Itauara Mueller , 1888

Robertson, Desiree R. & Holzenthal, Ralph W., 2011, Revision of the Neotropical caddisfly genus Itauara Mueller, 1888 (Trichoptera, Glossosomatidae), ZooKeys 114, pp. 41-100 : 42-46

Genus Itauara Mueller, 1888

Itauara Müller, 1888: 275 [Type species: Antoptila brasiliana Mosely, 1939, subsequent selection by Flint, Holzenthal, and Harris 1999].

Antoptila Mosely, 1939: 219 [Type species: Antoptila brasiliana Mosely, 1939, original designation] Flint, Holzenthal, and Harris 1999, to synonymy.

Notes

The genus Itauara can be identified by features of the male genitalia. The phallic apparatus consists of a sclerotized dorsal sheath covering a very membranous ventral portion, an apparent posterior extension of the phallobase or phallicata. Rarely, the phallicata is tubular or separated from the phallobase by a membranous portion. In some species, this sclerotized dorsal sheath seems to detach from the ventral membrane apically to reveal a single dorsomesal process or spine (e.g., Itaura amazonica ). Mortoniella has a similar dorsomesal process or spine, but in Mortoniella it arises internally from the phallobase, whereas in Itauara it arises dorsobasally, as an extension of the phallicata. In several species the sheath produces a dorsolateral flange-like process, although this character is not diagnostic for the genus. Another genitalic feature characteristic of Itauara is an extremely reduced phallobase. In most species, the phallobase is barely visible, consisting of a small, very lightly sclerotized or an entirely membranous structure. The genera Mastigoptila and Canoptila display similar reductions or absences of the phallobase, but can easily be separated from Itauara by other genitalic characters: Mastigoptila has an elongate, whip-like process arising from the membranes of the phallocrypt; Canoptila has highly membranous digitate parameres. When present (they have been lost in many species), the inferior appendages are rather distinct for Itauara , consisting of a single or apically bifid process produced mesally and fused to the phallobase ventrobasally. This inferior appendage process articulates with the base of the phallobase and in doing so, is capable of pivoting downward (Fig. 13A and inset). All species, except in Itaura brasiliana , have rather elongate, sclerotized, rod-like parameres, whose shape varies greatly among species. In many species these parameres arise ventrobasally from the phallobase, with which they appear to articulate. As the inferior appendage process is absent in those species, it is possible that the parameres have taken on a clasper-like function.

The forewing venation of Itauara is most similar to that of Cariboptila and Canoptila , with apical forks I–III and a lack of 3A (Fig. 2A, B). A single species also possesses apical fork IV (Fig. 2C). Canoptila can be differentiated from Itauara by having stout setae occurring below Cu2 whereas in Itauara the setae occur along the vein. Cariboptila can be differentiated from Itauara by the presence of a short discoidal cell, that of Itauara being long. The lengths of the apical forks vary among species. The hind wing venation of Itauara is variable, with either apical forks II, III, and V (Fig. 3C); II and V (Fig. 3A); III only, or II only (Fig. 3B).

Adult. Body, wings, and appendages pale or tawny brown, often intermingled with rufous or golden hairs, tibia and tarsi yellowish brown (Fig. 1). Wings often with partial white transverse line along anastomosis not reaching costal margin, or often with conspicuous white spot at the arculus (Fig. 1). Head broader than long, vertex rounded, with pair of small anteromesal setal warts or with large anteromesal setal wart, either 1 distinct pair or 1 divided pair of suboval anterior setal warts, small or large suboval posterior warts, suboval or triangular and bulging posterolateral setal warts. Ocelli present. Antennal scape less than or equal to 2 times the length of pedicel. Maxillary palps 5 segmented, 1st and 2nd segments short; 2nd segment bulbous; last 3 segments each nearly same length as 1st and 2nd segments combined. Prothorax with 2 large subtriangular or suboval pronotal setal warts. Mesothorax wider than long, without apparent tegular glands; mesoscutum with pair of suboval anteromesal setal warts, suboval posterolateral warts; mesoscutellum sparsely setose, without distinct setal warts. Forewing (Fig. 2) usually relatively narrow, with margins nearly parallel, occasionally narrowed past anastomosis or much reduced, apex acute, subacute, or rounded. Male occasionally with callosity present in apical costal region of forewing. Forewing venation incomplete, with apical forks I, II, and III present, or rarely I–IV present; Sc and R1 distinct along their entire lengths; fork I sessile or only slightly petiolate with extremely short stem; fork II petiolate or sessile, when petiolate, stem length variable; fork III petiolate, stem variable in length; Cu1 complete, reaching wing margin; Cu1 and Cu2 intersecting near anastomosis; row of erect setae present along Cu2; A3 absent; crossveins forming a relatively linear transverse cord; discoidal cell longer than Rs vein. Hind wing (Fig. 3) margins nearly parallel, tapering only slightly past anastomosis, or narrowed, scalloped past anastomosis, or much reduced; venation variable, either with apical forks II, III, and V present, II and V present, III present, or II present; Sc and R1 fused basally or converging near wing margin; A2 absent. Tibial spurs 1,4,4, rarely 1,3,4, foretibial spur extremely reduced and hairlike. Sixth sternal process present, short and digitate or thumb-like and prominent, apex rounded or attenuate and pointed, usually associated with oblique apodeme posteriorly.

Male genitalia. Segment IX usually rather broad, anterior margin rounded, posterolateral margin without lateral process or lobes in lateral view; tergum IX usually not well developed, simple, and without processes; sternum IX without modification, except in Itaura brasiliana , which bears 2 pairs of elongate, seta-like processes. Tergum X incompletely fused to tergum IX ventrolaterally or rarely ( Itaura amazonica ) completely fused and indistinct from tergum IX, shape extremely variable; dorsomesal margin may be simple without processes, bifid apicomesally, with a single broad, plate-like process, or irregular with several small processes; dorsolateral margin either a simple structure without processes, or more commonly with small paired lobes, elongate, down-turned, finger-like process, or irregular setose processes; ventrolateral margin with paired elongate or broad flange-like processes directed ventrally and sometimes anteriorly, or with one or more irregular, paired, setose, digitate lobes directed posteriorly. Inferior appendages either present or absent; when present, consisting of single or apically bifid process produced mesally, broadest at base and fused to phallobase ventrobasally. Parameres present except in Itaura brasiliana , arising either ventrobasally from phallobase or laterally from endotheca, sclerotized, shape variable. Phallobase extremely reduced and difficult to discern. Phallicata a sclerotized dorsal sheath covering membranous ventral portion, sometimes receding to a single dorsomesal process arising dorsobasally from phallobase, phallicata occasionally with dorsolateral flange, or occasionally with dorsomesal spine arising posteriorly to phallobase. Endophallus highly membranous, enlarged and convoluted when evaginated, occasionally bearing apical spine-like sclerites and processes.

Female genitalia. (Females unknown for many species.) Truncate posteriorly, not extensible. Abdominal segment VIII short, synscleritous, posterolateral margin slightly incised. Segments IX and X closely associated, with pair of small digitate cerci dorsolaterally.