Mortoniella (Mortoniella) curvistylus, 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 : 85-86

Mortoniella (Mortoniella) curvistylus , new species

Fig. 71

Mortoniella curvistylus has a general similarity to other species in the argentinica subgroup, particularly in the possession of an elongate and strongly curved dorsal process on the inferior appendages and very elongate spine-like processes from the mesal pockets of the inferior appendages. Unlike the other species in this group, it seems to have only 1 pair of paramere appendages (possibly a secondary loss?). It has a relatively narrow V-shaped emargination of tergum X, but wider and more distinct than in either M. cornuta , n. sp. or M. spinulata (Flint) . The most unusual and diagnostic feature of this species is that the dorsal phallic spine seems to be fused or semi-fused to the endophallic membrane, from which point a retrorse spine emerges that articulates with a depression on the basodorsal margin of the phallicata.

Adult —Length of forewing: male 3.8 mm. Forewing with forks I, II, and III present, hind wing with forks II, III, and V. Spur formula 0:4:4. Head distinctly small. Overall color dark brown. Tibial spurs slightly darker than legs, contrasting in color. Wing bar at anastamosis marked with white setae.

anterolaterally, length greatest midlaterally, posterolateral margin slightly produced, narrowing ventrally; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by much less than ½ width of segment. Tergum X moderate in length, basally with rounded elevation, lateral margins subparallel, apicomesal margin with narrow V-shaped incision, apicolateral lobes formed by apical incision, apices of lobes somewhat ventrally curved, subacute; ventrolateral lobes prominent, rounded. Inferior appendages with very elongate, narrow, posteriorly recurved, dorsolateral lobes, apicoventral projections absent. Mesal pockets of inferior appendage with spine-like apical processes narrow, very elongate, posteriorly projecting. Paramere appendage single on each side, narrow, elongate (extending about as far as dorsal phallic spine), distinctly widened preapically, widened preapical expansion with several spines, apex acute. Dorsal phallic spine, in lateral view, almost uniformly narrow, apical 1/3 weakly upturned, spine possibly fused or semifused to phallicata at inflection; as viewed dorsally, relatively broad in middle, gradually narrowing apically, apex acute. Phallobase with very small, lightly sclerotized, mesal apodeme. Phallicata relatively elongate, tubular, apicodorsal margin (or base of endophallic membrane) with retrorse, spine-like projection, emerging at inflection point of dorsal phallic spine, apex of spine articulating with basodorsal margin of phallicata. Endophallic membrane short, simple in structure, without spines; phallotremal spines apparently absent.

Holotype male (pinned)— ECUADOR: Zamora-Chinchipe: 30 km E Loja, el 2000 m, 23.ix.1990, OS Flint, Jr ( UMSP000146418 ) ( NMNH).

Etymology —This species is named M. curvistylus from the Latin curvus, meaning bent, and stylus, a sharp pointed instrument, and referring to the unusual retrorse spine on the endophallic membrane that hooks backward to contact a depression in the dorsal margin of the phallicata.

Figures

Figure 71. Mortoniella (Mortoniella) curvistylus, 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.