Mortoniella (Mortoniella) triramosa, 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 : 92

Mortoniella (Mortoniella) triramosa , new species

Fig. 77

This species is closely related to M. triden s, n. sp., as discussed in the diagnosis for that species. It can be distinguished by its shorter paramere appendages and more elongate inferior appendages, as well as by having a decurved ventromesal projection near the apex of the phallicata, rather than a pair of apicolateral lobes. It also lacks the wart-like projections on tergum X found in M. tridens .

Adult —Length of forewing: male 4.0 mm. Forewing with forks I, II, and III present, hind wing with forks II, III, and V. Spur formula 0:4:4. Overall color medium brown, apices of tarsal segments paler. Tibial spurs slightly darker than legs, weakly contrasting in color. Wing bar at anastomosis distinct, marked with white setae.

Male genitalia —Ventral process of segment VI laterally compressed, very large, subtriangular, ventrally directed, length subequal to width at base, apex acute, process not retracted anterobasally. Segment IX nearly evenly rounded anterolaterally, length greatest midlaterally, posterolateral margin slightly produced in dorsal ½, narrowing ventrally; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by much less than ½ width of segment. Tergum X relatively short, subquadrate, lateral margins subparallel, apicolateral lobes reduced to small trianguloid processes, inset from lateral margin, acute apically, barely visible in dorsal view; ventrolateral lobes prominent, rounded. Inferior appendages strongly fused to phallicata, distinguishable as such mostly by setae, lateral lobes obsolete, apicomesal margin slightly projecting. Mesal pockets of inferior appendage with spine-like apical processes moderately elongate, sinuous, posteriorly projecting. Paramere appendage short, narrow, with base displaced ventrally on membranous lobe, apex posterodorsally curved. Dorsal phallic spine cleft apically to form 3 narrow branches, mesal one dorsally inflected, lateral ones subparallel basally, divergently and laterally curved near apex. Phallicata with small ventromesal projection at apex. Endophallic membrane elongate, without membranous lobes or ventral spine; phallotremal spines only suggestively developed, very lightly sclerotized.

Holotype male (pinned)— BOLIVIA: Yungas La Paz: Circuata to Cajuata , 2400 m, 3- 5.xii.1984, LE Peña G ( UMSP000118512 ) ( NMNH).

Etymology —This species is named M. triramosa, Latin for three-branched, and referring to tripartite dorsal phallic spine of this species.

— unilineata subgroup

The single unusual species placed here was placed in the argentinica subgroup by Sykora, albeit with some hesitation. Sykora did not discuss the characters he used to establish his subgroups. Blahnik and Holzenthal (2012) suggested that both species of the argentinica subgroup should probably be removed from the bilineata group and were possibly unrelated. The only obvious characters linking the two species are the broadly rounded anterior margin of segment IX and the reflexed dorsal lobe of the inferior appendages. It should be noted that Sykora described the reflexed dorsal processes of the inferior appendages as being lateral paired processes (paramere appendages). True paramere appendages seem to be absent in this species. Both of the character similarities listed are probably plesiomorphic characters, and the latter of these would not have been evident to Sykora, based on his interpretation of the structure. Mortoniella unilineata has the anterior margin of segment IX somewhat produced in its ventral ½, as in species of the bilineata group, and the lobes are also further apart dorsally than most species in the leroda group. On the other hand, the female genitalia lack the mesal invagination of segment VIII that characterizes the bilineata group ( Fig. 115 ), implying that if it is related to this group, it must be in a more basal position than other described species. The very elongate ventral process of segment VI and elevated basal projection of the phallicata somewhat resembles the character states in M. proakantha , n. sp. and M. gilli , n. sp., both treated here as “unplaced species.” If these species are related, it cannot be a very close relationship, because they are all very apomorphically distinct. Possibly, they represent divergent members of a lineage basal to both the bilineata and leroda groups.

Figures

Figure 77. Mortoniella (Mortoniella) triramosa, new species, male genitalia. A—lateral; B—segment IX and tergum X, dorsal; C—phallic ensemble, ventral; D—dorsal phallic spine and phallobase, 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.