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Hawaiian Philodoria (Lepidoptera, Gracillariidae, Ornixolinae) leaf mining moths on Myrsine (Primulaceae): two new species and biological data
expand article infoShigeki Kobayashi§, Chris A. Johns|, Carlos Lopez-Vaamonde#, Camiel Doorenweerd¤«, Atsushi Kawakita», Issei Ohshima˄, David C. Lees˅, Sofia Hanabergh, Akito Y. Kawahara
‡ University of Florida, Gainesville, United States of America
§ Osaka Prefecture University, Osaka, Japan
| Florida Museum of Natural History, Gainesville, United States of America
¶ INRA, UR0633 Zoologie Forestière, Orléans, France
# Université de Tours, Tours, France
¤ University of Hawaii, Honolulu, United States of America
« Naturalis Biodiversity Center, Leiden, Netherlands
» Kyoto University, Shiga, Japan
˄ Kyoto Prefectural University, Kyoto, Japan
˅ Natural History Museum, South Kensington, United Kingdom
Open Access

Abstract

This paper provides new taxonomic and biological data on a complex of gracillariid moths in the endemic genus Philodoria Walsingham, 1907 that are associated with Myrsine (Primulaceae) in the Hawaiian Islands, United States. Two new species, Philodoria kauaulaensis Kobayashi, Johns & Kawahara, sp. n. (host: Myrsine lanaiensis, M. lessertiana, and M. sandwicensis) and P. kolea Kobayashi, Johns & Kawahara, sp. n. (host: M. lessertiana) are described. Biological data are provided for two previously described species that also feed on Myrsine: P. auromagnifica Walsingham, 1907 and P. succedanea Walsingham, 1907. For the first time we detail and illustrate genital structures, immature stages, biology, and host plants of P. auromagnifica and P. succedanea. Philodoria kolea, P. auromagnifica, and P. succedanea occur in sympatry on the island of Hawaii (Big Island), but each species differs in behavioral characters: P. kolea utilizes leaves of seedlings and forms a serpentine mine, whereas the latter two utilize leaves of larger plants, and form linear or serpentine to blotch mines. More broadly, leaf mine forms and diagnostic characteristics of the Myrsine-feeding species complex of Philodoria (as currently known) are reviewed and illustrated.

Keywords

DNA barcoding, leaf mine form, Myrsine knudsenii, Myrsine wawraea, taxonomy

Introduction

Hawaii constitutes one of the most geographically isolated archipelagos and harbors thousands of unusual, highly threatened endemic species. Phytophagous insects that rely on endemic Hawaiian plants are of special risk as they depend on the survival of their native host plants. The Hawaiian Islands measure just 0.02% of the area of the United States, but account for nearly 70% of the United States’ historically documented plant and animal extinctions (Wagner et al. 1999). In all, over 360 Hawaiian animal and plant taxa are currently listed as either threatened or endangered under the federal and state Endangered Species Acts. More than 38% of native Hawaiian plants are threatened and 94% of Hawaiian insects are endemic (Evenhuis and Eldredge 1999). Leaf miners have achieved extraordinary localized diversity and are a major component of island ecosystems throughout the Pacific.

Philodoria Walsingham, 1907 is a genus of endemic Hawaiian leaf-mining micromoths, containing approximately 30 species, for which the classification remains largely in disarray. The genus can be distinguished from other genera in the Gracillariidae subfamily Ornixolinae by a hindwing with small frenular bristles along the costa in both sexes (Zimmerman 1978, figs 432–435); by a dorsal flap extending from the posterior margin of tergum VIII in the male; and by the female lamella antevaginalis that is sclerotized and semicircular in shape. Many Philodoria host plants are threatened along with their native habitat. Indeed, herbarium samples provide one of the few documented cases globally of a probable moth extinction, albeit an undescribed species (Johns et al. 2014). The genus was first described with seven species by Walsingham (1907), and the type species was designated as P. succedanea Walsingham, 1907. Zimmerman (1978) published a monograph of Hawaiian insects following Walsingham’s work and many papers by Swezey (19101946). Zimmerman divided Philodoria into two subgenera, P. (Eophilodoria) and P. (Philodoria), based on the size of the maxillary palpus. His classification was recently rejected by Johns et al. (2016), who constructed a preliminary molecular phylogeny of Philodoria based on three genes for 11 Philodoria species. In their analyses, the two Philodoria subgenera were not monophyletic and morphological characters used to classify them were inferred as homoplasious; the subgenus Eophilodoria Zimmerman, 1978 was established as a subjective junior synonym of the genus Philodoria Walsingham, 1907. In addition, Johns et al. (2016) provided new host plant and distribution data for these 11 species. While Philodoria was historically treated as similar to Elachista (Elachistidae, Gelechioidea), it unequivocally belongs in Gracillariidae (Kawahara et al. 2017) and the genus is unrelated to Gelechioidea (Breinholt et al. 2018). Based on taxon sampling of exemplar gracillariid genera, Philodoria appears to be phylogenetically closely related to the ornixoline genus Chileoptilia Vargas & Landry, 2005 from Chile (Kawahara et al. 2017).

Larval host plants of Philodoria are diverse, with up to six plant orders (Asterales, Apiales, Ericales, Malvales, Myrtales and Rosales) reported as hosts, among which Asterales (Asteraceae: Dubautia) and Rosales (Urticaceae: Pipturus) appear as dominant hosts (Swezey 1954; Zimmerman 1978). Another host plant that is used by multiple Philodoria species is Myrsine (Ericales: Primulaceae). According to Zimmerman (1978) and label data from Philodoria specimens in the collection of the Bernice Pauahi Bishop Museum (BPBM), there appear to be numerous undescribed Philodoria species on Myrsine. In total, 19 Myrsine species are known to be endemic to the Hawaiian Islands (Wagner et al. 1999), and two species of Philodoria that feed on Myrsine have been described: P. succedanea Walsingham, 1907 (type species of the genus) and P. auromagnifica Walsingham, 1907, both with similar scale colors and genital characters (Walsingham 1907, Zimmerman 1978).

In late April 2016, several of the authors collected numerous blotch mines on leaves of Myrsine species at two sites on the island of Hawaii (Big Island). Initially, we believed that these mines were created by a single Philodoria species, but after studying them, we realized that they comprised diverse larval habits (e.g., forms with spiral or linear mines, larvae in fallen or in situ leaves, and some adults which emerged with relatively black forewings). Recent studies (Kawahara et al. 2009, Davis and Wagner 2011, Davis and De Prins 2011, Brito et al. 2013, Moreira et al. 2017) have shown that important diagnostic characters of gracillariids are present in larvae and pupae. However, insufficient early stages have been preserved until now for diagnostics and identification. In this paper, we describe two new species, Philodoria kauaulaensis (hosts: Myrsine lanaiensis, M. lessertiana, and M. sandwicensis) and P. kolea (host: M. lessertiana), and also the genitalic structures, immature stages and new host plant information for the two previously described Myrsine-feeding species, P. succedanea and P. auromagnifica. Four species were reared, and their mine forms and characters are here reviewed and illustrated.

Materials and methods

Taxon sampling

All adult moths were reared from leaf mining larvae and their pupal cocoons. Leaf mines and cocoons were collected between 2013–2016 in the locations listed in Table 1. Among the material examined, the final dates refer to the adult emergence and ‘em.’ signifies that an adult emerged and was mounted as a dry pinned specimen; ‘stored’ signifies a dead adult that was stored in 99 % ethanol or RNAlater solution (Thermo Fisher Scientific). Type material designated by Lord Walsingham and specimens collected by Dr K. & Mrs. E. Sattler in the Natural History Museum (NHMUK), and those collected by Mr. O. H. Swezey at the BPBM and the National Museum of Natural History, Smithsonian Institution (USNM) were also examined. Immatures in leaves were reared in plastic cups (420 ml: 129 mm in diameter at top and 60 mm in depth) containing wet cotton at 20 ± 5 °C under a photoperiod condition in the laboratory of 13–16L (hours light) 8–12D (hours darkness).

Study sites of Philodoria species and host plants.

No. Locality Island Collection Longitude and latitude Elevation (m) Study Specimens ID Species name Host plant
1 Limahuli, Upper Preserve Kauai 22.1858°N, 158.58°W 900 AYK-HI10-001, 002 Philodoria sp. nr. splendida Unknown
2 Kokee Kauai 22.1508°N, 159.6370°W 1230 CJ-433, 442 P. succedanea Myrsine knudsenii
3 Kahili Kauai No data 400–500 CJ-148 P. auromagnifica M. wawraea
4 Mt. Kaala Oahu 21.4161°N, 158.0997°W 800 CJ-526 P. succedanea M. lessertiana
5 Kamakou Molokai 21.1184°N, 156.9049°W 1170 CJ-241 P. auromagnifica M. lessertiana
6 Eke Maui 20.9379°N, 156.5801°W 870 CJ-136, 531 P. succedanea M. lessertiana
7 Kauaula* Maui 20.8738°N, 156.6183°W 900 CJ-381 P. kauaulaensis M. lanaiensis
8 Waikamoi Maui 20.7826°N, 156.2304°W 1800 CJ-539 P. succedanea M. lessertiana
9 Upper Hamakua Ditch Trail Hawaii 20.0511°N, 155.238°W 900 CLV6239 Philodoria sp. nr. floscula Pipturus sp.
10 Kohala Watershed Partnership Hawaii No data 700–1500 CJ-419 P. succedanea M. sandwicensis
11 Kaumana Trail Hawaii 19.45°N, 155.21–155.19°W 900–1000 HILO016 P. kolea Myrsine sp.
12 Hawai’i Volcanoes National Park† Hawaii 9.4138°N, 155.238°W 1090 SKH-5, 10, 13, 15; P. succedanea, P. auromagnifica M. lessertiana;
HILO053, 054, 059; P. kolea; Metrosideros polymorpha
AYK0001, 0002, CLV6240 P. basalis

Morphology and nomenclature

Descriptions focused on the adult stage and leaf mines because of limitations of other material, and because these stages provide a wealth of morphological traits useful for diagnosis. Photographs of leaf mines were taken primarily in the field using Canon EOS 60D and 5D MKIII digital cameras. Some leafmines were scanned using an EPSON Perfection V600 Photo scanner. Observations and measurements were made under a Leica M2 16 dissection microscope at 71–115× and a Leica S6E microscope at 6.3–40× with the aid of a micrometer scale. Images of adults were captured using a Olympus E-330 camera and Moticam 580 5.0 MP. Images were taken at various depths and subsequently stacked using the Helicon Focus 6.22. All images were then edited with Adobe Photoshop Elements 9 into final figures.

For genitalic dissections, the whole abdomen was removed and boiled for 3–4 min in 10% aqueous KOH, and residual scales and soft parts were removed in 70% ethanol. Genitalia were then stained in Chlorazol Black E (1% solution in 70 % ethanol) or acetocarmine for 0.5–1h, dehydrated in a series of 70−100 % ethanol and mounted in Canada balsam on a glass slide.

Type material and additional specimens used in the present study are preserved in the collections of the BPBM, the McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History (FLMNH) and Naturalis Biodiversity Center (RMNH). Terms used for describing wing color pattern are summarized in Fig. 1, and forewing characters follow the terminology of Walsingham (1907) and Zimmerman (1978). Terms for genitalia essentially, follow Zimmerman (1978) and “gnathos” is employed to indicate the sclerotized V-shaped transverse band joining the ventral base of tegumen. Scientific names of plants follow the Plant List (www.theplantlist.org).

Figure 1. 

Nomenclature adopted in this study for the characterization of forewing pattern in Myrsine-feeding Philodoria. Abbreviations: as: apical spot; bb1–bb3: bronze color band; bp: basal patch; bl: basal line; cs: costal spot; tf: transverse fascia; tp: transverse patch; w1– w5: white color band.

DNA sequencing and analysis

A total of 16 specimens were DNA barcoded. DNA extraction, PCR amplification and sequencing of the 658 base pair Cytochrome Oxidase 1 (COI) “barcode” region for two specimens were carried out at the Canadian Centre for DNA Barcoding (CCDB, Biodiversity Institute of Ontario, University of Guelph) following a published protocol (deWaard et al. 2008). Five specimens were extracted at the Florida Museum of Natural History, McGuire Centre for Lepidoptera and Biodiversity at the University of Florida, Gainesville, FL, USA, using the OmniPrep extraction kit and sequenced at University of Florida’s Interdisciplinary Center for Biotechnology Research (ICBR), one specimen was extracted at the Department of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Kyoto, Japan (KPU) using the DNeasy Blood & Tissue Kit (Qiagen, Inc., Valencia, California), and single-stranded PCR and sequencing for this specimen was carried out at the Operon Sequencing Center following the manufacturer’s protocol (Eurofins, Tokyo, Japan). Eight specimens that were sequenced at Naturalis Biodiversity Center were extracted using a Macherey-Nagel magnetic bead DNA extraction kit on a KingFisher automated DNA extraction robot (Table 2).

Sampling information of Philodoria species used for molecular analysis.

Species name Collection site Host plant species Host plant family Collection ID BOLD ID BOLD BIN GenBank accession no. Institution of DNA extraction and sequencing of COI
P. succedanea Hawaii Myrsine lessertiana Primulaceae RMNH.INS.30669 WOGRA451-17 ADF5435 MF804823 RMNH, Netherlands
P. succedanea West Maui M. lessertiana Primulaceae CJ-144 WOGRA489-17 ADF5435 KT982414 FLMNH, USA
P. kauaulaensis West Maui M. lessertiana Primulaceae CJ-064 WOGRA487-17 ADI5327 KT982404 FLMNH, USA
P. kauaulaensis West Maui M. sandwicensis Primulaceae CJ-072 WOGRA488-17 ADI5327 KT982407 FLMNH, USA
P. auromagnifica Hawaii M. lessertiana Primulaceae RMNH.5013750 WOGRA444-17 ADD6965 MF804828 RMNH, Netherlands
P. auromagnifica Hawaii M. lessertiana Primulaceae CLV6240 LEPPC2422-16 ADD6965 MF804824 CCDB, Canada
P. kolea Hawaii M. lessertiana Primulaceae IO-322 WOGRA440-17 ADF7137 MF804825 KPU & Eurofins, Japan
P. kolea Hawaii M. lessertiana Primulaceae RMNH.INS.30682 WOGRA449-17 ADF7137 MF804831 RMNH, Netherlands
P. kolea Hawaii M. lessertiana Primulaceae RMNH.5013751 WOGRA447-17 ADF7137 MF804834 RMNH, Netherlands
P. kolea Hawaii M. lessertiana Primulaceae RMNH.5013752 WOGRA448-17 ADF7137 MF804832 RMNH, Netherlands
P. kolea Hawaii M. lessertiana Primulaceae RMNH.INS.30684 WOGRA450-17 ADF7137 MF804830 RMNH, Netherlands
Philodoria sp. nr. floscula Hawaii Pipturus sp. Urticaceae CLV6239 LEPPC2421-16 ADD6964 MF804826 CCDB, Canada
Philodoria sp. nr. splendida Kauai Unknown Unknown AYK-HI10-002 LNOUC1237-11 AAY7555 MF804829 FLMNH, USA
Philodoria sp. nr. splendida Kauai Unknown Unknown AYK-HI10-001 LNOUC1236-11 AAY7555 MF804827 FLMNH, USA
P. basalis Hawaii Metrosideros polymorpha Myrtaceae RMNH.INS.30680 WOGRA446-17 ADF5462 MF804833 RMNH, Netherlands
P. basalis Hawaii M. polymorpha Myrtaceae RMNH.5013753 WOGRA445-17 ADF5462 MF804835 RMNH, Netherlands

We conducted an ML analysis of the COI gene using RAxML 8.2.10 (Stamatakis 2014), searching for the best tree using the GTRCAT model and GAMMA-based likelihood optimization for the final tree, and otherwise default settings. Subsequently, 1,000 parametric bootstrap analyses with automated stopping following the extended majority rule criterion were performed to calculate branch support values. Phylogenetic trees were visualized in FigTree 1.4.3 (Rambaut 2009). Intra- and interspecific genetic distances were estimated using the Kimura 2-parameter model implemented within the analytical tools available in BOLDv4 (Table 3). We also used BOLD to obtain Barcode Index Numbers (BINs) (Ratnasingham and Hebert 2013).

Intra- and interspecific genetic divergences in DNA barcode sequences among studied Philodoria species.

Species P. succedanea P. kauaulaensis P. auromagnifica P. kolea P. basalis Philodoria sp. nr. splendida
P. succedanea [0.88]
P. kauaulaensis 7.0 [0.17]
P. auromagnifica 6.71 5.85 [0.31]
P. kolea 8.91 7.38 8.43 [0.30]
P. basalis 11.12 11.08 10.59 13.28 [1.70]
Philodoria sp. nr. splendida 13.46 12.10 12.19 13.83 4.41 [1.07]
Philodoria sp. nr. floscula 13.46 15.07 14.78 15.90 13.84 14.93

While single-marker COI analyses can be prone to insufficient resolution and error (Rubinoff and Holland 2005), we were unable to obtain additional genetic data for these species during the time of this study. We therefore chose to use a gene-tree based approach (Hebert et al. 2003; Hajibabaei et al. 2007) as another source of evidence to complement morphology to assess species limits. Sequences, voucher data, images, and trace files are deposited in the Barcode of Life Data Systems (BOLD) (Ratnasingham and Hebert 2007; www.barcodinglife.org). Furthermore, all sequences are deposited in GenBank, and are available as a single dataset DS-PHDRIA (http://dx.doi.org/10.5883/DS-PHDRIA)

Voucher specimen numbers

Institutional voucher numbers are given here for primary type material and museum collections. In the cases of NHMUK/BMNH numbers, for clarity and consitency they are cited without a space nor hash symbol (#) that might be read between the alpha and numeric parts of the code, since spaces and hashes create ambiguity for search, and series of institutional numbers have appeared in the past with or without such symbols

Abbreviations for collections:

BPBM Bernice P. Bishop Museum, Department of Zoology, 1355 Kalihi Street, Honolulu, Hawaii 96818, USA.

FLMNH McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.

NHMUK Natural History Museum, Department of Zoology, Cromwell Road, London SW7 5BD, United Kingdom (formerly the British Museum [Natural History] or BMNH).

RMNH Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, Netherlands.

USNM National Museum of Natural History, Smithsonian Institution, 10th St. & Constitution Ave. NW, Washington, DC 20560, USA.

Results

Key to adults

1 Forewing leaden grey, externally with fuscous brown (Fig. 3) P. kolea sp. n.
Forewing shiny, metallic bronze with bright to dark orange patches 2
2 A bright orange transverse fascia at 3/4 in middle interrupted with blue patch; an orange medial transverse fascia, narrowing towards dorsum, (Figs 5I, J, 10E, F) P. kauaulaensis sp. n.
An orange transverse patch beyond middle to costal 3/4, narrowing towards dorsum, extending to dorsal 2/3, with white costal spot 3
3 A black patch along costal fold (Figs 5C, D); a fuscous patch near apex (Figs 1A, B, 8A) P. succedanea
An orange patch along costal fold, fringed with blackish scales (Figs 1E, F, 5F, H); a fuscous patch with dark orange scales at apex P. auromagnifica

Key to male genitalia*

1 Saccus slender, curved toward dorsum (Fig. 6B); vinculum small and inflexed on the ventral side (Fig. 6C) P. succedanea
Saccus broad and straight (Fig. 6F, J); vinculum large and inflexed on the ventral side (Fig. 6G, K) 2
2 Valva slightly narrowing in middle with terminally rounded dorsal process (Fig. 6E) P. auromagnifica
Valva with short, pointed dorsal process (Fig. 7A) P. kolea sp. n.
*Male of kauaulaensis is unknown.

Key to female genitalia

1 Signa with minute spines (Fig. 7I) P. kolea sp. n.
Signa with a pair of larger spines 2
2 Spines long and slender (Fig. 7E, F) P. succedanea
Spines on the signa small and rounded (Fig. 7H) P. kauaulaensis sp. n.
Spines on the signa blunt (Fig. 7G) P. auromagnifica

Key to leaf mines

1 Start of mine spiral-shape (Fig. 10B, C). Mines on Myrsine lanaiensis, M. lessertiana, M. sandwicensis; Maui P. kauaulaensis sp. n.
Start of mine linear or serpentine-shape 2
2 Reddish brown long linear mine following leaf vein (Fig. 9D–F), mature larvae in fallen leaves (Fig. 9A). Mines on M. knudsenii, M. lessertiana, M. linearifolia, M. sandwicensis; Kauai, Oahu, Lanai, Maui, Hawaii P. succedanea
Brown serpentine mines, mature larvae in situ leaves 3
3 Larvae utilize leaves on larger plants. Mines on M. lessertiana, M. sandwicensis, M. wawraea; Kauai, Oahu, Molokai, Hawaii P. auromagnifica
Larvae utilize leaves on seedlings (Figs 12A, E, 13D). Mines on M. lessertiana; Hawaii (Big Island) P. kolea sp. n.

Philodoria succedanea Walsingham, 1907

Figs 2A–D, 5A–D, 6A–D, 7E, F, 8A, 9, 14A

Philodoria succedanea Walsingham, 1907: 717–718; pl. 25, fig. 19.

Philodoria (Philodoria) succedanea Walsingham, 1907: Zimmerman 1978: 718, figs 433, 435, 467, 472.

Type locality

Olinda, Haleakala (Maui).

Type material

Lectotype ♀, Olinda, 4000 ft., Haleakala, MAUI, Hawaiian Is. iv.1894, Perkins. 26695 [Walsingham specimen number]|PHILODORIA SUCCEDANEA Wlsm. Fn. Hawaii. I TYPE ♀ descr. figd.|Walsingham Collection. 1910-427.|NHMUK010305341 (here designated).

Paralectotypes 17 (2♂ 1♀ 14 unsexed; NHMUK ones are all from above Walsingham accession and ‘PARATYPE’ below is short for ‘PHILODORIA SUCCEDANEA Wlsm. PARATYPE’ as printed on large black-margined labels, with the 5-digit Walsingham specimen numbers whose first digit is ‘2’ borne on the locality label): 1 ♂, Haleakula 4000 ft. MAUI, Hawaiian Is. V. 1896|Perkins. 28505|PHILODORIA SUCCEDANEA Wlsm. Fn. Hawaii. I TYPE ♂|BM ♂ Genitalia slide no. 2755|NHMUK010305341. 1♀ 2 unsexed: Haleakala, 5000ft, MAUI, Hawaiian Is., v.1896, Perkins. 28355|PARATYPE 3/17|NHMUK010862804|; 28230|PARATYPE 4/17♀|BPBM 34324; 28236|PARATYPE 5/17|BPBM 34321. 4 unsexed: Haleakula -4000 ft. Maui, v. 1896, Perkins. 28492|PARATYPE8/17; 28493|PARATYPE 9/17|BPBM 34320|; 28494|PARATYPE10/17|NHMUK010862806; 28495|PARATYPE 11/17|NHMUK010862807.

1 ♂ 7 unsexed, same data and locality as lectotype: 26696|NHMUK010862803; 26661|PARATYPE1/17|BPBM34325; 26667|PARATYPE2/17|BPBM 34222; 28511|PARATYPE12/17|NHMUK010862808; 28512|PARATYPE13/17|NHMUK010862809; 28513|PARATYPE14/17|NHMUK010862810; 28514|PARATYPE15/17♂|NHMUK010862811; 28552|PARATYPE 16/17|BPBM 34323.

This species was described from 19 specimens: ‘type ♀ (26695); ♂ (28505)’ and 17 ‘paratypes’ from Kauai and Haleakala, Maui. This seems to indicate that Lord Walsingham considered them as holotype, allotype, and paratypes, as indicated on their specimen labels. But as a holotype was not specified in the description, the so-labelled types and paratypes are all to be considered syntypes under the present Code, Article 73.2 (ICZN 1999), and any one is thus eligible for designation as lectotype. The syntype ‘type ♀ (26695)’, which Walsingham listed first and figured, is here designated as lectotype (Fig. 2A). The remaining syntypes are therefore paralectotypes.

Figure 2. 

Adults of Myrsine-feeding Philodoria species. A–D P. succedanea Walsingham, 1907 A Lectotype female B Paralectotype male C Paralectotype female D Male Lanai E–F P. auromagnifica Walsingham, 1907 E Holotype male F Female Kauai. Scale bar: 1 mm.

Additional material

32 (11♂ 15♀ 6 unsexed).

Adults: Oahu Is.: 2♀, Mt. Kaala, 18.ii.1923, Swezey coll., host: “Suttonia” (= Myrsine), SK797♀, 798♀ in USNM; 3♂ 3♀, Palikea, 28.iii.2016 stored in 99 % ethanol (stored), K. Bustamente leg., host: M. lessertiana, 10.xi.2015, CJ-526, CJ-531, SK639♂, SK803♀, 804♀, 807♂, 808♂ in BPBM.

Molokai Is.: 1♀, Kainalu [Kainalu Forest, South East Molokai Forest Reserve], 27?vii.1927, Philodoria auromagnifica Walsingham Det. by O.H. Swezey, 34145 in BPBM; 1 unsexed, 4000 ft Molokai P. 2.02 Philodoria succedanea Wals. 1/1 E. Meyrick det. in Meyrick coll., in NHMUK.

Lanai Is.: 2♂, 2750 ft, Munro Trail, 2.x.1976, K. & E. Sattler BM1976-605, BMNH(E)1621676 and BMNH(E)1621677, Philodoria sp. 8 (Lanai) Sattler coll. D.C. Lees Sep 2016.

Maui Is., in BPBM: 1♂ 6♀ 1 unsexed, below Eke, 17&21.v.2013 (stored), C.A. Johns leg., host: Myrsine sp., 24.iv.2013, CJ-136, 141, SK799♀; 1♂, Waikamoi, 24.v.2016 (stored), C.A. Johns leg., Spring.2016, CJ-539, SK641♂.

Hawaii Is., host: M. lessertiana in BPBM: 1♂ 1♀, Hawai’i Volcanoes National Park, Hawaii, A. Kawakita leg., “Leaf-dropper”, 25.iv.2016 (larva), SK624♀, SK625♂; 2♂ 1♀ 1 unsexed, Same locality, 17&21.v.2016 em., A.Y. Kawahara leg., 29.iv.2016(Cocoon & larva), SKH-10, SK801♂, SKH-13, SK633♂. 1♀, 3800 ft, N. Kohala, Distr. Kohala Mts, Puu Laalaau area, 14–17.vii.1976, K. & E. Sattler, BM1976-605, BMNH(E)1621089, Philodoria sp. 9 (Hawaii) Sattler coll. D.C. Lees Sep 2016, 1621676 in NHMUK; 1♂, same data as last specimen, BMNH(E)1621090, Philodoria sp. 9 (Hawaii) Sattler coll. D.C. Lees Sep 2016; 1 unsexed, Kohala Watershed Partnership, 9.vi.2015 (stored), C.A. Johns leg., host: Myrsine sandwicensis, 18.v.2015, CJ-419 in BPBM.

Larvae: 2 unsexed, Kokee, Kauai Is., 16&26.vi.2015 (stored), C.A. Johns leg., host: M. knudsenii 15.vi.2015 (larva), CJ-433, 442 in FLMNH.

Diagnosis

This species is very similar to P. auromagnifica feeding on the same hostplant, Myrsine, but is recognizable by the rather bright orange patches and black triangular shaped basal patch in the forewing (Table 4; Figs 2A–D, 5A–D); in the male genitalia by the rather broad valva, slender and long saccus curving toward dorsal side (Fig. 6A–C); in the female genitalia by signa with slender and long spines (Fig. 7E, F).

Diagnostic features of four Myrsine-mining Philodoria species.

Species name P. succedanea P. kauaulaensis P. auromagnifica P. kolea
Forewing Shiny, metallic bronze with bright orange-ochreous Similar to P. succedanea Shiny, metallic bronze with dark brownish orange Leaden grey, externally with brownish fuscous
Basal patch Black, triangular-shape Absent, orange transverse fascia from costal fold to dorsal 1/4 Brownish orange with black ground color, sometimes black Brownish fuscous
Apical orange transverse fascia Absent Present Absent Absent
Apical portion Fuscous, sometimes orangish encroaches on the apex Fuscous Fusocus with dark orange scales Leaden gray
Genitalia
Valva Broad Unknown Rather long and narrowing in the middle having rather shorter and pointed dorsal process
Vinculum Small, inflexed on the ventral side Unknown Large, inflexed on the ventral side Small, inflexed on the ventral side
Saccus Slender and long, curved toward dorsal side Unknown Broad and straight Broad and straight
Spine on signum Long and slender Rather smaller and rounded Rather blunt Minute
Distributiona,b Kauai, Oahu, Lanai, Maui, Hawaii Maui Kauai, Oahu, Molokai, Hawaii Hawaii
Host plant speciesa,b Myrsine lessertiana, M. sandwicensis, M. knudsenii, M. linearifolia, Myrsine sp. Myrsine lessertiana, M. lanaiensis, M. sandwicensis Myrsine lessertiana, M. sandwicensis, M. wawraea, Myrsine sp. Myrsine lessertiana
Larval habit type Leaf dropper Unknown (probably non leaf dropper) Non leaf dropper Non leaf dropper
Mining form Long, linear, along leaf vein At first spiral, later blotch Serpentine Serpentine
Mine color Red Brown Brown Brown

Redescription

Adult (Figs 2A–D, 5A–D, 8A). Wingspan 9–10 mm in type series; forewing length 4 mm in 'TYPE ♂ (28505)' (fig. 2B), 3.6–3.8 mm in paralectotypes. Head bronze; frons white; maxillary palpus reduced; labial palpus bronze grey, with dark brown scales at apex. Antenna shiny tawny fuscous. Thorax bronze.

Forewing shiny, metallic bronze with bright orange-ochreous patches: a black triangular basal patch along the costal fold (Figs 5A, C, 8A); an oblique transverse fascia before the middle of wing, bordered with black scales; a large transverse patch after the middle to costal 3/4, distinctly narrowing in the dorsum, extending to dorsal 2/3, containing white costal spot; one white color band on the middle of the first bronze color band, others on both extremities of second and third bands; a fuscous patch extending toward the termen and apex with a black apical spot, sometimes with orange-ochreous color encroaching on the apical part; cilia tawny, with two metallic silver basal lines, one at the apical cilia, another from termen to tornus. Hindwing dark tawny; cilia tawny. Abdomen tawny above, silvery beneath. Legs tawny, with silvery spurs and slightly paler tarsi.

Male genitalia (Fig. 6A–D) (n = 7). Capsule 960 µm. Uncus absent. Tegumen 570–580 µm long, 1.2–1.3× length of valva with series of long hairs at lateral side of base (Fig. 6C). Tuba analis membranous with weakly sclerotized subscaphium; gnathos V-shaped transverse band, terminal margin weakly joining subscaphium and anterior process connecting ventral base of tegumen. Valva broad, 430 µm in length covered with fine setae distally, and having a short dorsal process (Fig. 6A).Vinculum U-shaped; saccus 250 µm long, slender , curved toward dorsal side (Fig. 6B, C). Phallus 720 µm long, tubular and long about 1.2–1.3× length of valva, sinuous in lateral view with two series of minute spiniform cornuti in vesica; coecum slightly curved toward inner side (Fig. 6D).

Female genitalia (Fig. 7E, F) (n = 7). Ostium bursae rather small, opening at the middle of 7th abdominal segment; antrum cup-shaped with slender a pair of lateral lobes; ductus bursae slender, tubular, extremity connected to antrum very slender and membranous, curved inside of body, and middle part weakly sclerotized and plate-shape; end of the ductus bursae broad; inception of ductus seminalis on the posterior part of ductus bursae. Corpus bursae pyriform, anterior end weakly sclerotized; some lines consisting of wrinkles running longitudinally, some sclerotized; paired signa with a pair of long slender spines.

Figure 3. 

Adults of P. kolea sp. n. A holotype male B Paratype female. Scale bar 1 mm.

Figure 4. 

Distribution of Myrsine-feeding Philodoria species. The star indicates the type locality of each species. Information based on this study and label data of specimens in BPBM, USNM, and NHMUK. Symbols are numbered according to showing locality in Table 1 and alphabetical symbols (A–K) correspond to figure numbers in Figure 5.

Figure 5. 

Forewing coloration and pattern of Myrsine-feeding Philodoria species. A–D P. succedanea E–H P. auromagnifica I, J P. kauaulaensis K, L P. kolea. A–C, E–G, K Hawai’i Volcanoes National Park. A Female SK622, leaf-dropper B Male SK625, leaf-dropper C Male SK633 D Paralectotype female 34320 Haleakala, Maui in BPBM E Female SK624, non-leaf-dropper F Female SK623, non-leaf-dropper G Male SK805 H Female Z-XII-20-62-6 34143 Wailupe, Oahu, in BPBM I, J Holotype female SK690 K Paratype female SK632 L Paratype female SK631. Scale bars: 1 mm.

Figure 6. 

Male genitalia of Philodoria. A–D P. succedanea Maui SK641 E–H P. auromagnifica Hawaii SK800 I–L P. auromagnifica Kauai SK689 A, E, I Left valva B, F, J Genital capsule lateral view C Genital capsule with left valva ventral view G, K Genital capsule ventral view D, H, L Phallus lateral view. Abbreviations: co: cornuti; gn: gnathos; sa: saccus; ss: subscaphium; ta: tuba analis; te: tegumen; va: valva; vi: vinculum.

Figure 7. 

Genitalia of Philodoria. E–I Female. A–D P. kolea holotype male Hawaii SK851 E P. succedanea paralectotype Maui SK714 F P. succedanea leaf dropper Hawaii SK624 G P. auromagnifica non leaf dropper Hawaii SK623 H P. kauaulaensis holotype SK690 I P. kolea paratype Hawaii SK634. A Valva B Genital capsule lateral view C Genital capsule ventral view D Phallus lateral view

Distribution

Kauai, Oahu and Lanai: new record, Maui (Walsingham 1907), Molokai and Hawaii (Big Island) (Zimmerman 1978).

Host plants

Primulaceae: Myrsine sandwicensis A. DC., M. lessertiana A. DC. (Johns et al. 2016), Myrsine sp. (Zimmerman 1978). Myrsine linearifolia Hosaka and M. knudsenii (Rock) Hosaka are new host records (see Remarks).

Biology

(Figs 8A, 9, 14A). The larvae mine the adaxial side of leaves of Myrsine species, forming a long linear mine (Fig. 9B, G, H). The mine is at first tornus-shaped (Fig. 9C, D, I, J) and the larva broaches the mid vein towards the petiole of the leaf, forming a straight mine; the vein mine and surrounding pattern are red in coloration (Fig. 9F, H) and later instars leave the mid vein usually near the base of the leaf, gradually expanding as they feed and grow forming a full-depth mine (Fig. 9E, F). There were usually one to two mines per leaf (Fig. 9B, G, M). The pupal cocoon is situated outside of the mine, usually on the leaf surface, and also on the woody tissue of the host plant with leaf mines and larvae. At Hawai’i Volcanoes National Park, larvae were collected from leaves that had fallen to the ground and reared to adulthood (Fig. 9A). The adult has been observed during the day (Maui and Hawaii Island), resting on the upper leaf surface of the host plant (Fig. 8A).

Figure 8. 

Resting posture of adult Philodoria. A P. succedanea Waikamoi Maui B P. auromagnifica Molokai CJ241.

Figure 9. 

Biology of Philodoria succedanea with its hostplant, Myrsine lessertiana. A–J Hawai’i Volcanoes National Park, Hawaii (Big Island) K–N Maui A Fallen leaf and leaf mine with larva B Hostplants and leaf mines C, I, J Young mine D Leaf vein mine E–G Mine by late instar larva H, K, M Mature larva and mine N Mature larva O Adult, CJ-145, lateral view.

DNA barcoding

BIN BOLD:ADF5435. The two specimens sequenced for COI, one from Maui and one from Hawaii, have identical DNA barcode sequences. The p-distance to the nearest neighbor, P. kauaulaensis, is 6.63%.

Remarks

We identified two adult moths (Coll ID CJ-144 / GenBank accession no. ID KT982414 and CJ-145) as P. succedanea, based on the presence of a basal black patch on forewing, from which whole bodies were sacrificed for molecular analysis (Johns et al. 2016; Figs 6O, 12). Zimmerman (1978) did not recognize Walsingham’s (1907) Kauai record of this species because Walsingham had only one specimen at hand, which was in poor condition (specimen data: 1 ♂, Mts [which Mts not further specified], 3–4000 ft., Kauai, vi. 1894 Perkins.27297| PARATYPE 17/17 (?)|‘NOT succedanea Det. by E. C. Zimmerman|NHMUK010862812). We could not find the specimen from Kauai. However, we found Myrsine knudsenii (Endangered, IUCN) leaves with mines with active larvae from Kokee, Kauai Is. (CJ-433, 442), which were similar in appearance to mines of P. succedanea on M. lessertiana. Judging from these data, we consider the larval mines on M. knudsenii were made by P. succedanea. We also collected active Philodoria leaf mines from M. linearifolia (Endangered, IUCN) at the same location as M. knudsenii, but were unable to rear adult moths. It is thus possible that P. succedanea also mines M. linearifolia, but this needs to be further examined.

Philodoria kauaulaensis Kobayashi, Johns & Kawahara, sp. n.

Figs 5I, J, 7H, 10, 14B

Type locality

Kauaula (Maui).

Type material

Holotype ♀, Kauaula, Maui, 18.viii.2014 (stored in 99% ethanol), C.A. Johns leg., host: Myrsine lanaiensis, 31.vii.2014, CJ-381, SK690 in BPBM. The holotype is incomplete but we consider it distinctive enough to be worth describing. What remains of the holotype was mounted by placing three wings without mountant under a coverslip: two forewings (3/4 of right wing and half of left wing), and the apical portion of one hindwing (Fig. 5I). The head, antenna, thorax, and legs were sacrificed for molecular analysis.

Additional material

2 unsexed (CJ-064, CJ-072), entirely sacrificed for molecular analysis and belonging to BIN BOLD:ADI5327 (See Remarks): 1 unsexed, Haelaau, Maui, 26.iv.2013 (stored), C.A. Johns leg., host: M. lessertiana, 8.iv.2013, CJ-064, KT982404; 1 unsexed, Haelaau, Maui, 29.iv.2013 (stored), C.A. Johns leg., host: M. sandwicensis, 8.iv.2013, CJ-072, KT982407.

Diagnosis

The forewing pattern of this species is similar to that of P. succedanea, but differs from the latter by having broad orange transverse fasciae (Fig. 10E, F) and a white and bronze band near the apical portion of wing, in the middle interrupted by a blue patch (Fig. 5I, J).

Figure 10. 

Biology of Philodoria kauaulaensis with its hostplant, Myrsine lessertiana, Haelaau, Maui, CJ-064. A, B Hostplant leaves and mines C Spiral mines, cocoon and adult moth D Cocoon with pupal exuvia E Resting posture of adult F Dead adult. Arrow showing leaf mine.

Description

Adult (Fig. 5I, J). Forewing length 2.4 mm, basal part of holotype forewing missing. Descriptions of the basal forewing and part of the body were based on photographs of adult moths (CJ-064, 072). Head and frons fuscous; maxillary palpus unknown; labial palpus ochreous. Antennae dark fuscous. Thorax unknown. Forewing shiny, metallic bronze with three large bright orange transverse fascia: an oblique one from costal fold to dorsal 1/4; a second at the middle of wing, narrowing greatly in the dorsum, containing a white costal spot; a third at 3/4 in the middle, interrupted by a blue patch; all fascia bordered with black scales: one white color band at middle of the first bronze color band, others on both extremities of third and fourth bands; a fuscous patch extending toward termen and apex with a black apical spot; cilia shiny, dark bronze grey. Hindwing dark tawny fuscous. Abdomen fuscous above, whitish beneath.

Male genitalia. Unknown.

Female genitalia. (Fig. 7H) (n = 1). Similar to P. succedanea and P. auromagnifica, but different in having rather smaller and rounded spines on the signa.

Distribution

Maui.

Host plants

Primulaceae: Myrsine lanaiensis Hillebr., M. lessertiana A. DC., and M. sandwicensis A. DC.

Biology

(Figs 10, 14B). The mine is initially spiral-shaped (Fig. 10B, C) and gradually expands as the larva feeds and the mine later gets the form of a blotch (Fig. 14B). The pupal cocoon is situated outside the mine, usually on leaf surface (Fig. 10D).

DNA barcoding

BIN BOLD:ADI5327. The two specimens sequenced for COI are from Maui and have a 0.17 p-distance between them, the p-distance to the nearest neighbor, P. auromagnifica, is 5.58%.

Etymology

The specific epithet is derived from the type locality, Kaua`ula (pronounced ‘cow-wa-u-la’) Valley, an important site for Hawaiian endemic plants and culturally and spiritually for Native Hawaiians.

Remarks

Johns et al. (2016) collected larvae from Myrsine lessertiana and M. sandwicensis in West Maui and identified the reared adult moths as P. auromagnifica (Coll. ID CJ-064 / GenBank accession no. KT982404 and CJ-072 / KT982407). Comparison of adult morphology and larval behavior with other species shows that these moths belong to P. kauaulaensis (Figs 10, 14). Unfortunately these specimens were sacrificed for molecular analysis, so that they cannot be added to the type series.

Philodoria auromagnifica Walsingham, 1907

Figs 2E, F, 5E–H, 6E–H, 7G, 8B, 11, 14C

Philodoria auromagnifica Walsingham, 1907: 718, pl. 25, fig. 20; Swezey 1913b: 223.

Philodoria (Philodoria) auromagnifica Walsingham, 1907: Zimmerman 1978: 695, figs 461, 468, 474.

Type locality

mountains, 2000 ft near Honolulu (Oahu).

Type material

Holotype ♂, Mts. 2000 ft near Honolulu, Oahu, 25.x.1892, Perkins. 25857|BM slide no. 472|Walsingham Collection. 1910–427.|NHMUK010305330| in NHMUK. This species was described based on a single specimen from Oahu. The ‘type’ specimen, designated by Walsingham is here thus the holotype following article 73.1.2 (ICZN 1999).

Additional material

22 (8♂ 11♀ 3 unsexed)

Kauai Is: 1♂, Mt. Kahili, 18.vi.2013 (stored), N. Tangalin leg., Nat Collection, host: M. wawraea, CJ-148, SK689♂ in BPBM; 1♀, 4000 ft, Kokee State Park, Kahuamaa Flat, 21.viii.1973|K. & E. Sattler, BM1973-498|BMNH(E)1621087|Philodoria sp. 5 (Kauai) Sattler coll. Colour slide 67, D.C. Lees Sep 2016 in NHMUK; 1♂, same data labels as last specimen but 28.viii.1973|67|BMNH(E)1621087; 2 unsexed, Kauai, 3600’, Kokee State Park Kaumuohua Ridge (Milolii Ridge Rd) 1.vii.1982|K. & E. Sattler, BM1982-342| BMNH(E)1621081; same data, but BMNH(E)1621088; 1♂, Kauai, 3800’, Kokee State Park Kumuwela Ridge Waininiua Trail 24,vi.1982|K. & E. Sattler, BM1982-342|BMNH(E)1621091.

Oahu Is: 1♂, Kahana, 1.i.1928, O.H. Swezey Collector, “Suttonia“(= Myrsine), Z-XII-20-62-5♂, BPBM no. 34142 in BPBM; 2♀, Olympus, Coll. O.H.S, ex Myrsine, 33, J.F.G.C. #3801♀ in USNM. 1♀, Wailupe, 11.i.1925, O.H. Swezey Collector, “Suttonia“(= Myrsine), Z-XII-20-62-6♀, 34143 in BPBM.

Molokai Is, in BPBM: 1 unsexed, Kawela, 3700ft, 23.xii.1925, O.H. Swezey Collector, “Suttonia”(= Myrsine), 34144;1♂, Kamakou Boardwalk, 24.i.2014 (stored), C.A. Johns leg., host: M. lessertiana, 18.xii.2013, CJ-241, SK768♂ in BPBM.

Hawaii Is., Hawai’i Volcanoes National Park, host: M. lessertiana in BPBM: 2♀, A. Kawakita leg., “Non-leaf-dropper”, 25.iv.2016 (larva), SK622♀, SK623♀; 3♂ 4♀, 17–24.v.2016 em., A.Y. Kawahara leg., 27&29.iv.2016 (Cocoon & larva), SKH-10, SK802♀, SKH-13, SK805♂, AYK0002, SK806♂, HILO053, SK800♂, HILO054, SK811♀, HILO059, SK810♀; 1♀, Lava tube, 15.v.2016 em., C.L.-Vaamonde & C. Doorenweerd leg., 22.iv.2016, HILO020/AYK0001, SK809♀.

Diagnosis

This species is very similar to P. succedanea, but recognizable by the dark brownish orange patches and brownish orange basal patch in the forewing; a fuscous patch with dark orangish scales in the apical portion (Table 4; Figs 2E, F, 5E–H); in the male genitalia by the rather long valva narrowing in the middle, vinculum large, inflexed on the ventral side, broad and straight saccus (Fig. 6E–G); in the female genitalia by signa with rather blunt spines (Fig. 7G). See also diagnosis of P. succedanea.

Redescription

Adult (Fig. 2E, F). Wingspan 8 mm in holotype, 7–9 mm in other specimens; forewing length 3.5 mm in holotype, 3.2–3.9 mm in others. Head and frons dark steely fuscous; maxillary palpus reduced; labial palpus ochreous to brown. Antenna dark fuscous. Thorax: dark brownish orange, becoming fuscous posteriorly. Forewing shiny, metallic bronze with dark brownish orange patches: a large one at base bordered with black ground color (Figs 2E, F, 5E, F, H), sometimes missing orange color (Fig. 8B); an oblique transverse fascia before the middle of wing, bordered with black ground color, sometimes missing orange color (Fig. 11A); a large transverse patch after the middle to costal 3/4, narrowing greatly in the dorsum, extending to dorsal 2/3, containing a white costal spot; one white color band on the middle of the first bronze color band, others on both extremities of second and third bands; a fuscous patch mixed with dark brownish orange scales extending toward the termen and apex with a black apical spot; cilia shiny, dark bronze grey. Hindwing dark tawny fuscous. Abdomen and legs fuscous above, white beneath.

Figure 11. 

Biology of Philodoria auromagnifica with its hostplant. A Resting posture of adult male, host: Myrsine wawraea Kauai CJ-148 B, C Later mine, host: M. lessertiana Hawai’i Volcanoes National Park, Hawaii.

Male genitalia (Fig. 6E–L) (n = 5). Capsule 940–980 µm. Tegumen 540–580 µm long. Similar to P. succedanea except tegumen 1.2× length of valva; valva 460–480 µm long, broad and slightly narrowing in the middle (Fig. 6E, I); vinculum large, inflexed on the ventral side (Fig. 6G, K); saccus 300 µm long, broad and straight (Fig. 6F).

Female genitalia (Fig. 7G) (n = 7). Similar to P. succedanea, but different in having rather slender tapering antrum and rather blunt spines on the signa.

Distribution

Kauai: new record, Oahu (Walsingham 1907), Molokai (Swezey and Bryan 1929), and Hawaii (Big Island) (Zimmerman 1978).

Host plants

Primulaceae: Myrsine sp. (Swezey 1913a), M. lessertiana A. DC. and M. sandwicensis A. DC. (Johns et al 2016), M. wawraea (Mez) Hosaka: new record.

Biology

(Figs 8B, 11, 14C). The larvae mine the adaxial side of leaves of Myrsine species, forming a long serpentine mine (Fig. 11B) and gradually expanding as they feed (Figs 11C, 14C2, C3). Old mines are ocherous to brown in coloration (Fig. 14C1). There were usually one to two mines per leaf (Fig. 11B). The pupal cocoon is prepared outside the mine, on either surface of the leaf, and one was found on the bark of the host.

DNA barcoding

BIN BOLD:ADD6965. The two specimens sequenced for COI are from Hawaii and diverge by 0.31%, whereas the p-distance to the nearest neighbor, P. kauaulaensis, is 5.58%.

Parasitoids

Euderus metallicus (Ashmead, 1901), Eulophidae (Zimmerman 1978).

Remarks

We collected Philodoria leaf mines from Myrsine plants on Kauai Island (See also remarks for P. succedanea), only one male adult identified as P. auromagnifica emerged from a larva that fed on M. wawraea (Fig. 14C3). The Kauai specimens have a black second transverse fascia (Fig. 11A), but male genital variation that we observed appears to be intraspecific (Fig. 6I–L). Some specimens have a oblong valva which narrows in the middle (Fig. 6I), while others have a long tegumen about same length of valva, and slender vinculum and saccus in ventral view (Fig. 6J, K). We notice some wing pattern variation between islands, particularly in the extent of the orange forewing markings, and detailed DNA barcoding in future may prove revealing as regard the integrity of this species as we recognize it here. Two barcoded specimens collected from Hawaii (Big) Island (RMNH.5013750, CLV6240) belong to the same BIN (BOLD:ADD6965).

Philodoria kolea Kobayashi, Johns & Kawahara, sp. n.

Figs 3, 5K, L, 7A–D, I, 12, 13, 14D

Type locality

Hawai’i Volcanoes National Park (Big Island).

Type material

Holotype ♂, Hawai’i Volcanoes National Park, Hawaii (Big Island), 25.iv.2016, A. Kawakita leg., host: Myrsine lessertiana (understory shrub), GenBank accession no. MF804825, IO-322, SK851 in BPBM. The type series was mounted from emerged adult moths.

Paratypes, in BPBM: 1♀, Kaumana Trail, Hilo, Hawaii (Big Island), 28.iv.2016, em., C.L.-Vaamonde & C. Doorenweerd leg., host: Myrsine sp., 20.iv.2016 (Cocoon), HILO016, SK634♀. 1♀, Thurston lava tube (Nahuku), Hawai’i Volcanoes National Park, Hawaii Is., 13.v.2016, em., S. Kobayashi leg., host: Myrsine lessertiana, 25.iv.2016 (larva), SKH-05-1, SK632♀; 1♀, same locality and data as holotype, IO-323, SK852; 2♀, same locality as holotype, 2&24.v.2016, em., C.L.-Vaamonde & C. Doorenweerd leg., host: Myrsine lessertiana, 22.iv.2016 (larva), HILO020/SKH-15, SK630♀, 631♀.

Diagnosis

Among Philodoria species having similar fuscous forewing coloration (i.e., P. wilkesiella Swezey, P. pipturiana Swezey, P. epibathra (Walsingham), and P. nigrella (Walsingham) (See Zimmerman 1978)), the new species is recognizable by the white and bronze color bands on the forewing (Fig. 3). The forewing pattern and the genitalia are similar to those of other Myrsine mining species, P. succedanea and P. auromagnifica, but P. kolea completely lacks the orange markings (Figs 2, 3).

Description

Adult (Figs 3, 5K, L, 12N). Wingspan 6.7 mm in holotype, 6.6, 8.5 mm in paratypes; forewing length 3.0, 3.1 mm in holotype, 2.7–4.0 mm in paratypes. Head leaden grey; frons whitish grey; maxillary palpus reduced; labial palpus greyish ochreous, terminal joint with fuscous band at middle and at apex. Antenna greyish fuscous. Thorax leaden grey. Forewing base leaden grey, externally suffused with brownish fuscous patches: a triangular basal patch along the costal fold; an oblique transverse fascia before the middle of wing, bordered with black scales; a large transverse patch after the middle to costal 3/4, narrowing in the dorsum, extending to dorsal 2/3, containing small white costal spot; leaden grey small median line at base with dorsal narrow patch from base to near middle; one white color band at the middle of the first bronze color band, others on both extremities of second and third bands; a leaden grey patch extending toward the termen and apex with small shiny black apical spots; cilia leaden grey with a black fringe basal line; tonal cilia with a shiny white fringe basal line. Hindwing and cilia leaden grey. Abdomen greyish fuscous above, banded with white beneath. Legs pale greyish fuscous, spurs white.

Male genitalia (Fig. 7A–D) (n = 1). Capsule 830 µm. Tegumen 600 µm long. Similar to P. auromagnifica, except tegumen 1.5× length of valva (Fig. 7A, C); valva 390 µm long, broad and having rather shorter and pointed dorsal process (Fig. 7A); saccus 250 µm long. Phallus 640 µm long.

Female genitalia (Fig. 7I) (n = 5). Similar to P. succedanea and P. auromagnifica, but different in having two very small and narrow signa with minute spines.

Distribution

Hawaii (Big Island).

Host plants

Primulaceae: Myrsine lessertiana A. DC.

Biology

(Figs 12, 13, 14D). Larvae mine the adaxial side of leaves of M. lessertiana, forming a slender serpentine mine (Fig. 12A, B), and gradually expanding as they feed and grow forming a full-depth mine (Fig. 12G, L). Larvae consumed small amounts of leaf tissue (under 2 cm in leaf length) when feeding on seedlings (Fig. 13G, H). The young larva is about 1.5 mm long (Fig. 12I) and later instar larvae are 4–8 mm long (Fig. 12J, K). Larvae were collected from fresh leaves of seedlings. There was usually only one mine per leaf (Fig. 12A, B, G, H). The pupal cocoon is prepared outside the mine, on either surface of the leaf; the cocoon is greyish white to ochreous and near ellipsoidal in shape (Fig. 12M); 4.0–5.0 mm in length, 1.0–3.0 mm in width.

Figure 12. 

Biology of Philodoria kolea with its hostplant, Myrsine lessertiana. A–M Hawai’i Volcanoes National Park A–B, E Hostplant leaves and mines C Habitat and hostplants D Leaves and young mine F–H Later mines I Young larva J–L Mine by later instar larva M Cocoon N Resting posture of adult, paratype female lateral view.

Figure 13. 

Biology of Philodoria kolea and its host, on seedlings of Myrsine lessertiana. A Young mine B–C, E–F Mine by later instar larva G Mature mine and larva H Full mature mine. Arrows showing larvae.

Figure 14. 

Mine forms and characters of Philodoria species and their Myrsine host plants. A: long linear form via mid vein ; B: Spiral to blotch form; C, D: Serpentine form. A P. succedanea B P. kauaulaensis C P. auromagnifica D P. kolea A, C1–2, D M. lessertiana D1, 2 same collection of SKH-05-1 B1 M. lanaiensis, same collection of CJ-381 B2 M. sandwicensis, same collection of CJ-072 C3 M. wawraea, CJ-148. A Molokai B Maui C1–2, D Hawaii C3 Kauai.

Figure 15. 

Maximum likelihood tree of Philodoria species based on the DNA barcoding region. Numbers on nodes indicate bootstrap support values. Collection ID, host plant, and collection locality, are also shown.

DNA barcoding

BIN BOLD:ADF137. The five specimens sequenced for COI are from two localities on Hawaii and have maximum intraspecific p-distance of 0.17%. The p-distance to the nearest neighbor, Philodoria kauaulaensis, is 6.98%.

Etymology

The specific epithet, kolea, is a noun in apposition taken from the Hawaiian name of the host plant, Myrsine.

Molecular analysis

We obtained DNA barcode data for 16 individual specimens (http://dx.doi.org/10.5883/DS-PHDRIA). All species have their own unique cluster or Barcode Index Number (BIN) allowing their unequivocal identification (Table 2). The lowest interspecific distance (4.41%) was observed between Philodoria sp. nr. splendida and P. basalis (Table 3). Sequences of Myrsine-feeding Philodoria species, when compared pairwise, formed distinct clusters, with a maximum intraspecific divergence which varied between 0.17–0.88% and a NN distance which varied from 5.85–8.91% (Table 3). The minimum interspecific distance was smaller between P. auromagnifica and P. kauaukaensis (5.85%) than between P. auromagnifica and P. succedanea (6.71%) (Table 3). Identifying species using DNA barcodes appears to be useful for the Myrsine-feeding Philodoria. Philodoria succedanea belongs to BIN BOLD:ADF5435, P. kauaulaensis to BOLD:ADI5327, P. auromagnifica to BOLD:ADD6965, and P. kolea to BOLD:ADF7137.

Discussion

Hawaiian Philodoria leaf mining moths were extensively studied in the early 1910s–1940s by Otto Herman Swezey. However, little taxonomic work has been conducted since, and our investigation is revealing that several undescribed cryptic species remain to be discovered, as found in other Hawaiian micromoths (e.g., Bedellia, Bedelliidae: [Zimmerman 1978]; Hyposmocoma: Cosmopterigidae [Kawahara and Rubinoff 2012; Rubinoff 2008]). Philodoria is critically in need of taxonomic work considering the endemic distribution of its species on the Hawaiian islands, and the close association of the genus with native endemic and endangered host plants. Some host plants and their associated Philodoria have already become locally extinct (Johns et al. 2014).

Swezey collected Myrsine-feeding P. succedanea and P. auromagnifica from numerous localities on Oahu in the early 1900s. Myrsine lessertiana plants remain relatively abundant on Oahu, but Myrsine-mining Philodoria have become exceedingly difficult to find there, especially in the southeast where intense urban development has taken place over the last century. During our Oahu surveys, we were unable to find leaf mines on M. degeneri, M. fosbergii, M. juddii (Critically Endangered, IUCN), M. lanaiensis, M. pukooensis, M. punctata, or M. sandwicensis, despite extensive searches for leaf mines on these host plants. It is not clear whether these absences are more due to environmental changes causing population reductions than to original host plant restriction among Myrsine species.

On Maui, P. kauaulaensis and P. succedanea were found in April–May 2013 at two sites separated only by 3.3 km, below the summit of Eke and on Haelaau Ridge, within the Pu’u Kukui Watershed Preserve (Fig. 2A; Johns et al 2016, fig. 1, Coll. ID CJ-064, CJ-072). In the present study, we observed P. auromagnifica, P. kolea and P. succedanea occurring in sympatry on April 2016 at the Hawai’i Volcanoes National Park, the island of Hawaii (Big Island) (Figs 2A, 6A–J, 8B, C, 9A–M).

We collected larvae of P. auromagnifica (Fig. 8B, C) on plants that were also used by P. succedanea (Fig. 6A). The latter species was still mining leaves from the same plants that had fallen to the ground. Larvae of P. kolea occurred on leaves that were intact on short (about 10–20 cm high) Myrsine plants at the same site (Figs 9A, B, 10D). The genetic similarity between these species could imply that perhaps competition and niche partitioning may have been the cause of speciation. Fine-scale niche partitioning has been documented in other gracillariids and their host plants, such as Phyllocnistis on Persea (Davis and Wagner 2011) and Phyllocnistis on Salix (Kobayashi et al. 2011). Our ongoing research efforts will examine the evolutionary history and colonization patterns of Philodoria on the Hawaiian archipelago.

In addition to providing morphological and molecular evidence to delimit species limits among the Hawaiian Myrsine-feeding Philodoria, we include a pictorial key to their leaf mines (Fig. 14). We include this information as leaf mining moths can be difficult to observe as larvae or adults to a non-specialist. Larvae of P. succedanea form red, long linear mines along the leaf vein (Fig. 14A), P. kauaulaensis produces at first spiral and later blotch mines (Fig. 14B), P. auromagnifica makes brown serpentine mines (Fig. 14C), and P. kolea creates complete serpentine mines fully occupying the adaxial side of leaf surface of Myrsine seedlings (Fig. 14D). We hope that local Hawaiian park rangers, naturalists, and educators can use this key as a means to identify these species, so that the collection of these much-needed data can persist.

It is likely that detailed molecular work among islands will reveal further cryptic species but native hostplants and habitats are under great threat.

Acknowledgements

We thank Cynthia King (Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife) for collecting and forest access permits, Rhonda Loa (Hawaii Volcanoes National Park) and Pat Bily (The Nature Conservancy) for land access, permitting assistance, logistical and field support, Daniel Rubinoff (University of Hawai‘i at Mänoa) for conception of the project, and the participants and organizers of the leaf miner workshop conducted on Puna, HI in 2016. Klaus Sattler is thanked for extensive discussion about material in the NHMUK. We also thank Rory Frampton (West Maui Land Company) for help with access to Kauaula and Natalia Tangalin (National Tropical Botanical Garden), Steve Perlman (Hawaii Plant Extinction Prevention Program), Lono Dunn, Daniel Tanaka, Joe Ward, Pomaikai Kanaiaupio-Crozier (Puu Kukui Watershed Preserve), Hank Oppenheimer (Hawaii Plant Extinction Prevention Program), Chris Brosius (West Maui Mountain Watershed Partnership), and Keahi M. Bustamente (Leeward Haleakala Watershed Restoration Project) for their help coordinating fieldwork and collection. Chris Hamilton (Florida Museum of Natural History) provided useful feedback on the text. The project was funded by the National Science Foundation (Graduate Research Fellowship to CAJ; DEB #1354585 to AYK), the National Geographic Society (#C283-14 to CAJ; #9686-15 to AYK), the Entomological Society of America (2014 SysEB Travel Award to CAJ), the University of Florida’s Tropical Conservation and Development Program (2014 Field Research Grant to CAJ), the Florida Museum of Natural History (Lockhart Fellowship to CAJ), and an Society of Systematic Biologists SSB (2012 Mini-ARTS grant to AYK).

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