A new Antaeotricha species from Florida sandhills and scrub (Lepidoptera, Depressariidae, Stenomatinae)

Abstract Antaeotricha floridella sp. n. is described and diagnosed from the closely similar Antaeotricha albulella (Walker). The species is distributed in xeric sandhill and scrub habitats in peninsular Florida, USA, and larvae feed on Quercus species. Keys are given for pale-winged Stenomatinae and similar Gelechioidea based on external characters and genitalia.


Introduction
The genus Antaeotricha Zeller, 1854 (Lepidoptera: Depressariidae: Stenomatinae) is endemic to the New World and includes nearly 400 species, mostly in the Neotropics (Becker 1984). Twenty Nearctic species are known (Ferris 2013), including the one described below. Duckworth (1964) comprehensively revised the Nearctic Stenomatinae, and four species were recently described from the southwestern United States (Ferris 2010(Ferris , 2012(Ferris , 2013. The second author (TSD) discovered the presently described species by dissection, as it is externally very similar to the widely distributed A. albulella (Walker, 1864) (more often called by its junior synonym A. vestalis (Zeller, 1873) [Becker 1981]). The search of other collections by JEH yielded more specimens, including ones overlooked by Duckworth. The species description necessitates a revised key to pale-colored Nearctic Stenomatinae. The species is known only from xeric habitats in peninsular Florida. This pattern of endemism of species in Florida sandhills is common among other orders of insects and arthropods but is infrequent in Lepidoptera (Deyrup 1989), so the addition of another endemic species is significant.
Stenomatinae are diagnosed by the presence of thickened, apically bifid or multifid setae on the valvae of the male genitalia (Hodges 1998) (Fig. 10: b s). The subfamily has been placed in various gelechioid families, including Oecophoridae, Elachistidae, and most recently in the resurrected Depressariidae (Heikkilä et al. 2014) based on pupal morphology and weak molecular evidence. Depressariid pupae share lateral condyles between abdominal segments. Unlike most other depressariids, stenomatines have a gnathos that is apically smooth, not scobinate or spiculate.
Antaeotricha as a genus is diagnosed by the presence of a thumb-like process on the costa of the male valva (Fig. 14: th) and by the reduction of the anterior apophyses of the female ovipositor ( Fig. 18: a a) (Duckworth 1964). Most species have white or brown wings with some contrasting maculation, usually the postmedial line, but often reduced to one or two spots on the discal cell. The newly described species has totally immaculate white wings.
The two previously published keys to Antaeotricha are based on wing pattern (Barnes and Busck 1920) or genitalia (Duckworth 1964). We provide two revised keys based on maculation and genitalia that treat pale-winged species of Antaeotricha and similar gelechioids.

Materials and methods
Dissection of genitalia follows Robinson (1976): abdomens were macerated in hot 10% aqueous KOH, brushed clean in water, stained with Chlorazol Black, and slide-mounted in Euparal or stored in glycerin. Photographs were taken with 1) a Canon PowerShot Pro1 and 2) the Auto-montage Pro 5.01 system (Synoptics Ltd.) using a JVC digital camera and Leica Z16APO lens (FSCA). Habitus photographs were taken over standard 18% gray card under tungsten or fluorescent LED lights, and genitalia photographs were lit from above and below. Postprocessing was limited to 1) stacking images with Auto-Montage and 2) using Adobe Photoshop Elements 11 to standardize the gray (for habitus) or white balance (for slides) and the Auto Contrast function for some genitalia images. The map was made with Diva-GIS version 7.5.0.0 using a county-level shape file available from the website (www.diva-gis.org) and a CSV file of georeferenced decimal-degree coordinates.

Repository abbreviations are as follows ABS
Archbold Diagnosis. Dorsally, the forewings of Antaeotricha floridella are immaculate white without any trace of a black spot at the distal end of the discal cell, and the hind wings are always pale gray. Antaeotricha albulella has one or two small black dots on the forewing at the distal end of the discal cell (Figs 7-9). A spot is usually visible under magnification even when worn, but some fresh specimens lack the spot entirely. The hind wings of A. albulella are usually white, but some specimens have pale gray hind wings. Antaeotricha osseella (Walsingham, 1889) (Fig. 6) and A. unipunctella (Clemens, 1863) are pale tan, ochreous or straw-colored with one or two black spots on the distal end of the forewing discal cell. The Western species A. thomasi (Barnes & Busck, 1920) and A. utahensis Ferris, 2012 are larger (forewing length ≥10 mm) and creamy white. Antaeotricha utahensis has a glossy sheen with small, scattered brown scales (Ferris 2012).
The most obvious genitalic difference between A. floridella and A. albulella is the shape of the gnathos. In A. floridella, the lobes of the gnathos are flat, round-tipped, and close together, with the length of each lobe not longer than the common stalk. This is like the shape in A. osseella and A. unipunctella, but in A. albulella (Figs 13,15), the lobes of the gnathos are acute and widely spaced, with a U-or H-shaped embayment between them, and their common stalk is shorter than each lobe, almost non-existent. The gnathos of A. thomasi and A. utahensis is not bifid. The anellus of A. floridella has two lobes on each side, and the dorsal (interior) lobe bears a few chaetae that are shorter than the lobe itself. In A. albulella and A. osseella, the interior lobes of the anellus bear more robust chaetae that are about as long as the lobe itself. Some specimens of A. albulella have sub-apical chaetae; these are not present in A. floridella, although some specimens have a fine sub-apical seta. The genitalia of A. floridella are similar to those of A. unipunctella depicted by Barnes and Busck (1920, Pl. XXIX fig. 3). Floridian specimens of A. unipunctella have two anellar lobes rather than the four figured by Barnes and Busck (1920) and Duckworth (1964). Antaeotricha thomasi and A. utahensis have no anellar lobes. In the female genitalia of A. floridella, sternite VIII consists of two flat setose pads that are broadly joined mesally and not bordered by pockets on the anterior margin. In contrast, these pads in A. albulella distinctly protrude out of the plane of the sternite and are partly divided by an anterior emargination (Fig. 18). There is a shallow pocket in the membrane between each protrusion and SVIII. These protrusions are diagnostic for A. albulella and are obvious in the undissected lectotype specimen. The ductus bursae of A. floridella is slightly longer than the corpus bursae, whereas A. albulella has a ductus bursae as long as the corpus bursae. The signum of A. floridella varies in shape but is generally rhombiform or trapezoidal, being at least as wide or wider mesally than at either end, and it lacks a central denticle. In A. albulella, A. osseella, and A. unipunctella, the signum is more or less arachiform (peanut-shaped), being mesally constricted or at least linear in A. unipunctella. In those species, the signum frequently has a central denticle in addition to scattered lateral denticles, which is especially well-developed in A. osseella (Fig. 19). The central denticle is absent in A. floridella. The signum of A. thomasi and A. utahensis is differently shaped (cruciform in the former and hexagonal in the latter).
Description. Head (Fig. 5). Vertex white; frons white and laterally pale brown. Labial palpi with second segment laterally pale brown, mesally white; apical segment all white. Ocelli absent. Antenna white on scape, pedicel, and basal flagellomere, distal flagellomeres brown; male sensilla as long as width of flagellum; female sensilla short.
Wings (Figs 1-2, 4). Mean forewing length of males: 6.6 mm, range 6.0-7.0 mm (n = 26); of females: 7.6 mm, range 6.5-8.5 mm (n = 15). Forewings with anterior and posterior margins parallel. Eleven veins arising separately from cell; Sc, R 1 , Rs 1-4 , M 1-3 present; CuA 1 and CuA 2 from common point at corner of cell; CuP tubular in distal 2/5; 1A+2A forked at base. Forewings dorsally matte white with no trace of black discal spots or other maculation, or if greased, pale lemon yellow; costa proximally pale brown, distally white. Ventral side pale grayish yellow. Hind wing venation: Sc+R 1 present; Rs 1 stalked with M 1 1/4 their length; M 2 present; M 3 and CuA 1 from common point at corner of cell; CuA 2 from well before end of cell; CuP, 1A+2A, 3A present. Hind wings pale gray on both sides, fringe white; male with tuft of short hairlike scales from base of discal cell on dorsal side. Male retinacular hook present; female frenulum double or triple.
Abdomen. Uniformly white, without androconia or otherwise modified scales.
Male genitalia (Figs 10-12). Uncus slender, distally bulbous and truncate. Gnathos with two lobes, flattened and broadly pointed, lobes as long as common stalk, set closely. Vinculum broadly concave ventrally. Distal half of valva narrowly rounded and membranous; medio-central extension of valva ("harpe" of Duckworth 1964) mitten-shaped, with "thumb" on costal half parallel-sided, twice as long as wide, bearing long, curved, bifid setae, and with lateral half broadly triangular, with short, straight, bifid setae. A narrow, setiferous ridge present basal of thumb. Each half of anellus with two lobes: ventral (exterior) lobe with long setae, dorsal (interior) lobe with a few short chaetae restricted to apex, no longer than the lobe. Phallus without cornuti; with (specimens from southern Florida) or without low subapical tooth.
Ostium bursae in middle of sternum VII. Lamella antevaginalis a narrow, curved band. Lamella postvaginalis with a broad, triangular extension covering ostium. Ductus bursae as long or longer than corpus bursae, not sclerotized, leading straight into corpus bursae or with a half-twist. Ductus seminalis from near posterior end of ductus bursae. Corpus bursae pyriform. One signum (Fig. 17) situated halfway along corpus bursae, bulged inward, roughly rhombiform with transverse axis the longer; shape variably ovoid, rhomboid, or with anterior side slightly more acute than posterior; denticles present on each half, without central denticles along mesal suture or in center.
Etymology. The specific epithet is an adjective derived from the state of Florida, diminutive like congeners.
Distribution. The type locality is in Ocala National Forest (Marion County, Florida, USA) south of Lake Kerr in sandhills dominated by longleaf pine (Pinus palustris Mill.) (Fig. 20). The known distribution is peninsular Florida, including ten counties: Citrus, Flagler, Highlands, Hillsborough, Lake, Marion, Martin, Osceola, Pasco, and Putnam.
Ecology. Antaeotricha floridella has been reared on leaves of Quercus geminata Small (sand live oak) and Q. minima (Sarg.) (dwarf live oak; identified with "?"). D.H. Habeck reared a specimen on Galactia regularis (L.) (downy milkpea). Adults have been collected April 10-October 30.   (Zeller, 1873) with A. albulella (Walker, 1864), and he remarked that the lectotype of A. albulella and the available specimens of A. vestalis all had black discal spots. Zeller (1873) stated that the type of Cryptolechia vestalis had white forewings "ohne jede Zeichnung" (without any marking), but the hind wings are white like the forewings. The lectotype specimen, deposited in the Museum of Comparative Zoology (Cambridge, MA, USA) is a female from Texas. Its forewings have faint black discal spots, and sternum VIII has the typical setose protuberances, which are visible without dissection.

Becker (1981) synonymized A. vestalis
Antaeotricha floridella is described as a new species because no other white species with similar genitalia were described by Meyrick (Clarke 1955), Walsingham (1909Walsingham ( -1915, Walker (1864), Zeller (1854Zeller ( , 1855Zeller ( , 1873Zeller ( , 1877 or other authors. The West Indian Antaeotricha fauna is depauperate, with only three species (Duckworth 1969). Descriptions and illustrations of all species currently placed in Antaeotricha were examined, a task greatly facilitated by the illustration of Meyrick's numerous species by Clarke (1955) and by the concentration of other descriptions among a few authors (e.g. Walker 1864; Walsingham 1909Walsingham -1915Busck 1911Busck , 1920Zeller 1854Zeller , 1877see Becker 1984 for complete list). Almost all species are described as having some forewing maculation, and those without are some shade of brown.
The new species keys to couplet 8 in Barnes and Busck (1920: 238), requiring a new line, "forewings pure white without discal spots." In the key of Duckworth (1964: 27), males run to couplet 13 (A. unipunctella or A. vestalis), and females run to A. osseella or A. unipunctella. New keys are provided below that include A. floridella and another species described after 1964. Duckworth's (1964) key is inaccurate as it pertains to the small, unicolorous species. In couplet 12 of the key, the "[g]nathos divided into two lobes at tip" could apply equally to A. osseella and A. decorosella (Busck, 1908 a) as well as to A. unipunctella and A. albulella; he correctly noted the "notched" condition of the gnathos in the species accounts. In couplet 14, the low subapical spine or tooth of the phallus (Fig. 11: s t) is stated to be present in A. osseella and absent in A. decorosella. In our dissections, the spine in A. osseella varies from sharply angulate to a low hump to entirely absent. In a specimen that appears to represent A. decorosella (MGCL slide 2166), a low rise is present. This specimen has many robust chaetae on the apical two thirds of the anellar lobe, which is diagnostic for male A. decorosella. Furthermore, the variation of the spine is as follows: A. unipunctella, absent or a low serrate ridge; A. albulella, a very low expansion but not an angulate tooth; A. floridella, present or absent. This variable character should be avoided for separating species.
Antaeotricha albulella, A. osseella, and A. floridella adults are active at the same time and location. John B. Heppner has caught all three species at the Welaka Forest Conservation Station, 28-31 July 1986. A male specimen each of A. albulella and A. floridella were collected at Pellicer Creek (Flagler Co.) on 10 April 1954 (CMNH). The road numbers in Ocala National Forest changed in 2008: Forest Road 88 is now 11, and 97 is now 09.
Antaeotricha floridella is known to feed on two species of oak: Quercus geminata and possibly Q. minima. The latter species may be misidentified, since it resembles juvenile or rhizomatous forms of other oaks (Nixon 1993). Host plants of A. albulella, recorded from pinned specimens donated to the FSCA by D.H. Habeck, include Quercus laevis Walter (turkey oak), Q. nigra L. (water oak) (with feeding habits "galls" and "leaf tier"), Q. incana W. Bartram (bluejack oak), Q. myrtifolia Willd. (myrtle oak), Q. inopina Ashe (scrub oak), and Q. chapmanii Sarg. (Chapman's oak). The plant voucher specimens could not be located, so their identifications could not be verified.
Two plant communities in Ocala National Forest in Marion and Putnam counties, the sandhill and sand pine communities, have been collected extensively by TSD over the past several years using both mercury vapor light and ultraviolet light. Antaeotricha floridella occurs in both plant communities, as well as in strict scrub habitat with minimal canopy not surveyed by TSD. In the sandhill community, the common species of pine is Pinus palustris Miller (longleaf pine), and the common species of oak is Q. laevis. The leaves of turkey oak are deciduous, mostly falling in September and October, with a few leaves remaining on the trees during the winter. New foliage begins to appear in March and April. In the sand pine community, the predominant pine is Pinus clausa Chapman ex Engelmann (sand pine), and the common oak is Q. myrtifolia. In Ocala National Forest, myrtle oak tends to be a thicket-forming shrub. Leaves are "tardily deciduous," meaning that a few leaves fall during the winter months, but the majority of leaf fall occurs during late February and March, just as the trees begin to flower and new leaves develop. Quercus geminata is also tardily deciduous (Godfrey 1988). The type locality of A. floridella has Q. geminata, Q. laevis, and Q. hemisphaerica in abundance, and Q. myrtifolia and Q. nigra in small numbers.
Extensive collecting in a large mesic forest near Anthony (Marion County, Florida) by TSD with mercury vapor and ultraviolet lights and sugar bait has failed to produce any specimens of A. floridella. This forest has large numbers of three species of oaks: Quercus virginiana Miller (live oak), Q. hemisphaerica Bartr. ex Willd. (laurel oak), and Q. nigra (water oak). The leaves of all of these species are tardily deciduous with primary leaf fall occurring in late February and March just prior to flowering and new leaf growth.
With minimal host information, it is open to question whether A. floridella is monophagous on Quercus geminata, oligophagous on oaks with overwintering foliage, or has more hosts. Sand live oak occurs in both plant communities and others in Florida. It occurs on the southeastern coastal plain from Virginia to Mississippi (Godfrey 1988), so the plant's distribution cannot explain the moth's restriction to peninsular Florida. On the other hand, a broader host range would predict occurrence in non-xeric habitats. The phenology of the immature stages is unknown, in particular of the overwintering stages. It is not obvious that A. floridella has adaptations to abiotic characteristics of xeric habitats, so affinity for some host is assumed.
A partly historical explanation for the peninsular distribution may be isolated evolution in habitat islands of sandhill and scrub (Webb 1990). Few Lepidoptera are known to be restricted to those habitats and also endemic to Florida. One moth species is known to be endemic to Florida rosemary scrub, a geometrid that feeds on Ceratiola ericoides Michx. (Deyrup 1989). Kons and Borth (2006) list 51 species of Lepidoptera that, based on preliminary evidence, may be dependent on the first kind of plant community (turkey oak-longleaf pine sandhills), but the majority of these also occur in similar habitats outside peninsular Florida. Comparable data are lacking for sand pine communities. Although most specimens of A. floridella were collected in longleaf pine sandhills or sand pine scrub, the specimens from Jonathan Dickinson State Park and Archbold Biological Station may have been collected in other kinds of scrub habitat (Myers 1990). It has not been found in collections (MEM, FSCA) from the ecologically similar Ohoopee Dunes in Georgia, although A. albulella occurs there. Kons and Borth (2006) discuss in depth the methods and caveats of associating species with xeric habitats based mainly on adult specimens, and they emphasize the need to test hypotheses of habitat dependence with further collection data.
The Antaeotricha albulella group (including A. osseella, A. unipunctella, and A. decorosella) is probably a recent radiation, with A. floridella as a peninsular vicariant. It is not simply a peripheral isolate of A. albulella, because it lacks the autapomorphies of the latter species (the broad gnathos and prominent SVIII pads). Preliminary genetic data corroborates the species' distinct status. A specimen of A. floridella in the CNC, dissected by J.-F. Landry, has a slightly greater percentage distance than intraspecific clusters of A. albulella based on mtCO1 (J.-F. Landry, pers. comm. 2014). The sequence data are available at: http://www.boldsystems.org/index.php/Public_RecordV iew?processid=MNAB391-07. Study of more genetic data should be useful to clarify the A. albulella group. All species and populations should be sampled and the data analyzed with character-based phylogenetic methods to discover diagnostic apomorphies. Collection of Antaeotricha specimens across known phylogeographic discontinuities in North Central Florida and the Panhandle could demarcate the northern limit of the distribution of A. floridella (Soltis et al. 2006).
Additional species examined. Dissected specimens of several other species were examined to construct the keys, except Gonioterma crambitella (Walsingham, 1889), figured in Duckworth (1964). Unless otherwise indicated, dissection slides are assigned MGCL slide numbers and deposited in FSCA.

Keys to species
The following keys apply only to taxa with white or pale-colored wings (yellowish, pale orange, or beige) that are effectively concolorous. Species of Antaeotricha that have a dark shade on the the forewing posterior margin are excluded. Other stenomatines (Gonioterma Walsingham) and Oecophoridae that have similarly concolorous wings are included.