Aspilanta, Nieukerken & Eiseman, 2020

Nieukerken, Erik J. van & Eiseman, Charles S., 2020, Splitting the leafmining shield-bearer moth genus Antispila Huebner (Lepidoptera, Heliozelidae): North American species with reduced venation placed in Aspilanta new genus, with a review of heliozelid morphology, ZooKeys 957, pp. 105-161 : 105

Genus Aspilanta gen. n.

Antispila : auct. partim, nec Hübner, 1825.

Antispila ampelopsifoliella group; van Nieukerken et al. 2012: 66.

Antispila "group II"; Milla et al. 2019: 133.

Type species.

Antispila oinophylla van Nieukerken & Wagner, 2012: 38, by present designation.

Differential diagnosis.

Very small moths, wingspan between 4.0 and 6.2 mm, with a forewing pattern of metallic-silvery markings, comprising an oblique fascia at ¼, a postmedial pair of spots (one costal and one dorsal), and usually a small apical spot (only absent in A. viticordifoliella ); fringe line more or less distinct. Males never with androconial scales or hair-pencils. Antennae with only 16-20 segments. Antispila species in North America never have an apical spot. Aspilanta species are diagnosed by the reduced venation (Figs 9 - 13 ); in Antispila the discoidal cell is present and more veins are retained (illustrated in van Nieukerken et al. 2012; van Nieukerken et al. 2018); most Antispila species are larger and have more antennal segments. Separated from Heliozela species by more extensive colour pattern and apical spot, and Heliozela species have the venation with discoidal cell and a distinct epiphysis on foreleg. Coptodisca species are readily recognised by their colour pattern ( Bernardo et al. 2015; Eiseman 2019). The genera Holocacista and Antispilina , not yet known from the New World, have a very similar venation, but always lack the apical spot. Moreover, Holocacista species have a small epiphysis on the foreleg, and the phallus bears an unusually long, often recurved appendix.

Description.

Adults (Figs 1-8 , 45-50 ). Very small moths, forewing length ca. 1.8-2.8 mm (wingspan ca. 4.0-6.2 mm), no sexual dimorphism.

Head (Figs 14-18 ). Almost oval in outline. Eyes in latero-ventral position, ventral margin not reaching lower margin of head. No sutures present. Anterior tentorial arms very slender, prominently curved laterally before converging towards frons. Vestiture comprising lamellar scales, closely appressed on head, in dry specimens scales on vertex sometimes raised, probably an artefact as a result of drying. Mouthparts: labrum narrow, pilifers absent. Mandibles small, as long as broad, relatively well sclerotised (Fig. 16 ). Maxilla with galea well developed and almost twice as long as head; maxillary palp reduced to a single segment. Labial palp well developed, 3-segmented, drooping, slightly shorter than head capsule; distal segment almost 3 × as long as second segment; depression for Organ von Rath not seen. Antenna (Figs 14 , 18 ) ca. half length of forewing with 14-18 flagellomeres (16-20 segments) [best counted in denuded specimens on slides], no sexual dimorphism. Scape and pedicel of equal length, slightly shorter and wider than flagellomeres. Flagellomeres (Fig. 18 ) cylindrical, ca. twice as long as wide, each with two annuli of scales, most dark, some apical flagellomeres may be white. Pecten present, but not easily visible; with ca. 4-5 hairs.

Thorax. Vestiture of appressed lamellar scales, either concolourous with ground colour of forewings or more metallic and similar to vestiture of head. Foreleg (Fig. 20 ) without epiphysis.

Wings. Male retinaculum a series of 7-12 hook-shaped bristles (Fig. 19 ), arising from a thickened serrate portion of Sc. Frenulum in male a strong curved bristle (Figs 12 , 13 ), in female two bristles present (Fig. 10 ); pseudofrenular bristles in male absent. Humeral field with scattered microtrichia, otherwise microtrichia restricted on wing membrane to area just posterior to retinaculum, arranged in longitudinal rows. Scale sockets regularly spaced, not in distinct rows.

Venation (Figs 9 - 13 ). Forewing with Sc to middle of costa. R unbranched, a separate vein, to costa, but a persistent trachea connecting R with Rs+M+CuA. Rs+M+CuA ending in 3-4 branches, interpreted as Rs1+2 to costa, Rs3+4 to termen, M and CuA to dorsum. Hindwing with Sc+R to costa, Rs+ M with 2-3 branches, Rs to costa, 1 or 2 branches of M to termen and dorsum; CuA a separate vein to dorsum.

Wing pattern (Figs 1-8 ). On forewing typically comprising a silvery white metallic fascia at 1/3, widest at dorsum, and a similarly coloured pair of opposite spots at 2/3 on a dark background, brown to black, with a small silvery blue spot in apex, equidistant to dorsum, costa and fringe line, but the apical spot is absent in A. viticordifoliella . A fringe line often present, with fringe scales pale. Hindwing uniform grey. Androconial scales absent in all species examined.

Pregenital abdomen. Abdominal sclerites weakly sclerotised. Anterior sternum II subtriangular, free.

Male genitalia (Figs 21-28 ). Vinculum (SIX) very long, anteriorly often reaching beyond anterior margin of segment VI, almost cylindrical; approximately 2/3 of total length of genitalia. Tegumen (TIX) narrow, often bilobed, or medially indented, or truncate; probably a composite structure with uncus. Gnathos absent. Valva approximately triangular, with stalked pectinifer halfway to inner margin, pecten comprising 10-22 blunt sensilla (comb teeth); transtilla typically with medial anterior projection, sublateral processes long. Phallocrypt (manica) with some to many strongly sclerotised conical spines, often arranged in an asymmetric fashion, or with many smaller spines. Phallus outer tube often with remarkable appendices of different sizes and shapes. Juxta present, often bilobed or arrow shaped, in hydrangaeella with extra spines laterally.

Female genitalia (Figs 29-33 ). SVIII truncate, TVIII deeply indented. Oviscapt with few lateral cusps. Anterior and posterior apophyses subequal in length, a short interapodemal process between anterior apophyses (Fig. 29 ). Spermathecal papilla usually with circular sclerotisation. Ductus spermathecae with several coils.

Larva (Figs 34-42 ). Yellow or whitish, usually with brown to almost black head capsule and prothoracic sclerites and dark anal plates; no plates present on other segments, but concentration of cuticular swellings can give impression of darker plates on abdomen in some species. Head prognathous, 2 stemmata at either side. Thorax with elongate dorsal and ventral sclerites without adornment; 10th (last) abdominal segment with single dorsal and paired ventral sclerites, with several prominent setae; other thoracic and abdominal segments covered with small transverse swellings. Legs and prolegs absent but paired ambulatory calli on T2 and T3 (ventral and dorsal) and fused ventro-medial calli on A3-6. Number of instars unknown, but likely with four feeding instars and a fifth non-feeding instar that constructs the case in which it pupates, in analogy to Holocacista , Coptodisca , Antispila and Heliozela ( Dziurzyński 1948, 1952; Marchi 1956; Prota 1962; Maier 1988).

Biology.

Host plants. Most species feed on Vitaceae , one each on Hydrangeaceae and Myricaceae .

Life history.

Eggs are inserted in leaf tissue, often near a vein or leaf margin. All species construct leafmines, either starting as a narrow linear mine and later widening into a blotch, or sometimes starting almost immediately as a blotch mine. All frass is deposited in the mine, initially filling or irregularly scattered in the linear portion, later often scattered in the blotch or pushed by the larva to one side. During the penultimate (fourth) instar an oval section is cut out from both epidermal layers, forming a portable case or “shield”. This shield (Figs 55 , 68 , 76 , 93 , 106 ), later forming the cocoon, is more or less flat, without the raised central ridge that is characteristic for Antispila . The larva descends with its shield on a strand of silk and may wander for some distance before finally attaching the shield at one end to a substrate (leaf, trunk, leaf litter, etc.), where it moults to the fifth non-feeding instar and later pupates. The pupa protrudes from the opposite end of the shield when the adult emerges. As far as we know, most species are bivoltine, overwintering as fifth instar larva in the cocoon, but A. voraginella and possibly A. ampelopsifoliella are univoltine. Adults are usually day flying and can be swept from the hosts, but rarely come to light. Several specimens were taken in Malaise traps (DNA barcoded material) and in several cases provide the only accurate phenology data for adults.

Distribution.

North America; DNA barcodes suggest a rich fauna in Central America: Mexico, Honduras, Costa Rica, likely also elsewhere in the Neotropics (see under Composition).

Etymology.

The name Aspilanta is an anagram of Antispila , where one “i” was replaced by an “a”. The gender of the name is to be regarded as feminine.

Composition.

In the checklist below we provide the original genus in brackets, type locality, and the hostplant of the types. The species are listed according to the position in the recent phylogenetic analyses ( Milla et al. 2017, 2019).

We also include the candidate species Aspilanta “Vitis1_USA” (van Nieukerken et al. 2012) and A. “Vitis.arizonica_USA”. Some publicly available DNA barcodes (Fig. 44 ) closely match confirmed Aspilanta sequences, suggesting further candidate species and a rich fauna in Mexico, Honduras and Costa Rica, but until these taxa are examined morphologically, we omit them. The following BINs are concerned: Mexico: BOLD:ACZ5051, BOLD:ACP0240, BOLD:ACO9420, BOLD:ACU0821, BOLD:ACT4781; Costa Rica: BOLD:ADA1988, BOLD:ACL9188; Honduras: BOLD:ACF9350.

The Neotropic species Antispila trypherantis Meyrick, 1916 (Guyana), A. pentalitha Meyrick, 1916 (Guyana) and A. cyclosema Meyrick, 1921 (Brazil) may also belong in Aspilanta , based on their original descriptions that cite the presence of an apical dot, but without examination of types, we refrain from recombination here. Also the Patagonian group of species, associated with Nothofagus ( Nothofagaceae ), for which Nielsen in his unpublished thesis proposed the name " Neospila ", could belong in Aspilanta on the basis of the very similar externals (Fig. 7 ), although following the latest phylogeny, where it occurs as Genus14, its inclusion would make Aspilanta paraphyletic ( Milla et al. 2019) (Fig. 43 ).

In the Museum of Comparative Zoology (Cambridge, MA), there is a series of externally similar moths of unknown provenance, ex coll. Dietz, allegedly reared from poison ivy, ( Toxicodendron radicans , Anacardiaceae ) with the manuscript name " Antispila rhoifoliella " (handwritten label: on Rhus radicans . Coll 9.7.[18]99, many mines empty, larva pale, green frass line; head + 1 dark brown. [word crossed out] mine begins with a fine tract along edge of leaf, expands & frass collects along edge of mine.). These specimens have emergence dates of 1-20 June 1900 (written as “19C”). As we have never seen such mines on poison ivy we cannot exclude the possibility that Virginia creeper was mistaken for poison ivy, as both often grow together; in this case the series would likely represent Aspilanta ampelopsifoliella . We thus ignore this information until these specimens have been examined in more detail.

Figures

Figure 43. Phylogeny of the cosmopolitan leafmining clade of Heliozelidae, part of fig. 1 in Milla et al. (2019) (Maximum likelihood phylogeny generated using iq-tree, topology from filtered _ nt 123 analysis). ' Antispila ' Group II replaced by Aspilanta, branch supports removed and numbers of possible apomorphies added; see text.

Figure 44. Neighbor-Joining tree of COI barcodes of Aspilanta species, including Nearest Neighbours. Several species of Coptodisca serve as outgroup. Data with country, and for Canada and United States also the abbreviation for Province or State, plus the BIN number.

Figures 9 - 11. Aspilanta species, denuded wings, showing venation. 9 A. oinophylla, male, veins labelled, RMNH. INS. 24257 10 A. hydrangaeella, female, RMNH. INS. 25191 11 A. ampelopsifoliella, male, RMNH. INS. 24376. Scale bars: 500 μm.

Figures 12 - 13. Aspilanta species, denuded wings, showing venation. 12 A. voraginella, male, RMNH. INS. 23917 13 A. argentifera, male, RMNH. INS. 23917. Scale bars: 500 μm.

Figures 1 - 8. Aspilanta species, mounted adult moths. 1 A. oinophylla, male, USA, VT, RMNH. INS. 24378 2 A. hydrangaeella, female, USA, NC, RMNH. INS. 25191 3 A. ampelopsifoliella, male, USA, CT, RMNH. INS. 24377 4 A argentifera, female, USA, MA, RMNH. INS. 25019 5 A. voraginella, male, USA, AZ, RMNH. INS. 23918 6 A. argentifera, female holotype 7 Undescribed species in unnamed genus 14 (" Neospila "), male, Chile, Osorno, 20 km W of Entre Lagos, 17. x. 1981, leg. Nielsen & Karsholt, genitalia slide EJvN 4632, ZMUC 8 A. viticordifoliella, female, Canada, Ottawa, from Parthenocissus, CNCLEP 00122404. Scale bars: 1 mm.

Figures 45 - 50. Aspilanta species, live adult moths. 45 A. oinophylla, male, Italy, Suedtirol, Eisacktal, Klausen, 650 m, e. l. 1. viii. 2019, photograph Dieter Robrecht 46 A. hydrangaeella, female, dorsal view, NC, photograph EJvN 47 A. ampelopsifoliella, female, Pelham MA, photograph CSE 48 A. ampelopsifoliella, male, dorsal view, VT, photograph EJvN 49 A. argentifera, female, Stockbridge MA, photograph CSE 50 A. viticordifoliella, female, Pelham MA, photograph CSE.

Figures 14 - 20. Aspilanta oinophylla, adult (male) morphology, RMNH. INS. 24440. 14, 15 Head, anterior and posterior views 16, 17 Detail of mouthparts, anterior and posterior views; m = mandible 18 Detail of flagellomeres, middle part of antenna, showing scale sockets of two scale rings per flagellomere 19 Forewing, underside, detail of retinaculum 20 Prothorax with forelegs. Scale bars: 100 μm, 200 μm (20).

Figures 21 - 28. Aspilanta species, male genitalia. 21 A. oinophylla, phallus separate, RMNH. INS. 23920 22 A. ampelopsifoliella, phallus in situ, RMNH. INS. 24376 23 A. hydrangaeella, phallus in situ, RMNH. INS. 25192 24 A. voraginella, phallus separate, holotype, slide EJvN 3916 25 ditto, detail of transtilla 26 A. oinophylla, detail valva (flattened), RMNH. INS. 15247 27, 28 A. hydrangaeella, RMNH. INS. 25190, details of resp. tegumen and valvae. Scale bars: 100 μm.

Figures 29 - 33. Aspilanta species, female genitalia. 29 A. argentifera, RMNH. INS. 25019 30 A. oinophylla, RMNH. INS. 24211. 31 - 33 Tip of oviscapt: 31 A. argentifera, RMNH. INS. 25019 32 A. oinophylla, RMNH. INS. 24211 33 A. ampelopsifoliella, RMNH. INS. 15220. Scale bars: 200 μm (29, 30); 50 μm (31 - 33).

Figures 34 - 42. Aspilanta species, larval morphology, final feeding instar (4 th) and non-feeding instar (5 th, 36). 34 A. ampelopsifoliella, ventral aspect, ethanol preserved larva, RMNH. INS. 18672 P 35 A. viticordifoliella, ventral aspect, ethanol preserved larva, RMNH. INS. 18509 P 36 A. argentifera, head capsule, RMNH. INS. 18566 P 37 - 39 A. ampelopsifoliella, head and thorax, resp. focussed at mid levels (head only), dorsally and ventrally, RMNH. INS. 18672 P 40 A. oinophylla, head and thorax, RMNH. INS. 18394 P 41 A. ampelopsifoliella, last 3 abdominal segments, dorsal aspect, RMNH. INS. 18672 P 42 A. oinophylla, last 3 abdominal segments, ventral aspect, RMNH. INS. 18394 P. Scale bars: 1 mm (34, 35), 100 μm (36, 37, 41, 42), 200 μm (38 - 40).

Figures 51 - 58. Aspilanta oinophylla, leafmines, larvae and shields. 51, 52 GA, Chattahoochee NF, 14. x. 2010, type locality, Vitis aestivalis, EvN 2010266 53, 56 MA, Northfield, 13. ix. 2016, V. riparia, CSE 54, 58 TN, Great Smoky Mts NP, 2. x. 2010, V. vulpina, EvN 2010119 55, 57 VT, Button Bay SP, 16. ix. 2011, V. riparia, EvN 2011253.

Figures 59 - 68. Aspilanta hydrangaeella, leafmines, larvae and shields, on Hydrangea arborescens. 59, 60, 64 GA, Chattahoochee NF, 14. x. 2010, EvN 2010279 61, 63, 68 OH, South Bloomingville, 13. ix. 2012, CSE, (61 = RMNH. INS. 29601) 62 OH, Crane Hollow, 5. viii. 2016, CSE 65 - 67 NC, Great Smoky Mts NP, 28. ix. 2010, EvN 2010073.

Figures 69 - 79. Aspilanta ampelopsifoliella, leafmines, larvae and shields, on Parthenocissus quinquefolia. 69, 74 VT, Williston, 28. viii. 2016, CSE 3764 (same mine) 70, 76 - 78 MA, Pelham, 30. viii, 4. ix. 2013, CSE 1102, 1108 71 MA, Nantucket, Squam Swamp, 7. ix. 2011, CSE-C 4 72 MA, Northfield, 16. ix. 2016, CSE 73 MA, Nantucket, Stump Pond, 5. ix. 2019, CSE 75 VT, Button Bay SP, 16. ix. 2011, EvN 2011254 79 MA, Bridgewater, 16. viii. 2013, CSE 983.

Figures 88 - 96. Aspilanta argentifera, leafmines, larvae and shields. 88 NC, Laurinburg, 27. ix. 2016, Morella cerifera, CSE 89 MA, Northfield, 26. x. 2015, Comptonia peregrina, CSE 90 VT, Chickering Bog, 6. ix. 2015, Myrica gale, EvN 2015222, showing wilted leaf tip 91, 96 MA, Erving, 27. x. 2014, Comptonia peregrina, CSE 1557 92, 93 MA, Nantucket, Radar Hill, 15. xi. 2015, Morella caroliniensis, CSE 2398, same mine at different stages 94 MA, Stockbridge, 16. vii. 2017, Myrica gale CSE 4096, showing very long linear portion directly along midrib 95 MA, Nantucket, UMass field station, 5. xi. 2017, Morella caroliniensis, CSE 4546.

Figures 97 - 106. Aspilanta viticordifoliella, leafmines, larvae and shields on Parthenocissus quinquefolia and P. vitacea (104). 97, 99, 100, 105, 106 MA, Northampton, 13. ix. 2013, CSE, 105 shows the left mine of 100, 106 showing flat shield to distinguish it from Antispila species 98 VT, Williston, 28. viii. 2016, CSE 101 MA, Great Barrington, 16. ix. 2017, CSE 102, 103 VT, Button Bay SP, 16. ix. 2011, EvN 2011254 - 2 104 QC, Aylmer, 23. viii. 2015, EvN 2015160.