Xiphocentron (Sphagocentron) dactylum, 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) dactylum sp. nov.

Figures 6 A – E

Type material.

Holotype: VENEZUELA • ♂; Falcón, P. N. Cueva de la Quebrada del Toro, Quebrada del Toro , 10 ° 49.581 ′ N, 69 ° 07.990 ′ W, el. 530 m, 11. vi. 2001, Holzenthal, Blahnik, Paprocki, Cressa leg., UMSP 000075081 . — Paratypes: VENEZUELA • 1 ♀; same data as holotype, UMSP 000075082 . • 1 ♂; Aragua, Tiara , 30. i. 1983, Flint leg., USNMENT 01518180 .

Diagnosis.

Xiphocentron dactylum sp. nov. is particularly similar to Xiphocentron (S.) eurybrachium sp. nov. mainly by the shape of the preanal appendage (in lateral view, straight throughout length, apically wide). However, X. dactylum sp. nov. can be differentiated from its congener by the (1) shape of sternum IX in ventral view, elongate and about as wide basally as apically, subrectangular (trapezoid, conspicuously wider apically in X. eurybrachium sp. nov.), by (2) the posterior margin of sternum IX with wide shallow V-shaped incision (absent in X. eurybrachium sp. nov.) in ventral view.

Description.

Male: Forewing length 3.0 mm (n = 2). Color overall dark 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 half as long as thyridial cell. Hind wing forks II and V present. Sternum V with anterolateral reticulated round region (Fig. 6 E ).

Genitalia (Fig. 6 A – D ). Tergum IX, in lateral view, narrow basally, acuminate apically (Fig. 6 A ); in dorsal view, anterior margin straight; posterior margin with round lobes and mesal V-shaped incision, and narrow suture line (Fig. 6 B ). Sternum IX, in lateral view, length more than 2 × as long as wide, apex subdeltoid; anterior apodeme short, wide (Fig. 6 A ); in ventral view, about 2 × as long as wide, posterior margin with V-shaped mesal incision (Fig. 6 C ). Tergum X membranous fused basodorsally to each paraproct. Paraproct, in lateral view, oblong, width subequal throughout length, apex round, with narrow, short ventral lobe (Fig. 6 A ); in dorsal view, wide basally, narrowed mesally and wide apically, divided apicomesally, each side partially fused at base, without clear sclerotized mesal band, apex with several sensillae (Fig. 6 B ). Preanal appendage, in lateral view, setose, length more than 2 × as long as tergum IX, wide, straight throughout length, apically wide, 1.5 as wide as base, with narrow digitate projection (Fig. 6 A ); in dorsal view, narrow throughout length, wide at apex with digitate projection curved mesad (Fig. 6 B ). Inferior appendage, in lateral view, about 2 × as long as tergum IX, curved mesally in dorsal view (Fig. 6 B ); coxopodite and harpago completely fused to each article, inner face with longitudinal area of numerous, slightly sparse, spine-like setae, mesal sclerite region with dense, long spine-like setae, with line of regular setae from midlenght to apex (Fig. 6 A ); basal region (coxopodite) wide, without clear basomesal spine-like setae; apical region (harpago) narrow, digitate, about as long as basal region, apex slightly globose and curved distad (Fig. 6 A ); basal plate in lateral view wide (Fig. 6 A ). Phallus tubular, very long and narrow, reaching segment V, basally conical, subapically annulate, weakly sclerotized, apex enlarged (Fig. 6 D ).

Etymology.

From the Greek dáktulos, ‘ finger’, in reference to the conspicuous digitate projection of preanal appendage curved mesad.

Distribution.

Venezuela.

Figures

Figure 6. Xiphocentron (Sphagocentron) dactylum sp. nov., holotype, male (UMSP). Genitalia: A left lateral, B dorsal, C ventral, D phallus dorsal, E sternum V left ventral reticulate region. Scale bar: 0.1 mm.