Culoptila Mosely 1954 : 336

Blahnik, Roger J. & Holzenthal, Ralph W., 2006, Revision of the genus Culoptila (Trichoptera: Glossosomatidae), Zootaxa 1233, pp. 1-52 : 7-10

Culoptila Mosely 1954: 336

Type species: Culoptila aluca , original designation.

As discussed by Mosely (1954), the most distinctive feature of Culoptila is the modification of the tegulae of males. The tegulae are moderately to greatly enlarged in most species and cover an extensible glandular structure, which Mosely (1954) aptly described as being concertina­like. The length of this glandular structure varies among species and is difficult to compare directly, since it is only fortuitously expanded during the clearing of some specimens ( Figs. 4–8 ). In a few species, most especially C. thoracica ( Fig. 5 ), the tegulae are so enlarged that they affect the shape of the thorax, which is consequently very narrowed anteriorly. Despite this, the possession of modified tegulae and associated glands is not completely diagnostic for the genus, since a few species either lack these structures, or they are minimally developed and inconspicuous. An additional character discussed by Mosely (1954) as diagnostic for Culoptila is the structure of the ventral process of abdominal segment VI ( Fig. 28 C). The process is short, rounded to subtruncate apically, and unusual in that the posterior margin is only narrowly attached to a sclerotized, diagonal apodeme (present on sternum VI of all protoptilines). The anterior part of the ventral process sits in a small depression, so that it is not immediately apparent that the process is only narrowly attached, and thus it is not actually as peculiar appearing as in the diagrammatic illustrations of Mosely (1954).

Culoptila is further characterized by the male genitalia. A distinctive character is the apparent absence of a sternum IX. In a few species it is obvious that the ventral part of tergum IX is reduced to a very narrow, membranous band that subtends the phallobase. Probably, this occurs in all species, even when the membranous connection is not obvious. A similar reduction of the sternum occurs in the Antillean genera Campsiophora , Cariboptila , and Cubanoptila , and also occurs in the genus Tolhuaca ( Robertson & Holzenthal 2005) . Also characteristic of Culoptila is a projecting tergum X with a pair of ventrolateral processes. Tergum X varies greatly in length and shape among the different species and is often nearly diagnostic in and of itself. Perhaps the most unusual and diagnostic structure of the genitalia is the phallobase, which consists of a large inflated bag, open posteriorly, often nearly membranous in appearance, with a more or less rounded opening on the anterior or anteroventral margin through which the sperm duct probably enters the chamber. On its ventral surface is a pair of reduced inferior appendages, which are fused to the structure (absent in Culoptila cantha and C. plummerensis , n. sp.). It is notable that neither Ross (1938) nor Denning (1965) chose to illustrate the inflated phallobase as part of the genitalia, although it was discussed in their species descriptions. Although Mosely (1954) clearly illustrated the structure, he also did not consider it part of the phallic apparatus, but instead referred to the 2 internal spines as the “penis and penis sheath.” In some species only a single internal spine is found. The phallobase has a sclerotized, extending, posterodorsal apex, varying in shape, length, and the angularity of its inflection among the different species. The phallobase also often has a narrow sclerotized ridge running along the dorsal and ventral margins, which helps to give the overall structure a defined shape and size. This sclerotized ridge is more noticeable in some species (and probably also some specimens) than in others, and appears to be absent in some species. In dorsal or ventral views the phallobase of some species, particularly those with dorsal and ventral sclerotized ridges, shows varying degrees of lateral compression.

Another diagnostic feature of the phallic apparatus is an apical structure of variable sclerotization, which we have interpreted as the phallotremal sclerite. This fairly large structure is sometimes faintly sclerotized and difficult to see, or obscured by other structures. The overall structure is broadly tubular or trough­like, usually with 2 curved, finger­like, more prominently sclerotized apicodorsal projections. Because the structures of the phallotremal sclerite are often difficult to see, they may not always be precisely and accurately rendered in the accompanying illustrations. Generally, these are not features that a person identifying Culoptila is likely to focus on and, for most species, the phallotremal sclerite is not discussed in the species diagnoses or descriptions.

Adult. Forewing length 2.0– 3.8 mm, females slightly larger than males. Coloration from pale to dark brown, appendages usually paler. Anastomosis of forewing complete and nearly linear, usually marked by pale venation, sometimes with overlying whitish band of setae, or a whitish setal spot at the arculus. Forewing ( Fig. 9 A) with forks I–IV present, fork V absent; fork II sessile or petiolate; Cu1 incomplete, not reaching wing margin; Cu2 thickened, with row of stiff setae; 3A apparently absent (or possibly weakly developed). Hind wing ( Fig. 9 B) with only forks II and III present; crossveins absent (or possibly very weakly developed). Tegulae of males usually enlarged (minimally or not modified in some species) ( Figs.4–8 ), either flattened or inflated and rounded; ventrally with glandular structure of variable development, often elongate and concertina­like. Mesothorax unmodified or narrowed anteriorly (in species with greatly enlarged tegulae). Mesoscutum short and heart­shaped, or elongate and narrowed anteriorly (in species with greatly enlarged tegulae); scutellar warts small, ovoid, contiguous with mesoscutellum. Sternum VI of both males ( Fig 28 C) and females ( Fig. 16 A) with short, apically rounded or subtruncate ventral process; process only narrowly attached posteriorly to sclerotized segmental apodeme.

Male genitalia ( Fig. 11 ). Tergum IX with ventral margin usually rounded, occasionally acutely narrowed; sternum IX absent. Tergum X with apex variably developed, acute, truncate, or incised mesally; apicolaterally with sclerotized processes; processes setose, usually mesally curved apically. Preanal appendages absent. Inferior appendages fused to ventral surface of phallobase, usually short and linear, sometimes more elongate and curved mesally, apparently absent in C. cantha and C. plummerensis . Phallobase very large and rounded, weakly sclerotized (apparently membranous), with small rounded aperture in anterior or anteroventral margin; posterodorsally with sclerotized, projecting apex of variable development. Phallic spines 1 or 2, of variable length and development. Phallotremal sclerite fairly large, but often weakly sclerotized and inconspicuous, usually with more conspicuously sclerotized, paired, fingerlike posterodorsal processes.

Female genitalia. (Females unknown for many species). Segment VIII usually short and synscleritous ( Fig. 16 A, B), deeply incised midlaterally on posterior margin. Tergum IX short, with pair of elongate, narrow apical cerci; sternum IX very short. Vaginal apparatus with distinctive, elongate, sclerotized, keyhole sclerite. Extraordinarily, as in Figs. 23 A, B ( C. hamata ), with segment VIII not synscleritous and with tergum IX narrowed and elongate.

Figures

FIGURE 9. Culoptila hamata, new species, wings. 9 A—forewing; 9 B—hind wing.

FIGURES 4 – 8. Head, mesothorax, and tegular structures, dorsal. 4 — Culoptila hamata, new species. 5 — Culoptila thoracica (Ross). 6 — Culoptila aluca Mosely. 7 — Culoptila cantha (Ross). 8 — Culoptila moselyi Denning.

FIGURES 27 – 28. Male Genitalia. 27. Culoptila moselyi Denning: 27 A—lateral; 27 B—ventral. 28. Culoptila nahuatl Flint: 28 A—lateral; 28 B—ventral; 28 C—ventral process of sternum VI, lateral.

FIGURES 15 – 16. Culoptila bidentata, new species. 15. Male genitalia: 15 A—lateral; 15 Bventral. 16. Female genitalia: 16 A—lateral; 16 B—ventral.

FIGURES 10 – 12. Male genitalia. 10. Culoptila acaena Bueno­Soria & Santiago­Fragoso: 10 Alateral; 10 B—ventral. 11. Culoptila aluca Mosely: 11 A—lateral; 11 B—ventral. 12. Culoptila amberia Mosely—lateral.

FIGURES 22 – 23. Culoptila hamata, new species. 22. Male genitalia: 22 A—lateral; 22 B—ventral. 23. Female genitalia: 23 A—lateral; 23 B—ventral.