Mortoniella (Mortoniella) proakantha, 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 : 88-89

Mortoniella (Mortoniella) proakantha , new species

Fig. 74 , 114

Mortoniella proakantha bears an overall similarity to members of the akantha subgroup of the leroda group, particularly in the shape of the inferior appendages, which have a symmetrical mesal projection and narrow, recurved dorsolateral projections, and also have mesal pockets with short spine-like ventral projections. It differs diagnostically in having fork V of the hind wing present (Cu 1 forked apically) and in having a very elongate, narrow ventral process on segment VI (both probably plesiomorphic characters). Additionally, the dorsal phallic spine is unusual in having a long curved basal stalk (as in many members of the bilineata group) and an apex that is bifid and has many minute spines.

Adult —Length of forewing: male 3.5-3.7 mm; female 4.0 mm. Forewing with forks I, II, and III present, hind wing with forks II, III, and V. Spur formula 0:4:4. Color (in alcohol) brown. Tibial spurs darker than legs, contrasting in color. Wing bar not evident.

Male genitalia —Ventral process of segment VI very narrow and elongate, posteriorly directed, length about 6 times width at base, apex acute. Segment IX nearly evenly rounded anterolaterally, length greatest midlaterally, posterolateral margin broadly rounded, narrowing ventrally; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by less than ½ width of segment. Tergum X moderately elongate, lateral margins subparallel, apicomesal margin with relatively shallow U-shaped or V-shaped emargination, apicolateral lobes short, inset from lateral margin, apices distinctly sclerotized and somewhat ventrally curved; ventrolateral lobes narrow, elongate, projecting, rounded apically, with elongate setae. Inferior appendages with very elongate, narrow, posteriorly recurved, dorsolateral projections, somewhat detached or inset from lateral margin, apices acute, with few minute spines, apicoventral projection of appendages prominent, elongate, apex subtruncate. Mesal pockets of inferior appendage with spine-like apical processes short, posterodorsally curved. Paramere appendage relatively short (much shorter than dorsal phallic spine), slightly widened in apical ½, apex acute, with numerous small spines-. Basal segment of paramere enlarged and elevated, subtending dorsal phallic spine at apex of long basal stalk. Dorsal phallic spine, as viewed laterally, with elongate, narrow basal stalk, apical ½ narrow, undulate in contour, apex with minute spines, slightly upturned; spine, as viewed dorsally, narrow throughout (basal ½ very narrow), apex acutely bifid, with minute spines. Phallicata narrow basally, expanded dorsally to form rounded elevation, apparently articulating with dorsal phallic spine. Endophallic membrane simple, without spines; phallotremal spines absent.

Holotype male (alcohol)— ECUADOR: Napo: OY10 unnamed trib. to Oyacachi R., ca. 5.2 mi W of Oyacachi ( UMSP000097164 ) ( NMNH).

Paratypes — ECUADOR: Napo: same data as holotype – 1 male, 1 female (alcohol) ( NMNH).

Etymology —This species is named M. proakantha , from the Latin or Greek prefix pro -, meaning before, and referring to its retention of primitive characters and overall resemblance to species in the akantha subgroup.

— santiaga subgroup

Included species: Mortoniella acutiterga , n. sp.; M. santiaga Sykora.

The members of this subgroup are very unusual and have no obvious close relationship to other subgroups. Mortoniella santiaga was placed by Sykora in the flinti subgroup of the bilineata group. However, it has very few character similarities to either members of the flinti subgroup or to the bilineata group, other than its hind wing venation (Cu 1 forked or fork V present) and the narrow, elongate ventral process of segment VI, both undoubtedly plesiomorphic characters. Characters suggestive of a relationship to the bilineata group include the short, paired, sclerotized, ventral lobes of the phallicata and the sharply angled ventrolateral lobe of tergum X. Characters suggestive of a relationship to the leroda group include the overall shape of segment X (broadly rounded laterally and with lobes narrowly separated dorsally), the very short spine-like projections from the mesal pockets of the inferior appendages, and the absence of a dorsal apodeme on the phallobase. None of these characters are decisive. The rounded, elevated base of the phallicata somewhat resembles that of M. proakantha , n. sp. and M. unilineata Sykora , but whether this reflects a relationship is also uncertain. All of these species also have a very elongate, narrow ventral process on segment VI.

Figures

Figure 74. Mortoniella (Mortoniella) proakantha, 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 114-115. Mortoniella (M.), species, unplaced to species group, female genitalia. 114—Mortoniella proakantha, n. sp. A—lateral; B—dorsal; C—ventral. 115—Mortoniella unilineata Sykora. A—lateral; B—dorsal; C—ventral.