Published December 10, 2025 | Version v1
Taxonomic treatment Open

Rhyacopsyche tumida Thomson, Ríos-Touma & Holzenthal, 2025, sp. nov.

  • 1. Department of Entomology, University of Minnesota, 1980 Folwell Ave., St. Paul, MN, 55108, USA
  • 2. Grupo de Investigación en Biodiversidad, Medio Ambiente Ambiente y Salud (BIOMAS), Facultad de Ingenierías y Ciencias Aplicadas, Universidad de Las Américas, Quito CP 170503, Ecuador

Description

Rhyacopsyche tumida sp. nov.

Fig. 5

Type material. Holotype: Ecuador • ♂; Azuay, Rio Balao Grande in El Progreso [Sta. Isabel]; 02.90989°S, 079.59665°W; el. 213 m; 21 March 2022; Ríos, Holzenthal, Pauls, Frandsen, Thomson, Amigo leg.; in alcohol; UMSP 000280911; UMSP. Paratypes: Ecuador • 1 ♂; Azuay, Rio Chaucha & waterfall, 1.2 km E La Iberia; 02.89407°S, 079.50786°W; el. 700 m; 22 March 2022; Ríos, Pauls, Amigo leg.; in alcohol; UMSP 000418191; UMSP • 1 ♂; same as for preceding; UMSP 000418192; MECN.

Diagnosis.

This species most closely resembles R. turrialbe Flint, 1971, based on the overall form and appearance of abdominal segment IX and the inferior appendage. It can be most easily distinguished by the inferior appendage, which curves outward at the apex in R. tumida rather than curling inwards as in R. turrialbe.

Description.

Adult (male: n = 3). Forewing length 3.3–3.5 mm (male). Head unmodified, with 3 ocelli; antennae unmodified. Tibial spurs 1, 3, 4. Specimens brown in alcohol. Sternum VII with short mesoventral point. Male genitalia. Abdominal segment IX setose, anterolateral margin sinuate, posterolateral margin irregular with ventral projection; dorsolateral lobe of segment IX rounded with dark, peg-like setae, in dorsal view divided and rounded (Fig. 5 A, B). Tergum X membranous, retracted inside segment IX, with basal projections, articulating with intermediate appendage (Fig. 5 A, B). Intermediate appendage elongate, extending posteriad and bent dorsad, in lateral view apex curving slightly outward (Fig. 5 A, B). Inferior appendage wide, setose, divided into dorsal and ventral lobes; dorsal lobe with posterior margin produced into blunt process, dorsal margin bearing large, bulbous, peg-like seta; ventral lobe simple, broadly rounded (Fig. 5 A). Phallus basally tubular, elongate, apex membranous; central tubule with hooked apex; lateral process pointed (Fig. 5 D).

Etymology.

Tumidus, Latin for “ swollen, ” referring to the shape of the thick seta on the dorsal lobe of the inferior appendage.

Distribution.

Ecuador (Table 1).

Notes

Published as part of Thomson, Robin E., Ríos-Touma, Blanca & Holzenthal, Ralph W., 2025, Additions to the genus Rhyacopsyche Müller, 1879 (Trichoptera, Hydroptilidae) in Ecuador, pp. 531-543 in ZooKeys 1263 on pages 531-543, DOI: 10.3897/zookeys.1263.148084

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Linked records

Additional details

Biodiversity

Collection code
MECN , UMSP
Material sample ID
UMSP 000280911 , UMSP 000418191 , UMSP 000418192
Event date
2022-03-21 , 2022-03-22
Verbatim event date
2022-03-21 , 2022-03-22
Scientific name authorship
Thomson & Ríos-Touma & Holzenthal
Kingdom
Animalia
Phylum
Arthropoda
Order
Trichoptera
Family
Hydroptilidae
Genus
Rhyacopsyche
Species
tumida
Taxon rank
species
Taxonomic status
sp. nov.
Type status
holotype , paratype
Taxonomic concept label
Rhyacopsyche tumida Thomson, Ríos-Touma & Holzenthal, 2025

References

  • Flint Jr OS (1971) Studies of Neotropical caddis flies, XI: the genus Rhyacopsyche in Central America (Hydroptilidae). Proceedings of the Biological Society of Washington 83 (46): 515-526.