Polyplectropus beccus Hamilton and Holzenthal

Hamilton, Steven W. & Holzenthal, Ralph W., 2005, Five new species of Polycentropodidae (Trichoptera) from Ecuador and Venezuela, Zootaxa 810, pp. 1-14 : 11-12

Polyplectropus beccus Hamilton and Holzenthal , new species

Fig. 5 , 6

While wing venation indicates affinities to the New World Polyplectropus ( Fig. 5 ), the male genitalia resemble no known New or Old World species of this genus ( Fig. 6). The shape of the preanal appendage ( Fig. 6 A, B & D) is unique among Polyplectropus , and to our knowledge all known polycentropodids. The 4, heavy and truncate setae on the dorsal lobe and the bifurcate posterior process of the preanal appendage ( Fig. 6 A & B) are diagnostic. The phallus has a pair of large, symmetrical spines in the phallic membranes ( Fig. 6 E), an elongate phallic sclerite ( Fig. 6 E & F), and a bluntly forked process in the apicodorsal phallic membranes ( Fig. 6 G). The inferior appendages ( Fig. 6 A, C & D) resemble New World Polycentropus in the medial connection more than they resemble those of Polyplectropus , which are often broadly joined.

Adult. Length of forewing: male 5.5–6.5 mm (n=3). Body pale brown to yellow, legs stramineous, dorsum of head and thorax brown, clothed with long, dark setae; general vestiture of forewing with fine brown to dark brown setae, with many small patches of golden setae, base of forewing with long, erect setae.

Male. Genitalia as in Fig. 6. Posteromesal region of tergum VIII produced posteriad, shelf­like, with apical patch of microsetae. Sternum IX in lateral view subquadrate, in ventral view quadrate; anterior margin emarginate, posterior margin slightly produced medially. Tergum IX and X membranous, very reduced. Intermediate appendage absent. Preanal appendage very short, densely setose, with patch of stout, blunt setae apically, rounded, broad basally; mesoventral process triangular, directed ventrad, apex bifurcate, beak­like, with sclerotized dorsal branch and more slender, less sclerotized, closely appressed ventral branch. Inferior appendage densely setose, elongate, dorsoventral height less than length; dorsolateral flange an elongate lobe; ventrally with short, lobate projection. Phallobase moderately elongate; apicoventral projection absent; phallic membranes with single pair of long, curved spines; phallic sclerite oval, moderately elongate, apicolateral corners acute. Subphallic sclerite absent, but subphallic semisclerotized band connecting bases of preanal appendages beneath phallus.

Holotype male: VENEZUELA: T. F. Amazonas [=Estado Amazonas]: Puerto Ayacucho (40 km S), El Tobogan, Caño Coromoto, 24 January 1989, malaise, P.J. Spangler, R.A. Faitoute, C.B. Barr ( NMNH).

Paratypes: VENEZUELA: T. F. Amazonas [=Estado Amazonas]: Puerto Ayacucho (29 km S), Río Agua Blanca, 17 November 1987, P.J. Spangler, R.A. Faitoute— 1 male ( NMNH); same data as holotype— 1 male ( UMSP).

Etymology. From beccus, Latin for beak or bill, referring to the bifurcate process of the preanal appendage that resembles a birds beak in lateral aspect.

Figures

FIGURE 5. Polycentropus beccus, new species. Wings: A—forewing; B—hind wing.