Metrichia riosi, Armitage & Harris & Rodriguez, 2025

Armitage, Brian J., Harris, Steven C. & Rodriguez, Viterbo, 2025, The Trichoptera of Panama XXVIII. Nine new species of microcaddisflies (Trichoptera, Hydroptilidae), Neotropical Biology and Conservation 20 (2), pp. 125-147 : 125-147

Metrichia riosi sp. nov.

Fig. 8

Type locality.

Panama: Veraguas Province, Soná District, Canales de Afuera Island off the Soná Peninsula nr. Pixvae; 7.69494°N, 81.62649°W; 29 m a. s. l.

Type specimen.

Holotype • ♂, in alcohol. Original label: Panama: Veraguas Province, Soná District, Canales de Afuera Island off the Soná Peninsula nr. Pixvae ; 7.69494°N, 81.62649°W; 29 m a. s. l.; 6–22 Mar 2023; leg V. Rodriguez; Malaise trap ”; MUPADI . Paratypes • 5 ♂♂, in alcohol; same as holotype; MUPADI .

Diagnosis.

Metrichia riosi sp. nov. is similar to M. trebeki Harris & Armitage , M. rawlinsi Flint & Sykora and M. triquetra Bueno-Soria & Holzenthal , based on the shape of inferior appendage in lateral view, but it differs from these species in the structure of the phallus, which has three subapical spines.

Description.

Male. Total length 2.1–2.3 mm (n = 6), 18 antennal segments, wings and body brown in alcohol. G enitalia (Fig. 8 ). Abdominal segment VII annular, without ventromesal process. Segment VIII in lateral view, triangular, tapering ventrad; in dorsal view, annular; in ventral view, deeply incised mesally. Segment IX in lateral view, truncate posteriorly, narrowing anteriorly and extending into segment VII, incomplete dorsally; in dorsal view, reduced to a narrow band, lateral margins sclerotised, rounded anteriorly; in ventral view, truncate posteriorly, lateral margins sclerotised, rounded anteriorly. Segment X in lateral view, shelf-like, rounded distally; in dorsal view, thinly rectangular, rounded apically. Pre-anal appendage (cercus) narrowly rounded in lateral view; in dorsal view, circular; dorsolateral hook in lateral view elongate, thin and tapering distally; in dorsal view, widening distally with apex incised, extending beyond inferior appendages. Inferior appendage in lateral view circular basally, narrowing ventrally and tapering to thin acute apex; in dorsal and ventral views, divided apically into pair of lobes, sclerotised in outer margin. Phallus elongate, wide basally then narrow over length, three elongate spines subapically, ejaculatory duct sclerotised over length.

Female and immature stages.

Unknown.

Etymology.

Named for Tomás A. Ríos González, Panamanian biologist at the Museo de Peces de Agua Dulce e Invertebrados of the Universidad Autónoma de Chiriquí in recognition of his intensive and extensive involvement with our studies of aquatic insects in Panama. The name is a noun in the genitive case.

Figures

Figure 8. Metrichia ríosi sp. nov., male holotype, genitalia A left lateral B dorsal C ventral D phallus, dorsal E phallus apex, lateral.