Costatrichia inaequalis, Neto & Ribeiro & Passos, 2019

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

Costatrichia inaequalis sp. nov.

Figs. 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. 2A ). Tibial spur formula 1,3,4. Abdominal sternum VII bearing apicomesal keel-like process ( Fig. 2B ).

Male genitalia. Sternum VIII, in lateral view, rectangular, anterior margin slightly concave, posterior margin rounded ( Fig. 2C ). 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, 2D ). Segment X medially membranous, subquad- rate in dorsal view, dorsolateral margins sclerotized, each ending in hooked apex directed laterad ( Figs. 2C, 2D ). Subgenital plate triangular, slightly sclerotized, anterior margin medially excised in both dorsal and ventral views, posterior margin medially acute and sclerotized ( Figs. 2D, 2E ); in lateral view, hooked ventrad to acute and sclerotized apex ( Fig. 2C ). Inferior appendages, in lateral view, short and apically round; in ventral view, wider than long ( Figs. 2C, E ). Phallus with basal tubular portion and midlength complex bearing dorsolateral windows and basal loop ( Fig. 2F ); apically membranous, with long and tubular sclerite dorsobasally open, distally narrowing to acute apex ( Figs. 2F, 2G ).

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).

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

Distribution: Brazil (Pará State).

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

Figures

FIGURE 2. Costatrichia inaequalis sp. nov. 2A, forewing (upper) and hind wing (lower). 2B, VII sternal process, left lateral. 2C–2G, male genitalia: 2C, left lateral; 2D, dorsal; 2E, ventral; 2F, phallus, left lateral; 2G, phallus, dorsal.