Polycentropus ancistrus Hamilton & Holzenthal

Hamilton, Steven W. & Holzenthal, Ralph W., 2011, Twenty-four new species of Polycentropus (Trichoptera, Polycentropodidae) from Brazil, ZooKeys 76, pp. 1-53 : 9

Polycentropus ancistrus Hamilton & Holzenthal sp. n. Fig. 4.

Description.

Polycentropus ancistrus sp. n. most closely resembles Polycentropus froehlichi . It is distinguished from Polycentropus froehlichi and the other urubici cluster species by the strongly incurved and acute apices of the dorsolateral flange and caudomesal spine of the inferior appendage as well as the near equal length of both processes of the preanal appendage.

Adult. Length of forewing (male) 6 mm. Body brown; dorsum of head and thorax brown; legs stramineous.

Male. Genitalia as in Fig. 4. Sternum IX in lateral view nearly round, slightly greater than 1/2 height of segment VIII; in ventral view slightly trapezoidal, anterior corners very sharply rounded, sides slightly convex, narrowed posteriorly, anterior margin shallowly concave, posterior margin shallowly concave. Terga IX + X membranous. Intermediate appendage straight, very long, length much greater than height of abdomen, basal region simple, not expanded; in dorsal view nearly uniform in diameter throughout length, gradually narrowing apically. Mesolateral process of preanal appendage moderately long, digitate, apex rounded, at base broadly joined to dorsal 1/2 of mesoventral process; mesoventral process directed caudad, size and shape of mesolateral process, slightly shorter than length of mesolateral process. Inferior appendage in lateral view moderately long, somewhat triangular; posteroventral margin acute below shallow caudal emargination; dorsolateral flange low, slightly excavated medially, apically tapered to sharp inturned point, with prominent caudomesal spine, exposed in lateral view; mesoventral spine absent; in ventral view inferior appendage broad basally, slender, tapering apically, caudomesal spine prominent, acute. Phallobase moderately short; in lateral view apicoventral projection narrow, slightly longer than apical diameter of phallobase apex, with 2 points; separated by very shallow median groove; endothecal sclerotic band forming flanges within phallobase; phallotremal sclerite difficult to discern due to specimen condition. Subphallic sclerite Y-shaped, arms long, pedicel narrow; narrow in lateral view, ventrally somewhat narrowed.

Holotype male:

BRAZIL: São Paulo: Res. Casa Grande, Rib. Courja, á luz, 26.i.1974, Froehlich, (UMSP000131229) (in alcohol) (MZUSP).

Etymology.

From the Greek ankistron for fishhook, in reference to the caudomesal spines on the inferior appendage of the male genitalia.