A taxonomic review of Eucalantica Busck (Lepidoptera, Yponomeutidae) with descriptions of six new species

Abstract The New World genus Eucalantica Busck, 1904 is reviewed. It comprises seven species, six of which are described as new: Eucalantica costaricae Sohn & Nishida, sp. n., Eucalantica ehecatlella Sohn & Nishida, sp. n., Eucalantica icarusella Sohn & Nishida, sp. n., Eucalantica powelli Sohn, sp. n., and Eucalantica pumila Sohn, sp. n., all five from Costa Rica; Eucalantica vaquero Sohn, sp. n. from southern USA and Mexico. The type species, Eucalantica polita (Walsingham, 1881), is redescribed and a lectotype and two paralectotypes are designated. Illustrations and keys based on the forewing patterns and the genitalia of each sex are provided. Our review suggests that there remains an undiscovered high diversity of Eucalantica in the tropical highlands of Central America.


Introduction
The genus Eucalantica was proposed by Busck (1904) to account for differences of the type species Calantica polita Walshingham, 1881, from other Calantica Zeller, 1847, a junior homonym of Calantica Gray, 1825, whose replacement name is Niphonympha The genitalia slide numbers (GSN) are given for the dissected specimens with the suffix 'USNM' for USNM specimens, 'EMEC-JCS' for EMEC specimens and 'SJC' for INBIO specimens. Unmounted genitalia are stored in glycerin-filled, transparent envelopes which are attached with dissected specimens. Pinned specimens were examined under a Leica MZ APO stereoscope. Slide-mounted specimens were examined under a Leica LETTZ-DMRX microscope.
Terms for genitalia and wing venation follow Klots (1970) and Wootton (1979), respectively. The 7 th , 8 th , and 9 th abdominal segments are abbreviated as A7, A8, A9 respectively in the descriptions; the 7 th and 8 th sternite of females as S7 and S8.
Diagnosis. This genus is superficially similar to Thecobathra Meyrick, 1922, which also has a silvery white body and forewings, but differs from the latter in having a dark brown costal streak in forewing. The male genitalia of Eucalantica are distinguished from those of Thecobathra in having three or four spines on socii (none or one spine in the latter) and a lack of dentiform projections on phallus (present in the latter). The female S8 is entirely or almost entirely sclerotized in Eucalantica, but not in Thecobathra.
The female genitalia of those two genera are also different in the shape of the signum, if present: keel-like or discoid plate in Eucalantica, cruciform in Thecobathra. Description. When resting, Eucalantica moths lay their body parallel to the substrate with their forelegs extended forward (Fig. 5).
Head (Fig. 1). Vertex vestiture rough with white, piliform scales; frons dark brown. Antennae filiform, 3/5 as long as forewing; scape white, with brown pecten; pedicel and first two flagellomeres with two complete whorls of scales per segment, white dorsally, gray ventrally; the remaining flagellomeres with a dorsal cover of gray scales on anterior half, a complete whorl of gray scales on distal half. Labial palpus porrect, 1 st segment pale brownish gray, 1/4 as long as 2 nd ; 2 nd segment dark brown, with denser scales distad, as long as eye diameter; 3 rd segment white except dark brown on ventrobasal area, with white scale tufts dorsally, as long as 2 nd . Maxillary palpus 4 segmented. Proboscis devoid of scales, longer than labial palpus.
Thorax and abdomen. Tegula and mesonotum white. Foreleg lustrous dark brown dorsally, gray ventrally; epiphysis arising at middle. Midleg with coxa to tibia lustrous pale brown dorsally, silvery white ventrally; first tarsus dark brown dorsally, silvery white ventrally; the remaining tarsi brownish gray with dark brown ring on distal end. Hindleg silvery white, slightly tinged with pale brown ventrally. Th e forewings  white, elongate-triangular, costa straight, apex at anterior 1/3 of termen, obtuse-angled, termen oblique after apex; a black spot at the upper corner of discal cell; scattered black spots on the posterior 1/2 and distal 2/3; a brown or orange dorsal patch; however, the latter two are often reduced, depending on the individual. Th e forewing venation of Eucalantica ( Fig. 2) with pterostigma 2/5 of costa before R; Rs 1 and Rs 2 stalked; Rs 4 below apex; M 2 and M 3 at base closer than M 1 ; CuA1 directed to tornus; CuA 2 ending at posterior margin. Th e hindwing slightly broader than forewing, pale gray, darkened to apex and anterior margin, termen broadly round, apex narrowly round; venation ( Fig. 2) with Sc+R 1 ending at the middle of anterior margin; Rs directed to apex; M 1 , M 2 and M 3 evenly spaced; CuP close to 1A+2A. Abdomen silvery white, slightly tinged with pale brown on basal half; pleural lobe silvery white.
Male genitalia . Uncus linguiform, convex posteriorly, medially fused with tegumen; in four of the seven species, a pair of lateral humps present near apex; socii elongate, extended from ventrobasal area of uncus, with a row of 3-4 spines ventroterminally. Tuba analis with weakly sclerotized area ventrally ('subscaphium'), continuous to gnathos; gnathos as a transverse bulge below tuba analis, with narrow, band-like sclerotization along apical edge. Valva obovate or rectangular, setose on the posterior half of the ventral side, with species-specific groove or projections above basal sacculus. Vinculum narrower to saccus; saccus elongate. Aedeagus straight or bent medially; cornuti absent or as a zone of minute spinules.
Female genitalia . Papillae anales subtriangular. A pair of hairy humps on the distal margin of S8; interspace between the humps with dense, minute thorns, the thorny area extending above and below S8 humps. Segment S8 entirely or mostly sclerotized, sometimes posterolateral margins forming a semicircular fold (Figs 32 and 35, indicated by asterisk); depending on the species, with a pair of pits ( Fig. 35a) or semicircular depression (Fig. 31b) near ostium. Antrum digitate or bowl-shaped, with numerous minute thorns internally; thorny area extending caudally beyond ostium bursae. Ductus seminalis near a connection between ductus and corpus bursae; bulla seminalis as large as (in polita) or smaller than corpus or absent (in costaricae). Corpus bursae very fragile due to its thin wall; signum absent in two species, present in three species and shaped like a dentate keel or a small scobinate disk.
Species diversity. The distribution of Eucalantica as shown in this paper indicates a high diversity of the genus in the Central America. Three of the five Costa Rican species described in this paper were found in the high-elevation oak forests of Cerro de la Muerte region, indicating that multiple species can coexist in a single ecozone. Interestingly, there exists a different group of congeners in the high mountains of Heredia province. This pattern predicts more undescribed species of Eucalantica present along the montane systems of Costa Rica and other Central American countries.

Key to the adults of Eucalantica species including variants in forewing patterns
Note: External appearance is usually inadequate for species identification of Eucalantica. Whenever possible, examination of the genitalia is advised for reliable identifications of the species. Valva with a triangular mound above subbasal saccular region (Fig. 17c) (1881) did not state the exact type locality and the number of specimens for his description of Calantica polita. A male specimen from BMNH has a red-bordered round label written "Type". Two type specimens of C. polita from MCZ are duplicates by Walsingham which were sent to Chambers (Miller and Hodges, 1990). Therefore, all three specimens from BMNH and MCZ which hold "Type" label must be syntypes as Miller and Hodges (1990) already indicated. We formally designate a lectotype of C. polita amongst these specimens.   Diagnosis. This species externally resembles Euceratia castella Walsingham, 1881, among the described species of North America, but is easily distinguished from the latter in having a dorsal patch on forewings and by in lacking white annulations on the antennae.
Redescription (Figs 7-9). Forewing length 5.5-8mm (mean=7.19mm, n=58); basal 1/4 of costa dark brown; an oblique, bar-like, reddish brown patch on distal 1/3 of posterior margin, surrounded by black speckles; posterior suffusion reddish brown, as long as dorsal patch; posterior suffusion and/or dorsal patch lost and black specks peppering, depending on the individuals; a black spot at the end of discal cell; a black scale on each vein along termen; fringes white on basal half, grayish brown on distal half, or entirely white in some specimens. Hindwing anterior margin 2× longer than maximum width; fringe pale gray on basal half, white on distal half.
Host plant. The larvae feed on flowers and leaves of California Huckleberry, Vaccinium ovatum Pursh (Ericaceae) (Powell & Opler, 2009). In the USNM collection, there exist two specimens of E. polita reared from "rhododendron", possibly Rhododendron pacificum. These records, however, need to be confirmed. The host record "huckberry" from USNM must be an error for "huckleberry". The label data available from museum specimens indicate that the larvae are twig-borers, leaf-miners or leaftiers. The larvae of E. polita are primarily external feeders which web amongst inflorescences or young vegetative terminals of Vaccinium ovatum (Jerry Powell, personal communication). All records of the internal feeding larvae of E. polita are associated with "rhododendron", a host which is yet unverified.
Remarks. E. polita shows continuous variations in forewing patterns between two extremes which are very reduced (Fig. 8) or maculate throughout (Fig. 9). Those vari-ants coexist temporally and spatially, for which no taxonomic consideration is necessary. However, some of the variants can be confused with the new species described in this study. Walsingham (1881) illustrated an individual of E. polita whose forewings have only a dorsal patch and discal spot (Fig. 7). We found that this variant is predominant (ca. 87%) amongst the specimens examined in our study. The maculate variants were the rarest (ca. 0.7%). Diagnosis. This new species is superficially indistinguishable from some variants of E. polita. In such cases, examination of genitalia is necessary for reliable identification. E. costaricae differs from E. polita by the lack of lateral projections near the apex of the uncus in the male genitalia and in having a signum in the corpus bursae of the female genitalia.

Eucalantica costaricae
Description (Fig. 10). Forewing length 6.5-8mm (mean=7.48mm, n=9); posterior suffusion and dorsal patch absent; in majority of individuals, black spots scattered on distal and posterior half; fringes entirely white. In some specimens, all forewing pattern elements are lost except a discal spot. Hindwing anterior margin 3× longer than the maxium width; fringes entirely white.
Distribution. Costa Rica (high elevations of Cerro de la Muerte of the Talamancan Mountain Range in Cartago and San José Provinces).
Habitat. The adult specimens have been collected exclusively from the high elevation forests of Cerro de la Muerte where oaks are dominant below 3,300m (Zuchowski, 2007). See Nishida et al. (2002) for more details about the habitats. The second author (KN) observed one individual of this species resting on the underside of a leaf of Vaccinium floribundum Kunth (Fig. 1). Given the host association of E. polita with another Vaccinium, this plant is likely the larval host of E. costaricae.
Etymology. The new species is named after Costa Rica, where the type locality is situated. Diagnosis. This species is very close to E. icarusella in the shape of the dorsal patch of the forewing and in having entirely pale gray forewing fringes but differs from the latter by having most of the black dots sparsely scattered beyond the discal cell. Eucalantica ehecatlella is further distinguished from E. icarusella by the lack of projections near the apex of uncus in the male genitalia.
Female. unknown. Distribution. Costa Rica (Central Volcanic Range in Heredia Province). Etymology. The specific epithet is derived from 'Ehecatl', a god of wind in Aztec mythology and refers to the windy habitat where the new species was collected. Diagnosis. This species is superficially similar to E. costaricae, but differs from the latter in having a posterior suffusion on the forewings and narrower hindwings. In the genitalia, E. icarusella is distinguished from E. costaricae in having projections (Fig.  23a) near the apex of the uncus in the males and having a pair of pits (Fig. 35a) near ostium bursae in the females. Description (Fig. 11). Forewing length 5.3-7.9 mm (mean=7.07mm, n=9); costal streak dark brown, broadly spread basally; dorsal patch at the middle of posterior margin, dentiform, orange, with a black line on upper border; posterior suffusion on basal 1/2 of dorsal margin, orange, with an intermittent black line on upper border; black spots peppering in distal 3/4, denser to distal 1/3; fringes pale gray in basal 1/3, brownish gray in distal 2/3. Hindwing anterior margin 2.5× longer than maximum width; fringes pale gray.
Distribution. Costa Rica (high elevations of Cartago, Heredia and San José). Etymology. The new species is named after the Greek mythological character Ikaros (Icarus in Latin) and refers to the white forewing with scarlet dorsal suffusion resembling Icarus' waxy wings burnt down by sunlight. Diagnosis. This new species is similar to immaculate variants of E. polita ( Fig. 8) but differs from the latter in having posterior suffusion on entire dorsal margin of forewings. They are also distinguished by the male genitalia, i.e. triangular projection on valva closer to sacculus in E. powelli, and also by the female genitalia, i.e. the presence of posterolateral semicircular pleats (indicated with an asterisk in Fig. 32) in E. powelli. Description (Fig. 12). Forewing length 7.0-10.0 mm (mean=8.48mm, n=5); dorsal margin with a row of black dots from the base to the basal 1/3; posterior suffusion on distal 2/3 of dorsal margin, sinuate, orange, with an intermittent black line on upper boarder; terminal line on posterior half of termen, black, intermittent; fringes white in basal half, reddish brown in distal half.
Female genitalia (Fig. 32) (2 preparations examined). S8 slightly oblique laterally, weakly sclerotized, with a pair of setose humps posteromedially; interspace between S8 humps with minute thorns; a pair of semicircular pleats lateroposteriorly (indicated with an asterisk in Fig. 32). Apophysis posterioris 4× longer than apophysis anterioris excluding basal Y-fork; longer branch of Y-fork 3× longer than shorter branch, 2.5× longer than apophysis anterioris. Ductus bursae 2× longer than corpus; antrum in posterior 1/6 of ductus bursae, cylindrical, with minute thorns on inner wall (Fig. 32a) Diagnosis. This new species is easily distinguished from all other species of Eucalantica by its smaller size and in having a triangular, dark brown dorsal patch on the forewings. The male genitalia of E. pumila is similar to E. costaricae, but spines on the socii and the aedeagus is slender in the former.
Description (Fig. 13). Forewing length 5.8 mm (n=1); costal streak on basal 1/10 of costal margin, black; dorsal patch subtriangular, dark brown, upper border extended to the lower side of the discal cell; terminal line with three dark brown dots between veins. Hindwing anterior margin 2.2× longer than maximum width, pale gray except dark gray apical area.
Female. unknown. Distribution. Costa Rica (only known from the type locality). Etymology. The specific epithet is derived from the Latin pumilus, meaning "little", and refers to its small size relative to other Eucalantica. Diagnosis. This new species is superficially indistinguishable from some variants of E. polita and in such cases, examination of the genitalia is necessary for a reliable identification. E. vaquero is also similar to E. costaricae in having a reduced dorsal patch on the forewings but differs from the latter by having the fewer black spots on the forewing, mainly around the CuP fold. The male genitalia of E. vaquero differ from ones of E. polita and E. costaricae in having a bulge on apex of the uncus and stouter saccus. In the female genitalia, E. vaquero is distinguished from the latter two in having keel-like signum in the corpus bursae.
Distribution. USA (New Mexico, Arizona) and Mexico. Etymology. The species name vaquero is a noun in apposition, meaning the Mexican cowboy, and refers to the distribution range of the new species roughly matching with the regions under 'vaquero' traditions. and Philip Perkins (both from Museum of Comparative Zoology, Harvard University, Cambridge), Kevin Tuck (Natural History Museum, London), and José Montero and Alvaro Herrera (both from INBio, San Jose) for allowing him to study the institutional collections under their responsibility. Fieldwork and museum visits by the first author were supported by the Explorers Club Washington Group's Exploration and Field Research Grants (2007) and the Ernst Mayr Grants (2008).