Phyllocnistis indistincta Kobayashi & Triberti

Kirichenko, Natalia, Triberti, Paolo, Kobayashi, Shigeki, Hirowatari, Toshiya, Doorenweerd, Camiel, Ohshima, Issei, Huang, Guo-Hua, Wang, Min, Magnoux, Emmanuelle & Lopez-Vaamonde, Carlos, 2018, Systematics of Phyllocnistis leaf-mining moths (Lepidoptera, Gracillariidae) feeding on dogwood (Cornus spp.) in Northeast Asia, with the description of three new species, ZooKeys 736, pp. 79-118 : 87-92

Phyllocnistis indistincta Kobayashi & Triberti sp. n. Figs 3, 4, 5, 6, 9 A–E, 11, 12, 13, 14, 16, 18

Etymology.

This Latin adjective, declined in the feminine gender, means “indistinct”. It is related to the longitudinal fascia in the forewing pattern that is basally indistinct in this species.

Diagnosis.

Forewing lustrous-white with a longitudinal white-yellow fascia and with an indistinct inner margin, three costal and four apical ciliary strigulae; male genitalia with phallus about as long as phallobase; female corpus bursae with two signa, similar in shape, the distal signa larger than the central signa.

Unlike other Cornus -feeding Phyllocnistis , the forewing pattern of P. indistincta has a well-defined outer margin of lf and an indistinct inner margin. Male genitalia differ from P. saepta by the phallus (about as long as phallobase or slightly shorter in P. indistincta ); female genitalia are only distinguishable from P. verae by the size and the shape of the two signa.

Type material.

Holotype (♂): Japan: Honshu, Menashi, Imai, Soni, Uda, Nara Prefecture, 34.52N, 136.11E, 630 m, ex Cornus controversa , 7.VI.2008 (larva), 16.VI.2008 em., SK853, S. Kobayashi leg. (deposited in OPU).

Paratypes.

149 (5♂, 19♀, 125 exs). All specimens were collected in Japan.

Host Cornus controversa : Honshu, 16 exs, Nasu-Kashidoro, Nasu Imperial Villa, Yumoto, Nasu, Tochigi Prefecture, 30.IX.2006, 1-10.X.2006 em., Rear. Nos 808-1-808-10, 809-1-809-5, K. Niimi leg.; 3 exs, same locality and data, 2.VIII.2007 col., 6-8.VIII.2007 em., 982-1-982-3; 1♂ 2♀ 2exs, Okuyamada, Takayama, Nagano Prefecture, 2.VIII.2010 (larva), 2-15.VIII.2010 em., MICRU068-16, MICRU067-16, SK323♂, TRB2020♂, S. Kobayashi leg.; 1♂ 3♀, Oshirakawa, Nagawa, Matumoto, Nagano Prefecture, 17.IX.2011 (larva), 29.IX.2011 em., S. Kobayashi leg. (deposited in OPU); 4 exs, Alps Park, Matsumoto, Nagano Prefecture, 9.X.2015 (larva), 24.X.2015 em., S. Yagi & T. Hirowatari leg. (deposited in ELKU); 1 ex, Fuji-Kawaguchiko, Yamanashi Prefecture, 3.VIII.2015 (larva), 11.VIII.2015 em., S. Kobayashi leg.; 1 ex, Kirara, Dando, Shidara, Aichi Prefecture, 30.IX.2008 (larva), 6.X.2008 em., S. Kobayashi & T. Hirowatari leg.; 2♀ 4 exs, Mt. Mikusa, Nose, Osaka Prefecture, 21.V.2008 (larva), 30.V.-8.VI.2008 em., SK154, 322; S. Kobayashi & T. Hirowatari leg.; [Soni, Uda, Nara Prefecture, S. Kobayashi leg.]: 1♀, Konagao, 24.V.2008 (larva), 27.V.2008 em., SK146; 1♂ 1♀ 4 exs, Konagao, 11-8.VI.2008 (larva); 17.VI.2008 em., 1 ex, Konagao, 12.X.2008 (larva), 23.X.2008 em.; 2 exs, Kumatawa, Konagao, 30.V.2015 (larva), 3.VI.2015 em.; 1♀, Imai, 12.VII.2008 (larva), 15.VII.2008 em., SK148; 1 ex, Imai, 12.X.2008 (larva), 19-20.X.2008 em.; Menashi: 1♂ 2 exs, 23.V.2008 (larva), 3 -10.VI.2008 em., SK320; 1♀ 2 exs, 7.VI.2008 (larva), 16.VI.2008 em., SK321; 1 ex, 14.VI.2008 (larva), 20.VI.2008 em.; 1 ex, 17.VI.2008 (larva), 21-24.VI.2008 em.; 1 ex, 5.VII.2008 (larva); 17.VII.2008 em.; 4 exs, 3-4.VII.2009 em., 27.VI.2009 (larva); 1 ex, 17.VI.2017 (pupa), 27.VI.2017 em. Shikoku, 1 ex, Fagus-no-mori, Kamagatani, Sawadani, Naka, Tokushima Prefecture, 24.VIII.2010 col., 27.VIII.2010 em., S. Kobayashi leg. Kyushu, Hikosan, Fukuoka Prefecture, 6 exs, 6-10.VII.1954; 7 exs, 15-26.VI.1955, H. Kuroko leg. 2 exs, Kirishima Spa., Kagoshima, 6.X.1964, H. Kuroko leg. (deposited in OPU).

Host C. florida : Honshu, [Menashi, Imai, Soni, Uda, Nara Prefecture, S. Kobayashi leg.]: 1♀, 7 exs, 26.VII.2008, 28.VII.-3.VIII.2008 em., SK164♀; 2♀ 17 exs, 27.VI.2009 (larva), 2-8.VII.2009 em., SK580 (vein); 1 ex, 19.VII.2010 (larva), 24-30.VII.2010; em.: 2 exs, Okukōchi-Sansō, Imai, 17.VI.2017 (pupa), 27.VI.2017 em., mine on upper side of bracts. Kyushu, Fukuoka, 1.VII.2016 (larva), 1.VII.2016 (1 adult, em. 11.VII.2016, rearing No. IsO-777) (deposited in OPU).

Host C. kousa : Honshu, 8 exs, Nasu-Kashidoro, Nasu Imperial Villa, Yumoto, Nasu, Tochigi Prefecture, 28.VII.2006 (cocoon), 5-8.VIII.2006 em., M. Murase leg.; 3 exs, 1.X.2008(larva), 7.X.2008em., Ohyoriai, Nagawa, Matsumoto, Nagano Prefecture, S. Kobayashi & T. Hirowatari leg.; Nara Prefecture: 2♀ 2 exs, Kawakami, 5.VIII.2011 (larva), 11-12.VIII.2011em., S. Kobayashi leg., slides TRB4151, TRB4153; 2exs, Tateriko, Nosegawa, 29.VII.2008 (larva), 4-18.VIII.2008 em., S. Kobayashi & T. Hirowatari leg.; Tottori Prefecture: 3exs, Mt. Daisen, 4.vii.1965, 9.VII.1965 em. (H. Kuroko), host: [Yamaboshi no Sōhō = (bracts)] (deposited in OPU).

Host C. macrophylla : Honshu, Nagano Prefecture, Matsumoto, N. Hirano leg.: 2 exs, Okada, 4-18.X.2004; 1 ex, Tomikusa, Anan, 30.VI.2006. 1♀, Tawamine, Konagao, Soni, Uda, Nara Prefecture, 24.V.2008 (larva), 27.V.2008 em. slide TRB4148, S. Kobayashi leg.; 2 exs, Same locality, 17.VII.2011 (larva), 20-25.VII.2011 em., S. Kobayashi leg.; 1 ex, Mt. Daisen, Tottori Prefecture, 4.VII.1965, 12.VII.1965, H. Kuroko leg. (deposited in OPU). Kyushu, 1♂, 2♀, Ito campus (Kyushu Univ.), Nishi-ku, Fukuoka, 26.V.2017 (larva), 31. V– 9.VI.2017 em., S. Yagi, T. Hirowatari, K. M. M. Kyaw & C. Tsuji leg. (deposited in ELKU).

Additional material examined.

Pupa (6): Honshu, 1 ex, Oshirakawa, Nagawa, Matsumoto, Nagano, Cornus controversa , 17.IX.2011 (larva), 29.IX.2011 (preserved), S. Kobayashi leg.; Soni, Uda, Nara Prefecture, S. Kobayashi leg., Cornus controversa : 1 ex, Konagao, 4.VI.2011 (larva), 17.VI.2011 (preserved); 4 exs, Menashi, Imai, 17.VI.2017 (larva), 19.VI.2017 (preserved), (deposited in OPU).

Larva (2): Honshu, 1 ex, Takayama, Gifu Prefecture, C. controversa , 6.X.2014, RMNH.INS.30395, E.J. van Nieukerken & S. Richter leg. (deposited in RMNH); Kyushu, 1 ex, Mt. Hikosan, Soeda, Fukuoka, Cornus kousa , 1.VII.2016, rearing No. IsO-764, I. Ohshima leg. (deposited in OPU).

Description of adult.

(Fig. 9 A–E). Wing span 5.0 mm in holotype, 4.0-6.5 mm in paratype; forewing length 2.4 mm in holotype, 2.0-3.0 mm in paratypes.

Head. Frons and vertex smooth, lustrous white. Antennae and labial palpi white yellowish.

Thorax. Tegulae, thorax and legs white. Forewing lustrous white, subapical area orange with a small apical black spot; a yellow-orange lf along costa from base to middle, margined with dark brown on both sides, then bent inwards distally, inner margin often indistinct in basal 2/3 not touching transverse fascia. Cilia white with a tf from costal 2/3 to dorsal 1/2, sometimes interrupted in the middle and three dark brown costal strigulae before apex; a black apical spot, giving origin to four divergent dark brown apical strigulae, one extending to upper part of costal cilia, the second and third to apex, the fourth to upper part of terminal cilia; terminal cilia white with a fuscous fringe line near termen. Hindwing lustrous white. This species and other members of the genus Phyllocnistis share an R1 vein arising from the apical half of the discoidal cell in the forewing (Fig. 13; Kawahara et al. 2017: Fig. 4C).

Abdomen. Mostly white yellowish dorsally, white ventrally. In the male, coremata present on segment 8, consisting of a pair of elongate, dilated extensions bearing a terminal cluster of long slender scales. In the female, dorsally on segment 8, a pair of tufts of scales longer than those covering the segment.

Male genitalia (Fig. 14). Tegumen elongate, touching apex of valvae, membranous, ventro-basally setose with 22 to 46 setae of varying length. Valva slender, broaded 1/4 to apex, transtilla arising from base of valva as an elongate, acute process (Fig. 14B, F); vinculum well developed, U-shaped; phallus slender, weakly sclerotised, externally finely wrinkled, about as long as phallobase or slightly shorter, cornuti absent (Fig. 14C, D).

Female genitalia (Fig. 16). Anterior apophyses slightly longer than posterior apophyses; ostium bursae opening in membrane between sternum 7 and 8; antrum membranous, funnel-shaped, narrowing slightly up to the size of the ductus bursae; ductus bursae completely membranous, slender, as long as antrum and terminating in the caudal area of corpus bursae; two signa are here present, usually similar in shape, the caudal bigger than central one, each with a single, short, median projection, but sometimes this projection, usually spine-shaped, is furcate or very reduced; on the wall around signa, minute scattered sclerites, thinner in the remainder of corpus bursae; ductus seminalis elongate, slightly larger than ductus bursae and arising from anterior end of corpus bursae; ductus spermathecae (not figured) with efferent canal short, forming 3 coils of equal diameter before vesicle.

Pupa.

(Fig. 18). Maximum length 2.8 mm, diameter 0.8 mm. Vertex with a triangular frontal process (cocoon-cutter), minutely serrated in profile and with elongated and thin apex curved towards dorsum (Fig. 18 A–F); a single pair of short setae at base of frons (clypeus) (Fig. 18A); antenna extending to abdominal segment A6. A pair of relatively long setae latero-dorsally on meso- and metathorax; forewing extending to A6-7. A pair of minute dorsal setae from A1 to A8 with a second pair of large thorn-like setae, more distal, from A3 to A8, delimiting an elongated area of minute spines, projected posteriorly, from A3 to A8 (Fig. 18 G–I); each abdominal segment with a pair of long, lateral, sensory setae, probably covered by the wings in A1; a pair of divergent lobate processes from caudal apex of A10 (Fig. 18 J–L).

Biology.

(Figs 3-6). The larvae mine leaves of Cornus species, forming a long serpentine mine parallel to leaf veins (Figs 3, 5 D–F and L); about 10 cm in length, 2.0-5.0 mm in width, with a brownish frass line 1.0 mm in width. There were one to two mines per leaf (Figs 3, 5D and J). The mines were usually observed on the lower side of leaf on C. controversa (Figs 3 A–D, 4 B–D), more often on upper side of leaf on C. florida and C. kousa (Fig. 5 D–F, J–L). Late instar larvae are about 4.0-6.0 mm long and pale yellow in colouration (Fig. 4H). The final instar spins a white cocoon at the leaf margin, the leaf margin slightly curled upwards by contraction of the cocoon silk. The pupal cocoon fold is 5.0 mm in length, 1.0-1.1 mm in width (Fig. 4I). Dr H. Kuroko collected adult moths of this species in Mt. Daisen, Tottori Prefecture, from flower bracts with mines containing larvae. In the present study, two bracts were observed of C. florida with similar serpentine mines (pale pink to ocherous, about 15 cm in length, 0.5-2.0 mm in width, brownish frass line: 0.1-0.2 mm in width) (Figs 3K, 6 C–E). A pupal cocoon fold (whitish to ocherous, 5.7 mm in length, 1.0 mm in width) was formed along the bract margin (Fig. 6F). A mine on the upper side of leaf was observed in the same tree (Fig. 6B).

In the Nasu Imperial Villa of Tochigi Prefecture, Arita et al. (2009) collected this species as Phyllocnistis sp. 1, “Mizuki-Kohamoguri” and noted some aspects of forewing pattern and leaf mine on Cornus controversa and C. kousa .

Phenology.

In Japan in 2008-2016, larvae were observed from June to October. The overwintering form of this species is unknown.

Ecology and host plants.

(Fig. 5A, B). The host plants are Cornus controversa , C. florida , C. macrophylla and C. kousa .

Distribution.

Japan: Honshu (Tochigi, Nagano, Yamanashi, Aichi, Nara, Osaka and Tottori Prefectures), Shikoku (Tokushima Prefecture), Kyushu (Fukuoka and Kagoshima Prefectures).

Remarks.

In the type series of P. indistincta , some specimens have a forewing pattern which differs in the following points: 1) a well-defined inner margin of lf (Figs 11C, F, 12C, E–G, K), 2) a fuscous to dark orange dorsal spot at dorsum 1/4 (Figs 11C, F, 12F), 3) tf is indistinct or interrupted in the middle (Figs 11C, 12B, C, G and I), i.e. more similar to that of the other Cornus -feeding Phyllocnistis . The forewing pattern differences were recorded in the type locality of this species, Menashi, Nara Prefecture (Figs 11D, E, 12 A–C), in Ohshirakawa, Nagano Prefecture (Figs 11C, F, 12E) and in Nasu Imperial Villa, Tochigi Prefecture (Fig. 12F; see also Arita et al. 2009: Pl. 3, Fig. 17). Judging from the genital characters, the differences in forewing pattern are treated as individual variation. The Indian and Japanese species, P. toparcha has a similar forewing pattern, with individual variation as P. indistincta , but P. toparcha is separated from P. indistincta by well-defined inner margin of strigulae and rather large lf. Accoding to Kuroko (1982), the autumn generation of P. toparcha has bolder strigulae and scattering fuscous to dark scales from base to dorsum 1/2 than the summer generation, but SK collected adult moths of P. toparcha having a dark dorsal spot or blotch and a darker patch in the lower half of the apical portion in summer (Kobayashi, unpublished data).