Mortoniella (Mortoniella) longiterga, Blahnik & Holzenthal, 2017

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 : 38-39

Mortoniella (Mortoniella) longiterga , new species

Fig. 23

This species is most closely related to M. foersteri (Schmid) and like that species has the posterior margin of segment IX broadly rounded and the ventral margin of the dorsal phallic spine very angularly developed. It is distinguished from M. foersteri by its distinctly longer tergum X and also by its smaller size.

Adult —Length of forewing: male 4.7 mm. Forewing with forks I, II, and III present, hind wing with forks II, III, and V. Spur formula 0:4:4. Overall color brownish-black (fuscous). Tibial spurs slightly darker than legs, but not greatly contrasting in color. Forewing without white wing bars.

Male genitalia —Ventral process of segment VI posteriorly projecting, moderately prominent, narrow basally, length about 2-2½ times width at base, apex acute. Tergum VIII relatively narrow, subtending ventral margin of segment IX, membranous connection to tergum IX elongate. Segment IX with anterolateral margin rounded and produced in ventral half, posterolateral margin broadly rounded; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by more than ½ width of segment. Tergum X elongate, basal part slightly inflated and set off from elongate sclerotized apical part, laterally with very short rounded ventrolateral lobes, each with 1 or 2 prominent setae; tergum, as viewed dorsally, very elongate, narrow, lateral margins subparallel, apices truncate; apex of tergum distinctly sclerotized, with ventrolateral margins incurved and nearly converging mesally, mesal notch small, but distinct, dorsally, with short U-shaped connection; tergum ventromesally with paired, lightly sclerotized, ventromesal lobes in basal half, each with short setae. Inferior appendages with short upright dorsolateral lobes, ventromesal lobes absent. Mesal pockets of inferior appendage with short, posteriorly-curved, spine-like, apicoventral projections. Paramere appendage elongate, narrow, nearly uniform in width, apex acute, extending about same length as dorsal phallic spine; fused basal segments of appendage articulating near base of dorsal phallic spine. Phallobase with rounded, laterally compressed, dorsomesal apodeme. Dorsal phallic spine, as viewed laterally, relatively narrow, dorsal margin nearly straight from base, sinuously deflected and then strongly, nearly rectilinearly, upturned in apical 1/4, apex of spine rounded; base of spine narrow and stalk-like, abruptly and strongly widened on ventral margin at about basal half, forming acute spine-like ventral projection, narrowing apically from projection; as viewed dorsally, nearly uniformly narrow throughout length. Phallicata with sclerotized basodorsal projection, articulating with spine-like ventral projection of dorsal phallic spine, sclerotization extending dorsally from spine and conforming to ventral margin of dorsal phallic spine; phallicata ventrally with pair of projecting sclerotized basal lobes, sclerotization not extending beyond lobes. Endophallic membrane with pleated membranous lateral lobes; phallotremal spines absent.

Holotype male (pinned)— ECUADOR: Pichincha: 2.3 km S Tandayapa , 1800 m, 6.ix.1990, OS Flint, Jr ( UMSP000157312 ) ( NMNH).

Etymology —This species is named M. longiterga for its very elongate tergum X, which helps to distinguish it from M. foersteri .

— hodgesi subgroup

Included species: Mortoniella hodgesi Flint.

This species was included in the bilineata subgroup by Sykora, but is removed and placed in its own subgroup here because of its unusual combination of characters. The only specimens examined were from alcohol, but the color is apparently brownish black (fuscous), without forewing wing bars. Males of this species have tergum X very deeply invaginated mesally, without the evident enrolling of the lateral margins typically found in the apiculata, bilineata, and enchrysa subgroups. Like species in the M. apiculata and M. enchrysa groups, the ventral process of segment IV is very small. Otherwise, the angular posterolateral margin of segment IX and the dorsal phallic spine, with a very distinctly produced ventral margin (although rounded and not angular), and with the apical part bent at nearly a right angle and with the apex rounded, as viewed laterally, is very similar to species of several subgroups, including the bilineata, apiculata, and enchrysa subgroups. The primary feature distinguishing this species group and suggesting a relatively basal position in the entire bilineata group clade, is the structure of the female genitalia ( Fig. 109 ), which is rather minimally modified, with the usual mesal notch in tergum VIII indicated only by being lightly sclerotized, and without an anterior projection of tergum IX, which normally extends into the mesal notch of tergum VIII in other members of the bilineata group. Male characters that are unusual include a basal part of tergum X that is not inflated or distinctly separated from the apical part; elongate, curved apicolateral processes of tergum X with very elongate setae; and very minimally developed ventromesal processes of tergum X, which lack a spatulate mesal projection and are retracted so that they are not directly visible in lateral view.

Figures

Figure 23. Mortoniella (Mortoniella) longiterga, new species, 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.

Figures 108-109. Mortoniella (M.), bilineata group species, female genitalia. 108—Mortoniella catherinae, n. sp. A—lateral; B—dorsal; C—ventral. 109—Mortoniella hodgesi Flint. A—lateral; B—dorsal; C—ventral.