Xiphocentron (Sphagocentron) eurybrachium, Vilarino & Calor, 2024

Vilarino, Albane & Calor, Adolfo R., 2024, Comparative geometric morphometrics of male genitalia in Xiphocentron subgenera (Trichoptera: Xiphocentronidae): new species, revision and phylogenetic systematics of the subgenus Sphagocentron, Arthropod Systematics & amp; Phylogeny 82, pp. 407-431 : 407-431

Xiphocentron (Sphagocentron) eurybrachium sp. nov.

Figures 7 A – F

Type material.

Holotype: VENEZUELA • ♂; Falcón, Mitare river, near San Luis , 11 ° 07.930 ′ N, 69 ° 39.184 ′ W, el. 589 m, 07. vi. 2001, Holzenthal, Blahnik, Paprocki, Cressa leg., UMSP 000074031 . — Paratypes: VENEZUELA • 6 ♂; same data as holotype, UMSP 000074032 , 000074033 , 000074034 , 000074035 , 000074036 , 000074037 .

Diagnosis.

Xiphocentron eurybrachium sp. nov. is mostly similar to Xiphocentron (S.) dactylum sp. nov.. However, X. eurybrachium sp. nov. can be differentiated mainly by the presence of the following characters: (1) the preanal appendage in lateral view conspicuously wide subapically (2 × wider than basal section), without narrow digitate projection; (2) inferior appendage basal region (coxopodite) with small spine-like setae in ventral view, apex curved dorsolaterally in dorsal view; (3) paraproct ventroapical lobe wide (as wide as preanal appendage basal section) (narrow or indistinct in the other species); (4) sternum IX trapezoid, posterior margin without incision; (5) sternum V with a digitate lateral projection.

Description.

Male: Forewing length 3.5–3.8 mm (n = 7). Wing without spots. Color overall brown, forewing uniformly dark brown. Maxillary palp segment length formula (I = II = III) <IV <V. Tibial spur formula 2: 4: 3; spurs unmodified. Forewing forks II and IV present; fork II sessile at discoidal cell; discoidal cell 3 / 4 as long as thyridial cell, very conspicuous nygmata. Hind wing forks II and V present (Fig. 7 A ). Sternum V with elongate, digitate, lateral glandular process (Fig. 7 F ).

Genitalia (Figs 7 B – E ). Tergum IX, in lateral view, wide basally, narrower apically (Fig. 7 B ); in dorsal view, anterior margin substraight; posterior margin with very narrow incision (Fig. 7 C ). Sternum IX, in lateral view, length more than 2 × as long as high, apex subtruncate, posterior margin concave, with a posterobasal short projection, anterior apodeme short, wide (Fig. 7 B ); in ventral view, about as long as wide, posterior margin slightly produced posterad, mesally convex, with a posteromesal, short projection (Fig. 7 D ). Tergum X membranous fused dorsally to each paraproct (Figs 7 B , 7 C ). Paraproct, in lateral view, oblong, narrow basaly, wider apically, apex subtruncate, with wide round ventroapical lobe (Fig. 7 B ); in dorsal view, wide basally, narrowed mesally and wide apically, divided apicomesally, each side fused at midlenght, with narrow sclerotized mesal band, apex with line of sparse sensillae (Fig. 7 C ). Preanal appendage, in lateral view, setose, about 2.5 × as long as tergum IX, wide, substraight throughout length, apically wide, 2 × as wide as base, with short, narrow projection (Fig. 7 B ); in dorsal view, narrow and curved mesally throughout length, tapered apically (Fig. 7 C ). Inferior appendage, in lateral view, about 2.5 × as long as tergum IX, coxopodite and harpago completely fused to each article, inner face with longitudinal area of dense, long spine-like setae, spine-like setae shorter towards base, with multiple lines of regular setae from midlenght to apex (Fig. 7 B ), (Fig. 7 D ); basal region (coxopodite) wide, with several basomesal short spine-like setae, mesal sclerite region indistinct (Fig. 7 B ); apical region (harpago) narrow, digitate, 2 × as long as basal region, apex slightly globose and curved dorsally; (Fig. 7 B ); basal plate in lateral view, wide, anteriorly with long, narrow flange (Fig. 7 B ). Phallus tubular, very long and narrow, reaching segment V, basally conical, subapically annulate, weakly sclerotized, apex enlarged (Fig. 7 E ).

Etymology.

From the Greek eurus, ‘ wide’, and brakhíōn, ‘ arm’ in reference to the preanal appendage shape in lateral view.

Distribution.

Venezuela.

Figures

Figure 7. Xiphocentron (Sphagocentron) eurybrachium sp. nov., holotype, male (UMSP). A wing venation left. Genitalia: B left lateral, C dorsal, D ventral, E phallus dorsal, F sternum V left ventral reticulate region. Scale bar: 0.1 mm.