Mortoniella collegarum (Rueda & Gibon, 2008) Blahnik & Holzenthal, 2011

Blahnik, Roger J. & Holzenthal, Ralph W., 2011, Revision of the austral South American species of Mortoniella (Trichoptera: Glossosomatidae: Protoptilinae) 2851, Zootaxa 2851 (1), pp. 1-75 : 51-53

Mortoniella collegarum (Rueda & Gibon, 2008) , new combination

Fig. 25

Mexitrichia collegarum Rueda & Gibon, 2008: 216

The illustrated specimen is from Chile. Although differing from the illustration of the type in several points, the essential features correspond and the differences seem to represent variable features. Diagnostic features are found in the strongly upturned dorsal phallic spine with a deep apicomesal incision and the apically incised lateral margins of tergum X. Although the apex of the dorsal phallic spine characteristically has the margin and mesal surface with small spines, these may be absent on the margin or completely absent. This is variable within the same population in the specimens recorded from Argentina. They are present in the specimens from Chile. A characteristic feature of this species is the outward curved spines at the base of the phallicata, which emerge from an enlarged, sclerotized collar. In the specimens examined, these spines are not as thick as those illustrated for the holotype. However, the development of the basal collar and the length of the spines also seem to be variable; the spines were even absent or vestigial in 1 of the specimens examined from Chile. What we have interpreted as paramere appendages are very lightly sclerotized, short, spine-like processes, which appear to be vestigial. These vary in length in the material examined; they are easily overlooked and it is possible that they may be absent in some specimens; they were not illustrated in the holotype specimen. The last notable difference of the specimens examined from the holotype are in the apical lobes of the endophallic membrane; there are 2 such lobes in the material examined, with sclerotized apical spines (probably phallotremal spines), and 4 prominent lobes with apical spines in the holotype. We have observed lobes similar to those of the holotype in some specimens from Bolivia (which, however, completely lack small apical spines on the dorsal phallic spine). In as much as this is a relatively minor feature, and only easily observed in specimens in which the endophallic membrane is expanded, we are considering this to be variation. All of the specimens we examined (for which the features could be ascertained) had a posteriorly directed dorsomesal spine from the posterior margin of the phallicata (or base of the endophallic membrane), which apparently articulates with the cleft apex of the dorsal phallic spine, and also lightly sclerotized (or nearly membranous) balloon-like projections from the lateral margin of the endophallic membrane. These were not featured or described for the holotype; they are also relatively minor features that may not have been present on the holotype specimen, or may not have been evident. Although we believe the variation described here can be accommodated in 1 variable species, we acknowledge that the species status of these populations may need to be reassessed when more material is available .

Adult. Length of forewing: male 2.1-2.5 mm, female 2.5-3.0. Forewing with forks I, II, and III present, hind wing with fork II only. Spur formula 0:3:4. Overall color medium brown, legs slightly paler, tibial spurs darker, but not strongly contrasting with legs. Wing bar at anastamosis marked with white, contrasting setae. Males with modified scale-like setae on forewing, scales not quite extending to apex.

Male genitalia: Ventral process of segment VI posteriorly projecting, elongate, narrow, length more than 2 times width at base; apex slightly dorsoventrally compressed, acute as viewed laterally, subacute as viewed ventrally. Segment IX rounded anterolaterally, length generally greatest in ventral 1/2, posterolateral margin nearly linear; segment deeply excised dorsomesally and ventromesally, forming lateral lobes, lobes separated dorsomesally by 1/2 or more width of segment. Tergum X moderately elongate, relatively simple in structure, with V-shaped mesal excision; apical lobes with rounded lateral excision, producing acute dorsal and ventral projections, as viewed laterally. Inferior appendages very small, inconspicuous, with acute posterior projection. Mesal pockets of fused inferior appendages with apical processes short, dorsally curved, extending beyond inferior appendages. Paramere appendages hyaline, very narrow, apices acute, variable in length and possibly sometimes absent. Dorsal phallic spine of distinctive structure, laterally with narrow, depressed projections, apically strongly upturned in apical 1/3rd; apex somewhat inflated and deeply incised mesally, producing paired lobes, each with minute spines on apical and mesal margin (minute spines absent in some specimens or populations). Phallicata with base strongly sclerotized and somewhat dorsally produced, forming basal collar; collar laterally with outwardly curved spine-like process on each side, apices of spines often somewhat swollen, with very small scale-like projections. Endophallic membrane (or apex of phallicata) with dorsomesal, posteriorly-oriented spine-like process; laterally, at midlength with lightly sclerotized or nearly membranous balloon-like projections; apicodorsally with either 2 or 4 lobes, each with small, sclerotized spine-like apex (probably phallotremal spines).

Material examined. ARGENTINA: Neuquen: Río Agrio , N . Zapala , 9-11.xii.1983, L E Peña G . — 4 males, 8 females (pinned), 6 males, 29 females (alcohol) ( NMNH, UMSP); CHILE: Curico: El Coigo, 1.iii.1968, Flint & Peña — 2 males (alcohol) ( NMNH). Distribution. Argentina, Bolivia , Chile .

Figures

FIGURE 25. Mortoniella collegarum (Rueda & Gibon), male genitalia: A—lateral; B—segment IX and tergum X, dorsal; C— dorsal phallic spine, dorsal.