Citralla St Laurent & Kawahara

Laurent, Ryan A. St & Kawahara, Akito Y., 2019, Reclassification of the Sack-bearer Moths (Lepidoptera, Mimallonoidea, Mimallonidae), ZooKeys 815, pp. 1-114 : 19-22

Citralla St Laurent & Kawahara gen. n. Figs 115-117, 118, 119, 120

Type species.

Trogoptera rumina Druce, 1894: 355, by present designation.

Etymology.

The name for this new genus is derived from citrus (Latin) referring to the lemon-yellow coloration of the type species of rumina , the only recognized species in the genus. The name is feminine.

Diagnosis.

This new genus can be recognized by the following combination of characters: bright yellow coloration with gray and pink shading on the tornal region of the forewing and anal angle of the hindwing. The postmedial line of the forewing is faint, crenulate, and incomplete, existing only apically, as a small splotch halfway across the wing, and along the tornal shading. The hindwing displays similar maculation. Ventrally, the antemedial area of the forewing is shaded gray and pink, making Citralla and Zaphanta the only Mimallonidae genera with completely shaded antemedial regions of the ventral surface of the forewings. Citralla , however, lacks the ventral antemedial line present in Zaphanta . The prothoracic tibia has a prominent tuft of pink scales that is seen nowhere else in Mimallonidae . The male genitalia are simple, but unique in the absence of gnathos and transtilla projections, and by the simple triangular uncus and narrow valvae. The phallus is nondescript and largely similar to that of Lacosoma . The female genitalia are most similar to the related Vanenga , but display narrower papillae anales, ostium bursae, and ductus bursae. In Vanenga the confluence of the ostium bursae and ductus bursae is almost as wide as segment VIII, but in Citralla this part of the ductus bursae is only about one quarter the width of VIII, compare Figs 57, 119.

Apomorphies.

Combination of the following characters: (1) Gnathos reduced to narrow bars below uncus which lack both mesal extensions and subuncus projections typical of related genera ( Lacosoma and Vanenga ); (2) Simple, smooth, triangular uncus and narrow valvae (relative to sharply triangular or extremely narrow uncus of Lacosoma and Vanenga ).

Description.

Male.Head: Gray-brown, eyes very large, occupying more than two-thirds area of head, bordered posteriorly by dark scales; antenna coloration light tan, antenna bipectinate to tip, distalmost 10-12 pectinations significantly shorter; labial palpus three segmented, but segments difficult to discern due to compact scaling. Thorax: Coloration light yellow with scales along posterior prothoracic margin and junc tion with abdomen very faint pink and gray, ventrum pale gray. Legs: Coloration variable, prothoracic leg: femur light purple-gray, tibia yellow with light gray scales before juncture with tarsus, prominent tuft of pink scales present on inner margin of tibia apex, tarsus yellow. Mesothoracic leg: femur and tibia light gray, tarsus yellow with some gray scaling apically. Metathoracic leg: all segments predominantly yellow with some gray scaling at terminus of tibia and apex of tarsus. Tibial spurs elongate, narrow, dorsally covered in scales, ventral surface and tip naked, length roughly half length of first tarsal segment. Forewing dorsum: Forewing length: 9-14 mm, avg: 11 mm, wingspan: 19-27 mm, n = 16. Triangular, margin nearly straight. Ground color light yellow. Antemedial faint, pink, irregular, antemedial area may be slightly suffused with pink; preapical postmedial line irregular, incomplete, existing only near tornus, apex, and halfway across length of wing as single splotch. Postmedial line outwardly shaded with gray and pink, particularly along tornus where pink suffusion reaches wing margin. Discal mark present as light gray ovoid splotch. Fringe checkered off-white and orange-brown, slightly crenulate. Forewing ventrum: Nearly identical to forewing dorsum, but antemedial line absent and antemedial area completely shaded by pink and gray, discal spot more pronounced. Hindwing dorsum: Coloration, patterning as for forewing dorsum, but discal mark faint or absent, antemedial line absent. Hindwing ventrum: Following same pattern as forewing ventrum. Frenulum present as single bristle. Venation: Typical of Mimallonidae . Abdomen: Dorsal coloration as for thorax, but slightly darker. Genitalia: (Fig. 118) n = 3. Vinculum ovoid, ventrally inwardly notched. Uncus simple, triangular, ventrally membranous. Gnathos and transtilla absent, but sclerotized bars extend downward from uncus/tegumen junction. Valvae narrow, triangular, simple; base of valvae extend centrally above vinculum base such that valvae cannot be fully spread. Juxta fused to phallus, encircling it, extending dorsally above phallus as flattened process. Phallus cylindrical, basally truncated. Female.Head: As for male, but antennae smaller overall. Thorax, Legs: As for male. Forewing dorsum: Forewing length: 11.5-15.0 mm, avg: 13.8, wingspan: 26-30 mm, n = 7. As for male, but slightly broader overall. Forewing ventrum: As for male, but slightly broader overall. Hindwing dorsum: As for male, but slightly broader overall. Hindwing ventrum: Following same pattern as forewing ventrum. Frenulum as multiple bristles. Abdomen: As for male, but more robust. Genitalia: (Fig. 119) n = 1. Tergite VIII forms smooth, thickened posteriorly directed arch, mesally with cup-like indentation at dorsal base of papillae anales. VIII weakly sclerotized laterally. Apophyses anteriores thick, truncated distally, roughly half length of apophyses posteriores which are outwardly bent halfway along length. Lamella ante- and postvaginalis poorly preserved, but weakly sclerotized without distinguishing features. Ductus bursae long, narrow, about three times the length of VIII-X, ductus widest at convergence with ostium bursae, but remaining very narrow along remainder of length. Corpus bursae small in length in comparison to elongated ductus bursae and large papillae anales, shape balloon-like. Papillae anales narrow, elongated, ventrally angled such that apical ridges of papillae anales and opening between them situated ventrally in nearly same plane as ostium bursae.

Remarks.

Citralla is here described for the unique species C. rumina comb. n., which is distributed from Guatemala to southeastern Brazil. Further taxonomic investigations into the various populations of C. rumina will undoubtedly reveal several cryptic species, as we have observed slight external morphological distinctions in populations in Southeastern Brazil and the Amazon, in comparison with topotypical material from Panama and nearby Costa Rica.

Ongoing molecular phylogenetic work which includes Citralla consistently places this genus sister to Vanenga , which together form a clade sister to Lacosoma (St Laurent in prep.). Morphological analyses are less consistent in placement, with our morphological analyses recovering Citralla sister to (unconstrained ML analysis) or nested within Lacosoma (constrained ML and MP analyses). Regardless, tribal placement of the new genus is confidently in Lacosomini . The substantial reduction of the gnathos and juxtal configuration are most similar to those of both Lacosoma and Vanenga than to any other know Mimallonidae genus. But the uncus shape and pink scale tufts on the forelegs are unique to C. rumina . The larvae of C. rumina (Fig. 120) have been reared and photographed by Janzen and Hallwachs (2017), revealing morphology remarkably similar to various species of Lacosoma , two species of which have been reared by the first author ( St Laurent and Carvalho 2017b, St Laurent et al. 2017). In particular, the striated appearance of the head and prothoracic shield, as well as the less rugose anal plate are largely consistent with Lacosoma as opposed to the more uniform coloration and generally more robust anal shield of other groups such as Mimalloninae and Cicinninae. We therefore, consider these characters as additional information supporting our decision to place Citralla within the Lacosominae: Lacosomini .

According to Janzen and Hallwachs (2017), the host plant of C. rumina in Costa Rica is Eugenia salamensis Donn. Smith ( Myrtaceae ). Myrtaceae is a host plant family that is frequently a larval resource for Mimallonidae (St Laurent et al. 2018).