Rhyacopsyche Müller

Rhyacopsyche Müller, 1879a:40 [nomen nudum]; 1879b:143 [Type species: Rhyacopsyche hagenii Müller 1879 b, monobasic]; 1880a:121; 1880b:72. — Flint,1971:516 [definition, review].

Generic description. Adult. Forewing length 2.0– 4.9 mm; wings narrow, acuminate, mottled with light, medium, and/or dark brown hairs; forewing veins R1-R3, M1 and M2 thickened at apex, not reaching wing margin (Fig. 3); hind wing with long fringe of hairs along ventral margin. Unmodified head and antennae; 3 ocelli. Mesoscutellum with transverse suture; metascutellum usually pentagonal in shape (Fig. 2). Tibial spurs 1-3-4.

Male genitalia. Segment IX produced into dorsolateral lobes, often bearing 1 or more dark, peglike setae (Fig. 4 A). Tergum X weakly developed and often retracted partially (Fig. 9 A) or completely within segment IX (Fig. 4 A). Inferior appendage large and distinct, elongate (Fig. 7 A) or tall (Fig. 12 A), usually bearing 1 or more large modified setae. Intermediate appendage present, often reduced (Figs. 9 A, 9C). Phallus with tubular, frequently inflated basal half, apical half with central tubule and lateral process; often surrounded with a thin membranous sheath covered with spicules (Fig. 4 D).

Female genitalia. Simple oviscapt. Tergum VIII bearing a setate lobe (or lobes) from posterior margin (Fig. 5 B). Segments VII, VIII and IX with long internal rod-like apodemes (Fig. 5 A).

Larva. All 3 thoracic nota divided mesally (Fig. 1 C); legs stout and similar in structure, apex of tibia expanded bearing several enlarged setae; tarsus broad with 1 or 2 enlarged, platelike setae; claw basally inflated (Fig. 1 D). Abdominal segments IV–VII slightly swollen (Fig. 1 A); tergites absent; anal prolegs compressed to sides of segment X.

Larval case. Bivalve case elongate, tubular and fusiform; constructed of silk only or covered in sand grains; anterior end often with long, silken stalk used in attachment to the substrate (Fig. 1 E). Pupal case with oval anterior and posterior openings sealed with silk; when stalk is present, it is shortened and thickened for more rigid attachment to the substrate.