2CView FIGURE 2). Segment IX annular, deeply concave anteroventrally in ventral view, ventral half covered by posterior border of sternum VIII; posterolateral processes of segment IX, in lateral view, rounded, each bearing long anterodorsal seta, hooked mesoventrad to acute apex ( Figs. 2C, 2DView FIGURE 2). Segment X medially membranous, subquad- rate in dorsal view, dorsolateral margins sclerotized, each ending in hooked apex directed laterad ( Figs. 2C, 2DView FIGURE 2). Subgenital plate triangular, slightly sclerotized, anterior margin medially excised in both dorsal and ventral views, posterior margin medially acute and sclerotized ( Figs. 2D, 2EView FIGURE 2); in lateral view, hooked ventrad to acute and sclerotized apex ( Fig. 2CView FIGURE 2). Inferior appendages, in lateral view, short and apically round; in ventral view, wider than long ( Figs. 2C, EView FIGURE 2). Phallus with basal tubular portion and midlength complex bearing dorsolateral windows and basal loop ( Fig. 2FView FIGURE 2); apically membranous, with long and tubular sclerite dorsobasally open, distally narrowing to acute apex ( Figs. 2F, 2GView FIGURE 2).

Female, pupa, larva, and egg: Unknown.

Holotype male. BRAZIL: Pará : Parauapebas municipality, Serra dos Carajás, low order stream, 6°2’24.828”S, 50°17’38.184”W, 7–9 Aug. 2018. Pennsylvania light trap, J.L. Gama Neto & M.J. Ferreira Ribeiro, cols. (alcohol; MPEG).GoogleMaps 

Paratype. 10 males, same data as holotype (alcohol; 5 MPEG, 5 INPA)GoogleMaps  .

Distribution: Brazil (Pará State).

Etymology. The term “inaequalis” refers to the distant dissimilarity of this species from any other known species in the genus.


Museu Paraense Emilio Goeldi


Instituto Nacional de Pesquisas da Amazonia