Mortoniella (Mortoniella) iridescens Flint, 1991

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 : 41-42

Mortoniella (Mortoniella) iridescens Flint, 1991

Fig. 25

Mortoniella iridescens Flint 1991: 24 ; Sykora 1999: 386 [member of bilineata subgroup]; Blahnik and Holzenthal 2008: 70 [member of bilineata group]; Blahnik and Holzenthal 2011: 63 [member of bilineata subgroup].

This is a very distinctive species that is unlikely to be confused with any other species. Flint discussed the unusual iridescent bands on the forewing in the original description of the species. The character is probably unique for this species, but likely evident only in pinned specimens. The structure of the tergum X is the most diagnostic feature in that it is short and truncately thickened apically, as viewed laterally, and has a distinct rounded apicomesal notch. Other useful diagnostic characters, considered collectively, include the ventrolateral lobes of the endophallic membrane, which are covered with minute spines, the very acutely angled ventral projection from the dorsal phallic spine, the obtusely angled apical bend of same structure, and the absence of a mesal projection on the inferior appendages.

Adult —Length of forewing: male 4.8-5.1 mm. Forewing with forks I, II, and III present, hind wing with forks II, III, and V. Spur formula 0:4:4. Overall color dark brown (fuscous). Legs with basal part of mesotibiae and apices of mesotarsi somewhat paler. Tibial spurs slightly darker than legs, not greatly contrasting in color. Forewing with 2 iridescent turquoise wing bands, 1 at anastomosis and 1 on proximal part of wing, bands only visible at oblique angle, disappearing with light directly overhead.

Male genitalia —Ventral process of segment VI posteriorly projecting, prominent, length about 2 times width at base. 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 short, basal part inflated and set off from apical part; overall shape, as viewed dorsally, subquadrate, with distinct small U-shaped apicomesal invagination, tergum laterally with short rounded ventrolateral lobes, each with prominent apical setae; apex of tergum, in lateral view, distinctly sclerotized, subtruncate, with ventrolateral margins incurved and nearly converging mesally, mesal notch distinct; tergum ventromesally with paired, lightly sclerotized, ventromesal lobes at about midlength, each with short setae. Inferior appendages with short rounded setose dorsolateral lobes, appendages constricted ventromesally, without mesal projection. Mesal pockets of inferior appendage with short, posteriorly-directed, spine-like, apicoventral projections. Paramere appendage short, narrow, nearly uniform in width, apex acute; fused basal segments of appendage articulating near middle of basal stem of dorsal phallic spine. Phallobase with evident rounded, laterally compressed, dorsomesal apodeme. Dorsal phallic spine, as viewed laterally, with dorsal margin curved basally, then extending nearly straight and obtusely angled in apical ¼, apex of spine rounded; base of spine narrow, curved and stalk-like, abruptly and strongly widened on ventral margin at about midlength, forming very acute ventral projection, narrowing apically from projection; spine, as viewed dorsally, distinctly widened at ventral projection, narrowing basally and apically, apex rounded. Phallicata with sclerotized basodorsal projection, articulating with angular ventral projection of dorsal phallic spine; phallicata lightly sclerotized ventrally, sclerotization narrowly extending mesally. Endophallic membrane with welldeveloped membranous dorsolateral lobes, and smaller ventrolateral lobes with minute spines; phallotremal spines absent.

Material examined — COLOMBIA: Antioquia: 12 km N Fredonia, 2000 m, 22.ii.1983, OS Flint, Jr– 2 male Paratypes (pinned) (NMNH).

Distribution — Colombia.

— quinuas subgroup

Included species: Mortoniella gilli , n. sp. and M. quinuas Harper and Turcotte.

Mortoniella quinuas Harper and Turcotte was placed in the flinti subgroup by Sykora (1999), possibly because of the contour of the dorsal phallic spine, which lacks an angular ventral projection. However, the species is distinctly different from species in the flinti subgroup. We have placed the two species considered here in their own subgroup, even though it is conceivable that the two subgroups may be related. Mortoniella quinuas does seem to be correctly placed in the bilineata group, based on overall structural considerations. Female genitalia, which are distinctive for the group, would help to confirm this, but are not known or not available for confirmation. The second species described in this subgroup, M. gilli , n. sp., has a similarly developed dorsal phallic spine, with the apex very strongly recurved and covered with minute spines, and apparently also has a similarly shaped tergum X, with projecting apicolateral lobes. Both species also have elongate spine-like projections from the mesal pockets of the inferior appendages. The structure of the inferior appendages seems to be very different in the two species. Nevertheless, their relationship seems likely. Unfortunately, the holotype of M. quinuas , which was reillustrated by Sykora, could not be located for direct comparison. Mortoniella gilli lacks ventromesal processes on tergum X and also lacks an elongate membranous extension between segments VIII and IX. It is likely that the same is true for M. quinuas .

Figures

Figure 25. Mortoniella (Mortoniella) iridescens Flint, 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.