Mortoniella (Mortoniella) variabilis, 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 : 70-71

Mortoniella (Mortoniella) variabilis , new species

Fig. 55

Mortoniella variabilis is very similar to M. gracilis , n. sp. and M. limona (Flint) . All of these species have elongate basoventral projections from the phallicata, a distinguishing feature of this complex. The shape of these projections is variable in each of these species, but in M. variabilis the projections tend to be narrower and longer than in M. gracilis . The most diagnostic feature distinguishing the species in this complex is the shape of the apex of the dorsal phallic spine. Unfortunately, this is somewhat variable, even within the species, and this is especially so for M variabilis . In general, the ventral projection at the apex of the dorsal phallic spine is less produced in M. variabilis than in M. limona , but more so than in M. gracilis . The ventral projection often (or perhaps usually) has a distinct, upturned, spine-like projection, not present in M. limona . The development of this spine is quite variable in the material examined, as is the length of the paramere appendages (see Fig. 55D for an extreme variant from Colombia). We are interpreting this as variation within a species, but the issue may be worthy of reinvestigation when more material is available. There was no evident difference in the female genitalia of specimens from Colombia and Venezuela. Mortoniella variabilis is probably more likely to be confused with M. limona than M. gracilis , because the ventral projection of the dorsal phallic spine is distinctly produced in both species, but the character state in M. variabilis never reaches the extreme condition found in M. limona . Also, the apex of the dorsal phallic spine, above the ventral expansion, tends to be narrower and more attenuate in M. variabilis than in M. limona . In most material of M. variabilis , only 1 pair of endophallic spines is evident, but in specimens with the armature fully expanded, a second, very lightly sclerotized pair may also be evident; the second pair may be a consistent feature, not easily observed unless the armature is completely everted. In the other two species, 2 pairs of sclerotized spines are generally evident, even when the armature is not expanded.

Adult —Length of forewing: male 2.7-3.4 mm; female 3.0-3.9. Forewing with forks I, II, and III present, hind wing with forks II and III. Spur formula 0:4:4. Overall color medium brown, apices of tarsal segments and basal segments of antennae pale brown. Tibial spurs darker than legs, contrasting in color. Wing bar at anastamosis indistinct, marked with light brown setae, most evident at arculus.

Male genitalia —Ventral process of segment VI laterally compressed, ventrally projecting, large, subtriangular, length about equal to width at base, process not retracted anterobasally. Segment IX nearly evenly rounded anterolaterally, length greatest midlaterally, posterolateral margin weakly rounded, narrowing ventrally; segment deeply mesally excised dorsally and ventrally, forming lateral lobes, separated dorsomesally by less than ½ width of segment. Tergum X relatively short, lateral margins subparallel, apicomesal margin with V-shaped or U-shaped emargination between apicolateral lobes, extending about 1/3 length of tergum; apicolateral lobes tapered, acute apically, short and narrow as viewed laterally; apicomesal lobes visible in lateral view, rounded apically; ventrolateral lobes distinct, projecting. Inferior appendages somewhat variable shape, with short tapering dorsolateral lobes and apicoventral projections very short or absent. Mesal pockets of inferior appendage with apical processes moderately large, posterodorsally curved. Paramere appendage short or moderate in length (shorter than dorsal phallic spine), narrow, nearly uniformly in width, apex acute. Dorsal phallic, as viewed laterally, compressed apically, with prominent rounded apicoventral expansion and (usually) an acute, dorsally-oriented projection from ventral margin; apex of dorsal phallic spine narrowing and attenuate, often slightly posteriorly curved; spine, in dorsal view, nearly uniform in width, apex acute. Phallicata with dorsal margin sclerotized, extending into endophallic membrane, with apical depression to accommodate apicoventral projection of dorsal phallic spine, basoventrally with pair of very prominent curved, apically rounded, sclerotized, projections. Endophallic membrane short, with one pair of prominent sclerotized spines, and second pair of smaller, lightly sclerotized spines (possibly sometimes absent); ventromesal spine absent.

Holotype male (pinned)— VENEZUELA: Zulia: Parque Nacional Perijá, Río Negro in Toromo , 10.051° N, 72.712° W, el 360 m, 15.i.1994, Holzenthal, Cressa, Rincón ( UMSP000001386 ) ( UMSP).

Paratypes — COLOMBIA: Magdalena: Municipio Ciénaga, Río Cordoba, 25 km NS “Estacion Exp. San Lorenzo,” Sierra Nevada de Santa Marta , 11.03944° N, 74.03833° W, el 930 m, 12.xii.1997, F Muñoz-Q et al.– 5 males, 14 females (pinned) ( UMSP) ; Municipio de Santa Marta, Río Minca en Minca , 11.14306° N, 74.11611° W, el 570 m, 9.xii.1997, F. Muñoz-Q et al.– 1 male, 1 female (pinned) ( UMSP) ; Meta: Quebrada Blanca, 3 km W Restrepo, 11.ii.1983, OS Flint, Jr – 1 male (alcohol) ( NMNH) ; VENEZUELA: Barinas: Parque Nacional Sierra Nevada, Quebrada San Juan in Santa Rosa, 8.46450° N, 70.84867° W, el 1000 m, 21.iii.1997, Holzenthal – 2 males, 5 females (alcohol) ( UMSP) ; 22 km N Barinitas , 24.ii.1976, CM & OS Flint, Jr – 1 male, 2 females (alcohol) ( NMNH) ; Zulia: same data as Holotype– 2 males, 2 females (pinned), 3 males (alcohol) ( UMSP), 2 males, 2 females (alcohol) ( NMNH), 2 males, 2 females (alcohol) ( MIZA) .

Etymology —This species is named M. variabilis because of the variability in the structure of the apex of the dorsal phallic spine and length of the paramere appendages.

— pocita subgroup

Included species: Mortoniella pocita (Flint) .

This subgroup was proposed by Blahnik and Holzenthal (2011) to contain only M. pocita (Flint) . The species was originally described from Argentina and subsequently listed from Bolivia by Rueda Martín and Gibon (2008). It has a general similarity to several of the species listed below as leroda group species “unplaced to subgroup,” especially in having elongate inferior appendages and a modified apex of the dorsal phallic spine. However, none of these species have elongate dorsal processes on the phallicata, a character found in M. pocita and also used to define the punensis subgroup. Because of our uncertainty about whether this reflects a relationship between these 2 subgroups, and because of its unusual overall combination of characters, we are continuing to list M. pocita in its own subgroup.

Figures

Figure 55. Mortoniella (Mortoniella) variabilis, new species male genitalia. A—lateral; B—segment IX and tergum X, dorsal; C—phallic ensemble, ventral; D—lateral, specimen from Colombia.