Mortoniella (Mortoniella) bifurcata Sykora, 1999

Blahnik, Roger J. & Holzenthal, Ralph W., 2017, Revision of the northern South American species of Mortoniella Ulmer 1906 (Trichoptera: Glossosomatidae: Protoptilinae) *, Insecta Mundi 2017 (602), pp. 1-251 : 34

Mortoniella (Mortoniella) bifurcata Sykora, 1999

Fig. 18

Mortoniella bifurcata Sykora 1999: 382 [member of flinti subgroup]; Blahnik and Holzenthal 2008: 70 [member of bilineata group].

This species is probably most closely related to M. flinti Sykora. Both species are very dark in color and have 2 white wing bands, and also have the apex of the dorsal phallic spine modified, bifurcate or asymmetric (as in the specimen illustrated) in M. bifurcata and trifurcate in M. flinti . The other two species in the group are dark in color, without wing bands, and have the dorsal phallic spine symmetric and either narrowed or rounded apically. The most diagnostic difference between M. bifurcata and M. flinti is in the apex of tergum X, which is only very shallowly notched apically in M. bifurcata and much more distinctly so in M. flinti . The difference in the shape of the inferior appendages, as illustrated by Sykora, is inaccurate and does not seem to be diagnostic. However, the spines from the mesal pockets of the inferior appendages in M. bifurcata are somewhat longer than In M. flinti ; also, the paramere appendages are longer, but not nearly as long as in M. tanyrhabdos , n. sp.

Adult —Length of forewing: male 3.8 mm. Forewing with forks I, II, and III present, hind wing with forks II and V. Spur formula 0:3:4. Overall color dark brownish-black (fuscous). Mesotarsi whitish, except at very apex. Tibial spurs slightly darker than legs, not strongly contrasting with legs. Forewing with distinct white wing bar at anastomosis, and evidence (on one wing of somewhat rubbed specimen) of second white wing bar on proximal part of wing, closer to base than anastomosis.

Male genitalia —Ventral process of segment VI posteriorly projecting, prominent, narrow basally, length about 3½ times width at base. Tergum VIII narrow, subtending ventral margin of segment IX, membranous connection to tergum IX moderately elongate. Segment IX with anterolateral margin rounded and produced in ventral half, posterolateral margin nearly straight, without distinct projection; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by less than ½ width of segment. Tergum X elongate, apex rounded, with only slight mesal invagination, lateral margins subparallel, with paired longitudinal ridges extending from basolateral margins to past midlength, ridges somewhat converging posteriorly; tergum with bluntly rounded ventrolateral lobes, ventromesal lobes absent. Inferior appendages with short rounded dorsolateral lobes, each with fringing row of very elongate setae, and short, bluntly rounded, ventromesal projection, subtending apical spine-like projections of mesal pockets of inferior appendages. Mesal pockets of inferior appendage with moderately elongate, posterodorsally curved, spine-like, apicoventral projections, projecting distinctly below ventral margin of phallicata. Paramere appendage relatively elongate, not extending to apex of dorsal phallic spine, narrow, nearly uniform in width, apex acute, strongly bent in about apical 1/3; fused basal segments of appendages articulating near base of dorsal phallic spine. Phallobase with evident rounded, laterally compressed, dorsomesal apodeme. Dorsal phallic spine, as viewed laterally, relatively narrow throughout, tapering apically, slightly dorsally curved in about apical 1/4, apex acutely bifid in holotype, unilaterally asymmetric in paratype ( Fig. 18D ); base of spine with short, curved stalk and distinct, rounded, ventral deflection in basal ¼; spine, as viewed dorsally, nearly uniformly narrow in width throughout length, apex bifid or acute and asymmetric. Phallicata with elongate sclerotized basodorsal projection, articulating with rounded ventral deflection of dorsal phallic spine, basolaterally with small rounded projection, ventral margin sclerotized and strongly arched. Endophallic membrane simple in structure, without membranous lateral lobes; phallotremal spines absent.

Material examined — VENEZUELA: Barinas: 22 km NW Barinitas, 19.ii.1976, CM and OS Flint, Jr– 1 male Paratype (pinned) (NMNH).

Distribution — Venezuela.

Figures

Figure 18. Mortoniella (Mortoniella) bifurcata Sykora, male genitalia. A—lateral; B—segment IX and tergum X, dorsal; C—phallic ensemble, ventral; D—dorsal phallic spine, dorsal; E—ventral process of segment VI, lateral.