Metrichia bostrychion Thomson & Holzenthal

Thomson, Robin E. & Holzenthal, Ralph W., 2012, New species and records of Hydroptilidae (Trichoptera) from Venezuela, ZooKeys 185, pp. 19-39 : 21-22

Metrichia bostrychion Thomson & Holzenthal sp. n. Fig. 3

Diagnosis.

This species is most similar to Metrichia anisoscola (Flint, 1991), but differs in the shape of the inferior appendage, which is less elongate in Metrichia bostrychion and more suborbicular. The dorsolateral hook in Metrichia bostrychion is also stouter than that of Metrichia anisoscola . Metrichia bostrychion can also be distinguished by the 3rd spine on the phallus which spirals dorsally.

Description.

Male. Length of forewing 1.8 mm (n=1). Head unmodified, with 3 ocelli; antennae unmodified. Tibial spur count 1, 3, 4. Dorsum of head dark brown with white setae; thorax dark brown with white and dark brown setae dorsally, brow n ventrally; leg segments with brown setae. Forewings covered with fine dark brown setae with small patch of light brown setae at apex. Abdomen with internal sacs between segments IV–V. Dorsolateral setal brushes on segments IV and V. Genitalia. Abdominal sternum VII with short, pointed mesoventral process. Segment VIII unmodified. Segment IX anterolateral margin very elongate, narrowing, withdrawn into segments VII–VIII, posterolateral margin convex; dorsally with posterior margin membranous, flat. Preanal appendage (cercus) short, rounded. Dorsolateral hook stout, strongly decurved (see Fig. 3A). Inferior appendage suborbicular with shallow posterolateral emargination, extends as high as segment IX. Tergum X membranous, apex subdeltoid in dorsal view. Phallus widest at base, narrowing to median constriction, membranous apex with 3 spines, 1st and 3rd slender, elongate, 2nd spiraling dorsad.

Material examined.

Holotype male:VENEZUELA: Monagas: Guachero Cave National Park at La Paila waterfall, 10°10.322'N, 63°33.315'W, 1110 m, 20-21.vii.2010, sweep net, Holzenthal, Thomson (UMSP000095197) (UMSP).

Paratype.

same data as holotype, 1 female (UMSP).

Etymology.

The diminutive of the Greek word bostrychos meaning “curl”, referring to the small spiral in the second apical spine on the phallus.