Head: Head yellow, frons often with pruinosity. Orbital plates more or less emerge from the plane of frons. Front orbitals three pairs; one ori directed inward and two ors directed up. 1–2(3) pairs of medio-clinate lower orbital setae, two pairs of reclinate upper orbital setae. Orbital setulae proclinate, upright or partly reclinate. Postocellar and ocellar setae well developed. First flagellomere round.

Thorax : Scutum with 1+3 dorsocentrals. Acrostichal setulae in two rows, but lacking in some species. Postpronotal, two propleural, presutural, and propleural setae normal or strong. Anepisternum with a long posterior seta and with two or three shorter posterior setae. Katepisternum with one or two long setae. Legs simple, only ventroapical seta on middle tibia present. Costal vein ends at apex of M₁. The ratio of ultimate and penultimate sections of M₄ various.

Abdomen : Male abdomen lacks stridulatory organs.

Male genitalia : Epandrium round apically, often with a comb of several fused tubercle-like setae and/or elongated tubercle-like setae on the inner surface; surstylus setigerous and sometimes with one or a few tubercle-like setae. Subepandrial sclerite short but very broad, connecting bases of surstyli through a special sclerite. Hypandrium very long but very thin. Hypophallus membranous often with a pair of parallel sclerites medially. Paraphallus present or absent. Mesophallus cylindrical and well sclerotized. Distiphallus with basal part formed by usually a paired sclerite and an apical part, which terminates in paired tubes or in extremely long less sclerotized tubules. Ejaculatory apodeme variable, but basal part usually broad and blade not too large.

Female postabdomen : Tergite 10 trifurcate or cruciform posteriorly. Cercus with two stout, apical, trichoid sensilla.

Japan: 1♂1♀ (MK-AG-a410, a26), Namari-kawa, Yakumo, Futami, Hokkaido (42.201151°N, 140.135658°E, 145 m asl), 10-VI-2012 (as larva), emerged on 13–17-VI-2012, NMNS.

A medium-sized yellow species (wing length 1.7–1.8 mm) that has a pruinose yellow scutum with one medial and two pairs of gray lateral stripes, black 1^st flagellomeres, yellow maxillary palpi, yellow halteres, and yellow legs. Male epandrium inner-laterally with a comb consisting of six fused long tubercle-like setae, and surstylus with two tubercle-like setae. Larva mines the thallus of Marchantia polymorpha L.

Adult male (Fig. 1A–E).

Head : Head light yellow, with ocellar tubercle brown, back of head dark brown (Fig. 1A). Lunule distinct and slightly sunken. Antenna porrect, first flagellomere black, pedicel and scape yellow. Arista subbasal, black pubescent. Eye upright, bare. Face slightly convex. Gena straight. Clypeus, face, and postgena yellow. Proboscis normal, yellow; palpus yellow, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 1B). Orbital setulae minute and erect, in a single row.

Figure 1. 

Phytoliriomyza dorsata A–E male at Yakumo A habitus B lateral body C frontal head D dorsal thorax E thorax in posterior view F, G female at Yakumo F dorsal thorax G lateral body H–J male genitalia H whole genitalia, ventral I phallic complex, ventral J epandrium, ventral K, L female postabdomen K oviscape and spermatheca L tergite 10 M–O mined thalli of Marchantia polymorpha M mined thallus dissected to show interior and puparium (arrow) N mined thallus with exit hole O the same thallus with the mine dissected to show a puparium (arrow).

Thorax : Thorax pruinose. Scutum yellow with medial dark stripe on anterior 2/3, with a pair of wide dark intra-alar stripes and a pair of narrower dark supra-alar stripes, adjoining a pair of lateral presutural dark ovoid spots (Fig. 1D). Scutellum yellow with lateral corner brown. Subscutellum with anterior half yellow, ventral half brown. Mediotergite brown, anatergite and katatergite yellow. Pleuron largely yellow, venters of katepisternum and meron brown. Haltere yellow. Calypter margin and hairs gray. Leg segments yellow; tibiae and tarsi darker. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened in length anteriorly (Fig. 1D). Acrostichal setulae eight or nine pairs in two rows. Wing: Wing length 1.7 mm, costa reaching M₁ (Fig. 1A). Length of ultimate section of vein M₄ divided by penultimate section 1.7.

Abdomen : Abdomen dorsally subshiny yellow; epandrium dark brown (Fig. 1B). Genitalia: (Fig. 1H–J) Epandrium rounded apically, with a short tubercle-like seta on inner-middle surface, a comb comprising six long fused tubercle-like setae on inner-anterior surface, a few short tubercle-like setae immediately outward of the comb; and a row of minute tubercle-like setae on ventral inner margin (Fig. 1J). Surstylus rounded, setose apically, with two short tubercle-like setae posteriorly. Cercus narrow, setose. Subepandrial sclerite with one pair of medial flat, plate-like ventral processes and hook-shaped protrusion directing anteriorly (Fig. 1J). Hypandrium slightly sclerotized along outer margin (Fig. 1H). Postgonite bare and broadly rounded apically (Fig. 1I). Phallophorus with deep incision below, articulated with phallapodeme, fused to epiphallus (Fig. 1I). Basiphallus with a narrow plate on left side (Fig. 1I). Hypophallus membranous with a pair of small, parallel sclerites medially (Fig. 1I). Paraphallus broad membranous, with pointed, lightly sclerotized margins; paraphalli diverging, angled anteroventrally, jointed basally (Fig. 1H). Mesophallus dark, cylindrical, widest subbasally, length similar to that of distiphallus. Distiphallus comprising one pair of stout tubules; basal half composed of dorsal bulbous dark sclerites and weaker medial region; distal half cylindrical, dorsally and laterally pigmented (Fig. 1H).

Female (Fig. 1F, G). Similar to male, but slightly larger and frons wider. Wing length 1.8 mm. Postabdomen: (Fig. 1K, L) Oviscape dark brown, setigerous (Fig. 1K). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 1L). Sternite bearing four pairs of marginal setae. Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus (Fig. 1L). Spermathecae orbicular (Fig. 1K).

Usuobi-zenigoke-hamoguribae.

Marchantia polymorpha (Marchantiaceae).

(Fig. 1M–O) Larvae construct linear mines in the thallus of liverwort in early instars, later entering the midrib, and pupating there, while mines are obscure from outside.

The host plants from which this species emerged grow on wet cliffs along roads in a cool temperate forest of Quercus crispula.

Thus far, recorded from Europe, North America, and Japan. The authors recorded only from southern Hokkaido (Fig. 2).

Figure 2. 

Locality records of three Phytoliriomyza species associated with Marchantia spp.: P. dorsata, P. igniculus, P. tsukuyomi, P. marchantiae and P. nubatama.

The morphology of the Japanese specimens closely coincided with the description of P. dorsata by Spencer (1976), but not with the description by Papp and Černý (2017), particularly concerning the morphology of the epandrium and distiphallus, which suggests the presence of multiple related species in Europe. Related Phytoliriomyza species (P. bornholmensis and P. islandica) were described by Spencer (1976) and Ólafsson (1988), but they were synonymized with P. dorsata by Zlobin (2005). The taxonomic confusion would be caused by scarcity of specimens of these rare species and lack of information on their biology. Our numerous reared specimens and extensive records of host plants suggest that bryophyte-associated Phytoliriomyza species are diverse, and that the synonymized species may be definite species circumscribed by external and genital morphology.

This species resembles P. brunofasciata in having two pairs of dark lateral stripes on the scutum, but it is distinguished from P. brunofasciata by the dark-sided scutellum (scutellum wholly yellow in P. brunofasciata) and the number of tubercle-like setae on the surstylus of the male epandrium (two in P. dorsata; one in P. brunofasciata).

Holotype: Japan: 1♂ (MK-AG-a323), Matsubara-ko, Koumi, Nagano Pref. (36.053896°N, 138.461847°E, 1110 m), 18-IV-2021 (as larva), emerged on 17-V-2021, NSMT-I-Dip 31890. Paratypes: Japan: 1♂1♀ (MK-AG-a454, a453), same data as holotype, emerged on 17-V-2021, NSMT-I-Dip 31891, 31892; 1♀ (MK-AG-a324), Iwaobetsu, Shari, Hokkaido, 1-V-2021 (as larva), emerged on 28-V-2021, NSMT-I-Dip 31893; 1♀ (MK-AG-a325), Odarumi, Makioka, Yamanashi Pref., 30-VI-2021 (as larva), emerged on 4-VII-2021, NSMT-I-Dip 31894; 1♀ (MK-AG-a326), Ikawa-toge, Aoi-ku, Shisuoka Pref., 26-V-2021 (as larva), emerged on 9-VI-2021, NSMT-I-Dip 31895; 1♀ (MK-AG-a28), Shirabiso-toge, Kamimura, Iida, Nagano Pref., 27-IV-2014 (as larva), emerged on 22-V-2014, NSMT-I-Dip 31896.

Japan: 35♂37♀, same data as holotype, emerged on 8–17-V-2021; 9♂5♀, Iwaobetsu, Shari, Hokkaido, 1-V-2021 (as larva), emerged on 26–28-V-2021; 3♂1♀, Horoman-kyo, Samani, Hokkaido, 30-IV-2021 (as larva), emerged on 26–31-V-2021; 1♂2♀, Odarumi, Makioka, Yamanashi Pref., 27-VI-2014 (as larva), emerged on 15-VII-2021; 1♂1♀, Shirabiso-toge, Kamimura, Iida, Nagano Pref., 27-IV-2021 (as larva), emerged on 23–25-V-2021; 22♂20♀, Ikawa-toge, Aoi-ku, Shisuoka Pref., 26-V-2021 (as larva), emerged on 8–17-VI-2021.

A large yellow species (wing length 2.0–2.1 mm) having a pruinose dark gray scutum with a trapezoid yellow patch medially on posterior 1/3, a yellow scutellum, black 1^st flagellomeres, yellow maxillary palpi, yellow halteres, and yellow legs. Male epandrium with a comb comprising five or six fused long tubercle-like setae. Larva mines the thallus of Marchantia polymorpha.

Adult male (Fig. 3A–E).

Head : Head light yellow, with ocellar tubercle dark brown, frons yellowish brown, back of head dark brown excluding margins (Fig. 3C). Antenna porrect, first flagellomere black, pedicel and scape yellow. Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus yellow, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 3B). Orbital setulae minute and erect, in a single row.

Figure 3. 

Phytoliriomyza igniculus sp. nov. A–E holotype male A habitus B lateral body C frontal head and ventral body D dorsal thorax E thorax in posterior view F–H male genitalia F whole genitalia G phallic complex H postgonite I epandrium J a living female fly on a thallus of Marchantia polymorpha K, L female postabdomen K oviscape and spermatheca L tergite 10.

Thorax : Thorax pruinose. Scutum dark gray with a trapezoid pale yellow patch medially on posterior 1/3 (Fig. 3D). Scutellum pale yellow. Subscutellum with anterior half yellow, ventral half brown. Mediotergite brown, anatergite and katatergite yellow (Fig. 3B). Pleuron yellow; propleuron with small brownish spots on venter; anepisternum with three brown spots on anterior and middle dorsal margins and middle venter; several small brown spots on anepimeron, katepisternum and meron with brow patches on venter (Fig. 3B). Haltere yellow. Calypter margin and hairs gray (Fig. 3B). Leg segments yellow; tibia and tarsus darker (Fig. 3A). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 3D). Acrostichal setulae six or seven pairs in two rows. Wing: Wing length 2.1 mm, costa reaching M₁ (Fig. 3A). Length of ultimate section of vein M₄ divided by penultimate section 1.3–1.7.

Abdomen : Abdomen dorsally subshiny yellow, with a pair of brown lateral semicircular patches on anterior half of the 2^nd tergite; epandrium dark brown (Fig. 3E). Genitalia: (Fig. 3F–I). Epandrium rounded apically, with a long tubercle-like seta on subposterior inner-lateral surface; inner-anterior surface with a comb comprising five or six fused long tubercle-like setae (Fig. 3I). Surstylus hood-like, curved inward, setose apically, with single long tubercle-like seta on outer distal margin. Cercus narrow, setose, with a strong seta apically (Fig. 3I). Subepandrial sclerite with one pair of flat, pale, blade-like ventral process and one pair of setae outward (Fig. 3I). Hypandrium slightly sclerotized along outer margin (Fig. 3F). Postgonite bare and broadly rounded apically (Fig. 3H). Phallophorus with deep incision below, articulated with phallapodeme, fused to epiphallus (Fig. 3F, G). Basiphallus with a narrow plate on left side; length similar to that of mesophallus (Fig. 3G). Hypophallus broad, membranous, medially with a pair of fused linear sclerites; distal half diverging (Fig. 3G). Paraphallus absent. Mesophallus dark, cylindrical, widest subbasally, slightly shorter than distiphallus (Fig. 3G). Distiphallus comprising one pair of stout tubules; basal half composed of ventral dark bulbous sclerite and weaker medial region curving outward; distal half cylindrical and well-pigmented, with truncated, unpigmented apex (Fig. 3G). Ejaculatory apodeme fan-shaped, blade pale with clear margin, with narrow stalk, broad base, and clear sperm pump.

Female. Similar to male, but slightly larger and frons wider. Wing length 2.1 mm. Postabdomen: (Fig. 3K, L) Oviscape dark brown, setigerous. Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 3K). Each cercus with two stout, apical, trichoid sensilla, 1/3 length (Fig. 3L). Spermathecae orbicular (Fig. 3K).

The specific name (igniculus = small fire) refers to the yellow oblong patch on the scutum.

Kitsunebi-zenigoke-hamoguribae.

Marchantia polymorpha (Marchantiaceae).

Larvae construct linear-botch mines in the thallus, particularly in the midrib, and pupate in the mines (Fig. 4C–E).

Figure 4. 

Habitat of Phytoliriomyza igniculus sp. nov. and its host plant, Marchantia polymorpha A habitat at levee of a rice field at type locality B thalli with male receptacles C mined thallus containing an internal puparium (arrow) D the same thallus in transmitted light (arrows indicating mines) E mined thallus at Ikawa-toge.

The host plants from which this species emerged, grow on mesic soils along roads in cool temperate forests (beech forests dominated by Fagus crenata in Honshu and deciduous oak forests dominated by Quercus crispula in Hokkaido) and on levees of paddy fields in a cool temperate forest ecosystem (Fig. 4A, B). Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Japan: Hokkaido and Honshu (Fig. 2).

This species is distinguished from all other species of Phytoliriomyza with black-banded yellow thorax by the unique brown patches on the 2^nd abdominal tergite (absent in other species). This species resembles P. izayoi, P. chichibuensis and P. caliginosa in the yellow pattern of the scutum and scutellum; it is distinguished from them by the wholly yellow scutellum without dark lateral corners and by the number of tubercle-like setae of the comb on the male epandrium (P. igniculus, 5–6; P. izayoi, 6–8; P. caliginosa, 8–11). This species also resembles P. cometiformis and P. luna in having a yellow scutellum; it is distinguished from them by the number of tubercle-like setae of the comb on the male epandrium (P. igniculus, 5–6; P. cometiformis, 3; P. luna, 7–8). This species also resembles P. islandica in the yellow pattern of the scutellum; it is distinguished by the black first flagellomere (brown in P. islandica).

Holotype: Japan: 1♂ (MK-AG-a397), Matsubara-ko, Koumi, Nagano Pref. (36.053896°N, 138.461847°E, 1110 m asl), 12-V-2021 (as larva), emerged on 18-VI-2021, NSMT-I-Dip 31897. Paratypes: Japan: 1♂1♀ (MK-AG-a455, a443), same data as holotype, emerged on 17–22-VI-2021, NSMT-I-Dip 31898, 31899; 1♂1♀ (MK-AG-a521, a528), Ikawa-toge, Aoi-ku, Shisuoka Pref., 26-V-2021 (as larva), emerged on 31-V–2-VI-2021, NSMT-I-Dip 31900, 31901; 1♂ (MK-AG-a577), Tokuzo-ji, Yana, Kisarazu, Chiba Pref., 1-XI-2021 (as larva), emerged on 3-XII-2021, NSMT-I-Dip 31902.

Japan: 1♂1♀, Ikawa-toge, Aoi-ku, Shizuoka Pref., 26-V-2021 (as larva), emerged on 31-V–2-VI-2021; 1♂, Tokuzo-ji, Yana, Kisarazu, Chiba Pref., I-XI-2021 (as larva), emerged on 3-XII-2021.

A medium-sized species (wing length 1.6–1.7 mm) having pruinose dark gray scutum, light yellow scutellum, black 1^st flagellomere, dark maxillary palpus, dark halteres, and dark legs. Male epandrium inner-basally with a comb of four unfused tubercle-like setae, and inner-laterally with a comb of three or four fused, long, tubercle-like setae; surstylus bilobed and hypertrophied dorsal arm with one tubercle-like seta. Larva mines the thallus of Marchantia polymorpha.

Adult male (Fig. 5A–E).

Head : Head light yellow, with ocellar tubercle brown, frons light yellow, back of head dark brown (Fig. 5C). Antenna porrect, first flagellomere black, pedicel and scape light yellow. Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus brownish gray, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 5D). Orbital setulae minute and erect, in a single row.

Figure 5. 

Phytoliriomyza tsukuyomi sp. nov. A–E holotype male A habitus, B lateral C frontal D dorsal E posterior F paratype female (MK-AG-a442) G–J male genitalia G whole genitalia, ventral H phallus complex, lateral I epandrium J ejaculatory apodeme, lateral K, L female postabdomen K oviscape and spermatheca L tergite 10 M mined thallus of Marchantia polymorpha.

Thorax : Thorax pruinose. Scutum pruinose bluish gray with a medial black band and a pair of lateral black bands (Fig. 5D). Scutellum pale yellow with lateral corner dark brown. Subscutellum dark brown with anterior margin pale yellow. Mediotergite, anatergite, and katatergite brown. Pleuron largely yellow; postpronotal lobe with anterior brown spot; notopleuron with brown spot on venter; anepisternum and anepimeron with brown venters; katepisternum an meron with dark brown patches on venter (Fig. 5B). Haltere gray, with grayish yellow stalk. Calypter margin and hairs gray. Leg segments brownish gray; tarsus darker. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 5D). Acrostichal setulae six or seven pairs in two rows. Wing: Wing length 1.7 mm, costa reaching M₁ (Fig. 5A). Length of ultimate section of vein M₄ divided by penultimate section 1.9.

Abdomen : Abdomen dorsally subshiny brown; epandrium dark brown (Fig. 5E). Genitalia: (Fig. 5G–J) Epandrium rounded apically; inner-lateral margin with a large round arm having three or four unfused tubercle-like setae apically; inner-anterior surface with a large arm having a hand-shaped comb comprising four basally fused long tubercle-like setae apically, and one tubercle-like seta immediately inward from the protrusion (Fig. 5I). Surstylus lobate, setose apically; inner-basally with a long, S-curved, hypertrophied, columnar arm, bearing one long tubercle-like seta apically (Fig. 5I). Cercus narrow, setose, with a strong seta apically (Fig. 5I). Subepandrial sclerite consisting of one pair of lateral plates (one seta each subapically on inner surface) forming (Fig. 5I). Hypandrium slightly sclerotized along outer margin (Fig. 5G). Postgonite bare, goose barnacle-shaped and cleft apically; upper lobe pointed apically (Fig. 5H). Phallophorus with deep incision below (Fig. 5G), articulated with phallapodeme, fused to epiphallus (Fig. 5H). Basiphallus with a narrow plate on left side; dorsally lightly sclerotized; shorter than mesophallus. Hypophallus broad, membranous, ventral side covered with microtrichia, medially with a pair of short fused linear sclerites (Fig. 5G, H). Paraphalli lobe-like, membranous; posterior margin slightly sclerotized (Fig. 5G, H). Mesophallus dark, cylindrical, widest subbasally, slightly longer than distiphallus (Fig. 5H). Distiphallus comprising one pair of stout tubules; basal half composed of ventral dark triangular sclerite and weaker medial region; distal half cylindrical, dorsally pigmented, with truncated, unpigmented apex (Fig. 5H). Ejaculatory apodeme fan-shaped, blade pale with clear margin, with sclerotized stalk, broad asymmetric base, and clear sperm pump (Fig. 5J).

Female (Fig. 5F–I). Similar to male, but slightly larger and frons narrower (Fig. 5F). Wing length 1.7 mm. Postabdomen: (Fig. 5K, L) Oviscape dark brown, setigerous (Fig. 5K). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 5L). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus. Spermathecae orbicular (Fig. 5K).

The specific name tsukuyomi is a Japanese word meaning brightness of moonlight, and refers to the bright yellow scutellum.

Tsukuyomi-zenigoke-hamoguribae.

Marchantia polymorpha (Marchantiaceae).

Larvae mine the thallus of the host plant and pupate in the mines. The mines are not apparent from the outside.

The host plants from which this species emerged, grow on mesic soils on levee of paddy fields and along roads in natural beech forests (Fig. 5T). Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Japan: Honshu (Fig. 2).

This species resembles P. alpicola in color pattern of the scutum (entirely dark mesothorax and uniformly pale scutellum); it is distinguished from the latter by the yellow pedicel and scape of the antenna (pedicel and scape of P. alpicola are brown), yellow maxillary palpus (dark gray in P. alpicola), and number and arrangement of tubercle-like setae in a comb on the male epandrium (4 hand-shaped in P. tsukuyomi; 6 fused in P. alpicola).

Holotype: Japan: 1♂ (MK-AG-a320), Namari-kawa, Yakumo, Futami, Hokkaido (42.187765°N, 140.122182°E, 190 m asl), 2-VI-2021 (as larva on Marchantia paleacea paleacea), emerged on 17-VI-2021, NSMT-I-Dip 31903. Paratypes: Japan: 1♂2♀ (MK-AG-a484, a485, a442), same data as holotype, emerged on 18-VI–3-VII-2021, NSMT-I-Dip 31904–31906; 1♂ (MK-AG-a322), Renge-onsen, Itoigawa, Niigata Pref., 11-VII-2021 (as larva on M. p. paleacea), emerged on 5-VIII-2021, NSMT-I-Dip 31907; 1♂ (MK-AG-a321), Nippara, Okutama, Tokyo Pref., 27-III-2021 (as larva on M. p. paleacea), emerged on 27-V-2021, NSMT-I-Dip 31908; 1♀ (MK-AG-302), Umegashima, Aoi-ku, Shizuoka Pref., 5-I-2014 (as larva on M. p. diptera), emerged on ?-V-2014, NSMT-I-Dip 31909; 1♂ (MK-AG-a356), Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 20-III-2000 (as larva on M. p. diptera), emerged on 17-IV-2000, NSMT-I-Dip 31910; 1♂ (MK-AG-a355), Muramatsu, Iwakura, Sakyo-ku, Kyoto Pref., 11-VI-2021 (as larva on M. polymorpha), emerged on 21-VII-2021, NSMT-I-Dip 31911; 1♂ (MK-AG-a358), Naiku, Oe, Fukuchiyama, Kyoto Pref., 19-V-2021 (as larva on M. papillata grossibarba), emerged on 3-VII-2021, NSMT-I-Dip 31912.

Japan: On Marchantia paleacea paleacea: 22♂16♀, Namari-kawa, Yakumo, Futami, Hokkaido, 2-VI-2021 (as larva), emerged on 9-VI–7-VII-2021; 38♂44♀, Renge-onsen, Itoigawa, Niigata Pref., I-VII-2021 (as larva), emerged on 29-VII–9-VIII-2021; 2♂1♀, Narahara, Ueno, Tano, Gunnma Pref., 18-IV-2021 (as larva), emerged on 30–31-V-2021; 2♂4♀, Kanna-gawa, Nakatsugawa, Chichibu, Saitama Pref., 14-XI-2010 (as larva), emerged on 26-IV-2010; 2♂1♀, Nippara, Okutama, Tokyo Pref., 27-III-2021 (as larva), emerged on 27-IV–21-V-2021; 5♂5♀, Yashajin-toge, Minami-arupusu, Yamanashi Pref., 25-III-2021 (as larva), emerged on 2-V–1-VI-2021.

On Marchantia paleacea diptera: 2♂3♀, Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 26-V-2021 (as larva), emerged on 17–27-VI-2021; 1♂5♀, Abe-toge, Aoi-ku, Shizuoka Pref., 30-XI-2014 (as larva), emerged on 30-IV–8-V-2014; 3♂5♀, Kuchisakamoto, Aoi-ku, Shizuoka Pref., 26-V-2021 (as larva), emerged on 1–26-VI-2021; 6♂8♀, Tsudono, Aoi-ku, Shizuoka Pref., 30-XI-2014 (as larva), emerged on 30-IV–6-V-2014; 2♂4♀, Tosayama, Kochi, Kochi Pref., 27-II-2011 (as larva), emerged on 23–28-IV-2011; 1♂3♀, Mt. Nabejiri, Taga, Shiga Pref., 4-V-2021 (as larva), emerged on 27-V–15-VI-2021; 6♂3♀, Naiku, Oe, Fukuchiyama, Kyoto Pref., 19-V-2021 (as larva), emerged on 2–10-VII-2021; 2♂3♀, Iya-kei, Ikeda, Miyoshi, Tokushima Pref., 1-II-2014 (as larva), emerged on 4–4-V-2014; 2♂5♀, Okujisso, Isa, Kagoshima Pref., 17-XII-2017 (as larva), emerged on 22–30-III-2012.

On Marchantia polymorpha: 1♀, Matsubara-ko, Koumi, Nagano Pref., 18-IV-2021 (as larva), emerged on 18-VI-2021; 7♂2♀, Odarumi, Makioka, Yamanashi Pref., 30-VI-2021 (as larva), emerged on 28-VII–4-VII-2021; 5♂15♀, Muramatsu, Iwakura, Sakyo-ku, Kyoto Pref., 31-XII-2013 (as larva), emerged on ?-V-2013.

On Marchantia papillata grossibarba: 2♂1♀, Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 26-V-2021 (as larva), emerged on 18-VII-2021; 3♂5♀, Naiku, Oe, Fukuchiyama, Kyoto Pref., 19-V-2021 (as larva), emerged on 2–10-VII-2021; 2♂1♀, Seikandoro, Kumanogawa, Shingu, Wakayama Pref., 7-VII-2021 (as larva), emerged on 27-VII–4-VIII-2021; 1♀, Nagabuchi, Ume, Saeki, Oita Pref., 29-XI-2011 (as larva), emerged on 3-V-2011.

A medium-sized species (wing length 1.6–1.8 mm) having dark gray scutum, dark-cornered yellow scutellum, black 1^st flagellomere, black maxillary palpus, gray halteres, and brown legs. Male epandrium with a comb comprising seven or eight fused long tubercle-like setae. Larva mines the thallus of Marchantia spp.

Adult male (Fig. 6A–E).

Head : Head light yellow, with ocellar tubercle brown, frons light yellow, back of head dark brown (Fig. 6C). Antenna porrect, first flagellomere black, pedicel and scape brown. Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus brown, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 6B). Orbital setulae minute and erect, in a single row.

Figure 6. 

Phytoliriomyza marchantiae sp. nov. A–E holotype male A habitus B lateral C frontal D dorsal E posterior F paratype female (MK-AG-a442), dorsal G–I male genitalia G–I emerged from Marchantia paleacea paleacea at type locality J–M emerged from M. papillata grossibarba at Mt. Oe. G whole genitalia, ventral H phallus complex, lateral I, L epandrium, ventral J, K phallic complex, ventral and lateral M ejaculatory apodeme, lateral.

Thorax : Thorax pruinose. Scutum pruinose gray, with a dark gray medial stripe on anterior 2/3, one pair of dark gray lateral stripes, and with narrow yellow patch along posterior margin (Fig. 6D). Scutellum light yellow with lateral corners widely brownish. Subscutellum brown with anterior margin light yellow. Mediotergite, anatergite and katatergite dark brown. Pleuron largely yellow; postpronotal lobe with anterior brown spot; notopleuron with brown narrow spot along anterior lower margin; anepisternum and anepimeron with brown venters; katepisternum and meron with dark brown patches on venter (Fig. 6B). Haltere yellowish gray, with yellow stalk. Calypter margin and hairs gray. Leg segments brown; tibia and tarsus darker (Fig. 6A). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 6D). Acrostichal setulae five or six pairs largely in two rows. Wing: Wing length 1.6–1.7 mm, costa reaching M₁ (Fig. 6A). Length of ultimate section of vein M₄ divided by penultimate section 1.6–1.8.

Abdomen : Abdomen dorsally subshiny brown (Fig. 6E). Genitalia: (Fig. 6G–M) Epandrium dark brown, rounded apically, inner-lateral surface medially with one tubercle-like setae; inner-anterior surface ventrally with a comb comprising eight fused long tubercle-like setae; ventral margin with a row of several minute tubercle-like setae (Fig. 6I, L). Surstylus subrectangular, setose apically. Cercus narrow, setose. Subepandrial sclerite with one pair of spines and one pair of plate-like ventral processes; tips hook-like (Fig. 6I). Hypandrium slightly sclerotized along outer margin. Postgonite bare and goose barnacle-shaped (Fig. 6H). Phallophorus with shallow incision below (Fig. 6J), articulated with phallapodeme, fused to epiphallus (Fig. 6H, K). Basiphallus with subtriangular dorsal sclerite; 2/3 × as long as mesophallus (Fig. 6H, K). Hypophallus subtriangular membranous, lined with numerous microtrichia ventrally, medially with a pair of fused linear pale sclerites (Fig. 6H, K). Paraphalli consisting of a pair of incurved narrow pigmented sclerites and a pair of triangular plate-like pigmented sclerites (Fig. 6H, K). Mesophallus dark, cylindrical, widest subbasally, slightly longer than distiphallus (Fig. 6H). Distiphallus comprising one pair of stout tubules; basal half composed of ventral dark scalpel-shaped sclerite and weaker medial region; distal half cylindrical, dorsally and laterally pigmented, with truncated, unpigmented apex (Fig. 6H, K). Ejaculatory apodeme fan-shaped, blade pale with apical half clear; sclerite of sperm pump with lateral extension; sperm pump clear (Fig. 6M).

Female (Fig. 6I–K). Similar to male, but scutellum darker than male (Fig. 6F). Wing length 1.6 mm. Postabdomen: (Fig. 7A, B) Oviscape dark brown, setigerous (Fig. 7A). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 7B). Cercus with two stout, apical, trichoid sensilla, ½ length of cercus. Spermathecae semi-orbicular (Fig. 7A).

Figure 7. 

Female morphology and larval ecology of Phytoliriomyza marchantiae sp. nov. A, B female postabdomen (at Renge-onsen) A oviscape and spermatheca B tergite 10 C–E habitat and mined thalli on Marchantia paleacea paleacea C habitat at type locality D, E mined thalli at Yashajin-toge and Renge-onsen F–H habitat and mined thalli on M. p. diptera F habitat at Kuchisakamoto G, H mined thalli at Iwaya-kei and Tosayama. Arrows indicate internal puparia.

The yellow patch on posterior scutum slightly varied from distinct to obscure ones among localities but not among host liverwort species/subspecies (Fig, 6F–K).

The specific name refers to host plant genus, Marchantia.

Uzumibi-zenigoke-hamoguribae.

The main host plants are Marchantia paleacea paleacea and M. p. diptera (Marchantiaceae), with M. polymorpha and M. papillata grossibarba also recorded as host in some localities.

Larvae construct linear mines in the thallus, particularly in the midrib, and pupate in the mined thalli (Fig. 7D, E, G, H).

Marchantia paleacea paleacea grows on rocky substrates of cliffs, slopes and riverbanks in cool temperate deciduous forests (Fig. 7C) and Marchantia p. diptera in warm temperate evergreen forests (Fig. 7F). While these subspecies are frequently utilized by P. marchantiae, they are never utilized by the other three Marchantia-associated species, P. igniculus, P. tsukuyomi, and P. nubatama. P. marchantiae is also recorded from M. polymorpha in cool temperate forests and M. papillata grossibarba in warm temperate evergreen forests in some localities. Our rearing records suggest that this species is multivoltine.

Japan: Hokkaido, Honshu, Shikoku, Kyushu (Fig. 2).

This species resembles P. rebouliae, P. lanternaria, and P. conocephali in the narrow yellow posterior margin of the scutum and medial yellow stripe of the scutellum; it is distinguished from P. rebouliae by number of tubercle-like setae in a comb of the male epandrium (8 in P. marchantiae; 7 in P. rebouliae), from P. lanternaria and P. conocephali by the number of tubercle-like setae on the surstylus of the male epandrium (0 in P. marchantiae; 1–2 in P. lanternaria and P. conocephali).

This species also resembles Phytoliriomyza miki (Strobl, 1898) in color pattern of the scutum and morphology of the male genitalia; it is distinguished from the latter by the number of tubercle-like setae in a comb on the male epandrium (8 in P. marchantiae; 5 in P. miki).

Holotype: Japan: 1♂ (MK-AG-a413), Mt. Mihara, Hachijo Is. Tokyo Pref. (33.11383°N, 139.82415°E, 170m), 17-II-2012 (as larva on Marchantia emarginata cuneiloba), emerged on 23-IV-2012, NSMT-I-Dip 31913. Paratypes: Japan: 1♀ (MK-AG-323), same data as holotype, NSMT-I-Dip 31914; 1♀ (MK-AG-a379), Naiku, Oe, Fukuchiyama, Kyoto Pref., 19-V-2021 (as larva on M. papillata grossibarba), emerged on 9-VI-2021, NMNS; 1♀ (MK-AG-a383), Tsudono, Aoi-ku, Shizuoka Pref., 19-V-2021 (as larva on M. papillata grossibarba), emerged on 10-V-2014, NSMT-I-Dip 31916; 1♂1♀ (MK-AG-a456, a359), Mt. Osuzu, Tsuno, Miyazaki Pref., 11-IV-2021 (as larva on M. papillata grossibarba), emerged on 21–22-V-2021, NSMT-I-Dip 31917, 31918; 1♀ (MK-AG-344), Jizodo, Mariya, Kisarazu, Chiba Pref., 17-III-2016 (as larva on M. pinnata), emerged on 27-IV-2016, NSMT-I-Dip 31919.

Japan: On Marchantia papillata grossibarba: 9♂9♀, Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 26-V-2021 (as larva), emerged on 11-VI–2-VII-2021; 3♂3♀, Tsudono, Aoi-ku, Shizuoka Pref., 30-XI-2014 (as larva), emerged on 29-VII–9-VIII-2021; 6♂6♀, Naiku, Oe, Fukuchiyama, Kyoto Pref., 19-V-2021 (as larva), emerged on 1–16-VI-2021; 2♂, Muramatsu, Iwakura, Sakyo-ku, Kyoto Pref., 27-X-2017 (as larva), emerged on 9-XII-2017; 5♂1♀, Nagabuchi, Ume, Saeki, Oita Pref., 29-XI-2011 (as larva), emerged on 1–5-V-2011; 1♂9♀, Mt. Osuzu, Tsuno, Miyazaki Pref., 11-IV-2021 (as larva), emerged on 16–25-V-2021.

On Marchantia emarginata cuneiloba: 2♀, Takae, Higashi-son, Kunigami, Okinawa Pref., 11-XI-2021 (as larva), emerged on 22–28-XI-2021; 2♂2♀, Nagura, Ishigaki Is., Yaeyama, Okinawa Pref., 7-XI-2021 (as larva), emerged on 13-XI–16-XII-2021.

On Marchantia pinnata: 1♀, Jizodo, Mariya, Kisarazu, Chiba Pref., 17-III-2016 (as larva), emerged on 27-IV-2016.

A small black species (wing length 1.3–1.6 mm) having subshiny black scutum with an oval yellow pattern extending from mid-posterior margin to scutellum, black 1^st flagellomere, yellow maxillary palpus, yellow halteres, and brownish legs. Male epandrium with a comb comprising seven fused tubercle-like setae, and surstylus with a comb comprising three fused tubercle-like setae. Larva mines the thallus of Marchantia emarginata cuneiloba, M. papillata grossibarba and M. pinnata.

Adult male (Fig. 8A–E).

Head : Head light yellow, with ocellar triangle yellow but ocellar tubercle dark brown, back of head dark brown (Fig. 8C). Frons light yellow, with reflective pruinosity. Antenna porrect, first flagellomere dark brown, pedicel and scape brown. Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena light yellow. Proboscis normal, pale yellow; palpus dark yellow, cylindrical (Fig. 8B). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 8B). Orbital setulae minute and erect, in a single row.

Figure 8. 

Phytoliriomyza nubatama sp. nov. A–D, G holotype male A habitus B lateral C frontal D dorsal E, F paratype female (MK-AG-323), E dorsal F frontal G–L male genitalia (G–K type locality L Kume Island) G whole genitalia, ventral H phallic complex, lateral I epandrium, ventral J ejaculatory apodeme lateral K postgonite L phallic complex, ventral.

Thorax : Thorax subshiny. Scutum black. Scutellum black, medially with a small, obscure yellow patch; subscutellum black, anterior margin light yellow (Fig. 8D). Mediotergite dark brown, anatergite and katatergite light yellow. Pleuron largely light yellow; postpronotal lobe with anterior brown patch; notopleuron brownish yellow; anepisternum and anepimeron grayish yellow with brown spots on venters; katepisternum an meron with large dark brown patches on venter (Fig. 8B). Haltere light yellow, stalk grayish yellow. Calypter margin and hairs gray. Leg segments brown; basal half of femur brownish yellow. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 8D). Acrostichal setulae five pairs in two rows. Wing: Wing length 1.3 mm, costa reaching M₁ (Fig. 8A). Length of ultimate section of vein M₄ divided by penultimate section 1.0–1.3.

Abdomen : Abdomen dorsally subshiny dark brown. Genitalia: (Fig. 8G–L) Epandrium dark brown, rounded apically, inner-lateral surface with a comb comprising seven or eight fused long tubercle-like setae (Fig. 8I). Surstylus rounded; curved inwards, only sparsely setose apically; with a comb comprising three long fused tubercle-like setae on posterior margin (Fig. 8I). Cercus narrow, setose. Subepandrial sclerite with one pair of pale, broad, plate-like ventral process (Fig. 8I). Hypandrium slightly sclerotized along outer margin (Fig. 8G). Postgonite bare, goose barnacle-shaped, and cleft apically; upper lobe pointed apically (Fig. 8K). Phallophorus with deep incision below (Fig. 8G), articulated with phallapodeme, fused to epiphallus. Basiphallus 1/2 length of mesophallus (Fig. 8H). Basiphallus with narrow plate-like dorsal sclerite (Fig. 8H). Hypophallus membranous with lateral margins lightly sclerotized, medially with a pair of fused linear ventrally incurved sclerites (Fig. 8H, L). Paraphallus membranous supported by a pair of narrow plate-like pigmented sclerites (Fig. 8H, L). Mesophallus dark, cylindrical, S-curved in lateral view, longer than distiphallus (Fig. 8H). Distiphallus comprising one pair of stout tubules; each cylindrical, with a weak constriction medially, dorsally and laterally pigmented; with truncated apex; opening with indentation (Fig. 8H). Ejaculatory apodeme wide fan-shaped with narrow stalk and stout base; sperm pump clear with ventral sclerotized bar (Fig. 8J).

Female (Fig. 8F). Similar to male, but slightly larger and frons wider. Wing length 1.4–1.6 mm. Postabdomen: (Fig. 9A, B) Oviscape dark brown, setigerous (Fig. 9A). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 9B). Each cercus with two stout, apical, trichoid sensilla, 1/2 length of cercus (Fig. 9B). Spermathecae semi-orbicular (Fig. 9A).

Figure 9. 

Female morphology (A, B) and larval/adult ecology of Phytoliriomyza nubatama sp. nov. (C–E at Tazukawa-keikoku F, G at Inago) A, B female postabdomen at type locality A oviscape and spermatheca B tergite 10 C landscape of riparian habitat D–G mined thalli of Marchantia papillata grossibarba (arrows indicate internal puparia) H, I live female flies at Iriomote Is on thalli of Marchantia emarginata cuneiloba.

The specific name nubatama is a Japanese word meaning glossy black seed of the blackberry lily (Iris domestica (L.) Goldblatt & Mabb.), to which morphology of adult fly’s scutum of this species is likened.

Nubatama-tosazenigoke-hamoguribae.

Marchantia emarginata cuneiloba, M. papillata grossibarba and M. pinnata (Marchantiaceae).

Larvae construct linear mines in the thallus, and pupate in the midrib of the mined thalli (Fig. 9D–G).

The main habitats of this species are river banks where Marchantia papillata grossibarba grew on rocky substrate (Fig. 9C). In Izu Islands and Ryukyu Islands, the host plant species Marchantia emarginata cuneiloba is found on damp banking and levee of paddy fields. Our rearing records suggest that this species is multivoltine.

Japan: Honshu, Shikoku, Kyushu, Amami, Okinawa and Yaeyama Islands (Fig. 2).

This species resembles P. foliocerotis in glossy black scutum and black scutellum with small yellow spot; it is distinguished from the latter by the black 1^st flagellomere (yellow in P. foliocerotis).

Holotype: Japan: 1♂ (MK-AG-246), Higashinakama, Sumiyo, Amami, Kagoshima Pref. (28.269613°N, 129.436562°E, 340 m asl), 21-II-2015 (as larva on Dumortiera hirsuta), emerged on 1-IV-2015, NSMT-I-Dip 31920. Paratypes: Japan: 1♂2♀ (MK-AG-a486, a487, a488), same data as holotype, emerged on 30-III–7-IV-2015, NSMT-I-Dip 31921–31923; 1♀ (MK-AG-267), Abe-toge, Aoi-ku, Shizuoka Pref., 1-V-2015 (as larva), emerged on 18-V-2015, NSMT-I-Dip 31924; 1♀ (MK-AG-241), Narutaki, Ichiu, Tsurugi, Tokushima Pref., 12-VI-2017 (as larva), emerged on 21-VI-2017, NSMT-I-Dip 31926; 1♀ (MK-AG-282), Isso, Yaku Is., Kumage, Kagoshima Pref., 29-III-2017 (as larva), emerged on 2-V-2017, NSMT-I-Dip 31927; 1♀ (MK-AG-250), Nagakumo-toge, Tatsugo, Oshima, Kagoshima Pref., 23-II-2016 (as larva), emerged on 25-III-2015, NSMT-I-Dip 31928.

Japan: 5♂4♀, Abe-toge, Aoi-ku, Shizuoka Pref., 5-I-2015 (as larva), emerged on 18-V-2016; 2♂3♀, Tango-kanzaki, Maizuru, Kyoto Pref., 19-V-2021 (as larva), emerged on 30-V–5-VI-2021; 1♂1♀, Tategasaki, Kumano, Mie Pref., 23-IV-2021 (as larva), emerged on 11-V-2021; 3♀, Gakuen-ji, Bessho, Izumo, Shimane Pref., 31-III-2015 (as larva), emerged on 9-V-2015; 3♂1♀, Tazukawa-keikoku, Katsuura, Tokushima Pref., 30-III-2021 (as larva), emerged on 11–20-V-2021; 3♂4♀, Narutaki, Ichiu, Tsurugi, Tokushima Pref., 12-VI-2017 (as larva), emerged on 17–21-VI-2017; 1♀, Tashiro, Kinko, Kimotsuki, Kagoshima Pref., 22-III-2015 (as larva), emerged on 1-V-2015; 1♂1♀, Isso, Yaku Is., Kumage, Kagoshima Pref., 11-III-2016 (as larva), emerged on 617–19-IV-2016; 11♂14♀, Higashinakama, Sumiyo, Amami, Kagoshima Pref., 21-II-2015 (as larva), emerged on 30-III–8-IV-2015.

A large dark species (wing length 1.9–2.2 mm) having subshiny dark brown scutum, brownish yellow scutellum, black 1^st flagellomere, dark maxillary palpus, dark halteres, and dark gray legs. Male epandrium inner-laterally with an incomplete comb comprising three short, fused, tubercle-like setae medially. Larva mines the thallus of Dumortiera hirsuta.

Adult male (Fig. 10A–D).

Head : Head largely light yellow; ocellar triangle yellow but ocellar tubercle dark brown; front-orbital plate brown; back of head brown above foramen excluding margin (Fig. 10C). Antenna porrect, first flagellomere black, pedicel and scape brown. Arista subbasal, pubescent. Face, gena, parafacial and postgena light yellow. Proboscis normal, yellow; palpus brown, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 10B). Orbital setulae minute and erect, in a single row.

Figure 10. 

Phytoliriomyza dumortierae sp. nov. A–D holotype male A habitus B lateral C frontal D dorsal E paratype female (MK-AG-241) F–L male genitalia (F at type locality G–I at Ichiu J–L at Tashiro) F whole genitalia, ventral G whole genitalia, lateral H phallic complex, lateral I ejaculatory apodeme, lateral J phallic complex, ventral K–L epandrium, posterior and anterior.

Thorax : Thorax subshiny. Scutum dark brown with a pair of terminal yellow patches adjoining scutellum (Fig. 10D). Scutellum yellow with lateral corner narrowly brown. Mediotergite, katatergite and anatergite dark brown. Pleuron yellow, lower half of anepisternum and anepimeron brown, meron and katepisternum brown (Fig. 10B). Haltere light yellow. Calypter margin and hairs gray. Leg segments brown; tibia and tarsus dark brown. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly. Acrostichal setulae seven or eight pairs in two rows (Fig. 10D). Wing: Wing length 1.9 mm, costa reaching M₁ (Fig. 10A). Length of ultimate section of vein M₄ divided by penultimate section 1.2.

Abdomen : Abdomen dorsally subshiny brown (Fig. 10A). Genitalia: (Fig. 10F–L) Epandrium dark brown rounded apically, onion-shaped in lateral view (Fig. 10G); inner-anterior margin with two stout tubercle-like setae, and inner-lateral margin with an incomplete comb comprising three short, fused, tubercle-like setae medially (Fig. 10K, L). Surstylus with a row of seven or eight strong setae apically and one or two stout tubercle-like setae posteriorly. Subepandrial sclerite with one pair of long, ventrally directed arms; distal end flattened and expanded (Fig. 10F). Hypandrium sclerotized along outer margin (Fig. 10F). Postgonite bare and goose barnacle-shaped with a pointed apex (Fig. 10J). Phallophorus articulated with phallapodeme, fused to epiphallus (Fig. 10H, J). Basiphallus consisting of a pair of asymmetric dark narrow plate-like sclerites; both protruding ventrally (Fig. 10F–H, J). Hypophallus broad and membranous with lateral margin sclerotized, medially with a pair of short converging sclerites (Fig. 10H, J). Paraphallus narrow, membranous and distally pointed, with distal tip pigmented (Fig. 10F–H, J). Mesophallus dark, turgid, widest subbasally, as long as distiphallus (Fig. 10H). Distiphallus comprising one pair of stout tubules; basal 1/3 composed of dark sclerite basally and weaker medial region; distal 2/3 dark, claviform, tip rounded (Fig. 10H). Ejaculatory apodeme fan-shaped with marginal pale area and broad stalk; base dark and wide to one side; sperm pump clear (Fig. 10I).

Female (Fig. 10E). Similar to male, but slightly larger. Wing length 2.2 mm. Postabdomen: (Fig. 11A, B) Oviscape dark brown sparsely setigerous (Fig. 11A). Tergite 10 trifurcate, laterally uniting narrow pleural sclerites (Fig. 11B). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus. Spermathecae semi-orbicular, with truncate proximal ends (Fig. 11A).

Figure 11. 

Female morphology and larval ecology of Phytoliriomyza dumortierae sp. nov. A, B female postabdomen at type locality A oviscape and spermatheca B tergite 10 C–I habitat and the host liverwort Dumortiera hirsuta C mined thallus at Gakuenji D habitat at type locality E mined thallus at type locality (an arrow indicates internal puparium) F an internal puparium in thallus at Tazukawa-keikoku G habitat at Ichiu, H, I mined thalli at Ichiu.

The color of frons and scutellum varies from yellow to brownish yellow in some localities.

The specific name refers to its host plant genus Dumortiera.

Zangetsu-kezenigoke-hamoguribae.

Dumortiera hirsuta (Dumortieraceae).

(Fig. 11C, E, F, H, I) Larvae construct linear mines in the midrib of the thallus in early instars, and in the last instar construct radiate or blotch mines by coming out from the midrib, and pupate in the mines.

The main habitats of this species are along streams in warm temperate evergreen forests (Fig. 11D, G). Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Japan: Honshu, Shikoku, Kyushu, Yaku Island and Amami-oshima Island (Fig. 12).

Figure 12. 

Locality records of three Phytoliriomyza species associated with Dumortiera spp.: P. dumortierae and P. crepusculum.

This species resembles P. wiesnerellae in coloration of head, thorax, abdomen, and legs; it is distinguished from the latter by the pleuron with the lower half darkened (pleuron almost wholly yellow in P. wiesnerellae). The great morphological difference in male genitalia suggests that these two species are not closely related.

Holotype: Japan: 1♂ (MK-AG-a29), Naiku, Oe, Fukuchiyama, Kyoto Pref. (35.433016°N, 135.150397°E, 75 m asl), 17-III-2017 (as larva), emerged on 17-V-2017, NSMT-I-Dip 31929. Paratypes: Japan: 1♂ (MK-AG-a457), type locality, 19-V-2021 (as larva), on 1-VII-2021, NSMT-I-Dip 31930; 1♂1 ♀ (MK-AG-a399, 274), Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 17-II-2002 (as larva), emerged on 17–23-IV-2002, NSMT-I-Dip 31931, 31932; 1♂ (MK-AG-a309), Mitake, Kamitsushima, Nagasaki Pref., 19-IV-2009 (as larva), emerged on 6-VI-2009, NSMT-I-Dip 31933.

Japan: 1♀, Sanekawa-keikoku, Iide, Aga, Higashikanbara, Niigata Pref., 3-V-2015 (as larva), emerged on 12-VI -2015; 1♀, Mt. Kiyosumi, Kamogawa, Chiba Pref., 24-I-2012 (as larva), emerged on 25-V–5-VI-2012; 17♂32♀, Inago, Shibakawa, Fujinomiya, Shizuoka Pref., 17-II-2002 (as larva), emerged on 23-IV–5-VI-2021; 1♂, Shogawa-kyo, Tonami, Toyama Pref., 3-V-2016 (as larva), emerged on 9-VI -2016; 1♀, Takeda-gawa, Maruoka, Sakai, Fukui Pref., 6-IV-2002 (as larva), emerged on 13-VI-2019; 2♂2♀, Mt. Nabejiri, Taga, Shiga Pref., 23-V-2015 (as larva), emerged on 26–15-VI-2015; 1♂1♀, Boumura, Kazuragawa, Otsu, Shiga Pref., 7-IV-2002 (as larva), emerged on 24-V-2002; 1♂1♀, Mitake, Kamitsushima, Nagasaki Pref., 9-IV-2009 (as larva), emerged on 6-VI-2009.

A medium-sized species (wing length 1.4–1.8 mm) having subshiny brown scutum with brownish yellow pattern extending from mid-posterior margin to scutellum, black 1^st flagellomere, brown maxillary palpus, brown halteres, and brownish yellow legs. Male epandrium inner-laterally with a comb comprising five long fused tubercle-like setae. Larva mines the thallus of Dumortiera hirsuta.

Adult male (Fig. 13A–D).

Head : Head largely light yellow; ocellar triangle yellow but ocellar tubercle dark brown; back of head dark brown above foramen excluding margin (Fig. 13C). Antenna porrect, first flagellomere black, pedicel and scape yellow. Arista subbasal, pubescent. Face, gena, parafacial and postgena light yellow. Proboscis normal, yellow; palpus yellow, cylindrical. Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 13B). Orbital setulae minute and erect, in a single row.

Figure 13. 

Phytoliriomyza crepusculum sp. nov. A–C holotype male A habitus B lateral C frontal D paratype male (MK-AG-a309), dorsal E paratype female (MK-AG-274), dorsal F–I male genitalia F ejaculatory apodeme, dorsal G whole genitalia, ventral H phallic complex, lateral I epandrium, ventral J puparium K–L female postabdomen K oviscape and spermatheca L tergite 10 M habitat of type locality N–P mined thalli of Dumortiera hirsuta (N type locality O Kiyosumi P Mt. Nabejiri). An arrow in N indicate an puparium.

Thorax : Thorax subshiny. Scutum brown with a large posterior trapezoid yellow patch adjacent to scutellum (Fig. 13D). Scutellum yellow with lateral corner narrowly brown. Subscutellum yellow. Mediotergite, katatergite and anatergite brown. Pleuron yellow, but propleuron, meron, anepimeron centrally pale brown (Fig. 13B). Haltere brown. Calypter margin and hairs gray. Leg segments yellow; tibia and tarsus dorsally brown (Fig. 13D). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 13D). Acrostichal setulae five pairs in two rows. Wing: Wing length 1.4 mm, costa reaching M₁ (Fig. 13A). Length of ultimate section of vein M₄ divided by penultimate section 1.1.

Abdomen : Abdomen dorsally subshiny brown (Fig. 13D). Genitalia: (Fig. 13F–I) Epandrium dark brown, rounded apically; posterior end of inner margin with a stout tubercle-like seta; inner-ventral surface of epandrium with a comb comprising five fused long tubercle-like setae; inner-ventral margin with a row of several short tubercle-like setae (Fig. 13I). Surstylus rounded, directed inwards, setose apically but without tubercle-like seta. Cercus narrow, setose. Subepandrial sclerite with one pair of posteriorly directed plate-like arms (Fig. 13I). Hypandrium slightly sclerotized along outer margin (Fig. 13G). Postgonite bare, goose barnacle-shaped, narrowly rounded, and cleft apically (Fig. 13H). Phallophorus with deep incision below (Fig. 13G), and articulated with phallapodeme, fused to epiphallus (Fig. 13H). Basiphallus composing of a left anterodorsal sclerite and a right L-shaped lateral sclerite; former narrow, protruding rightward, the latter protruding ventrally (Fig. 13G–H). Hypophallus broad and membranous, supported by one pair of fused sclerites ventrally (Fig. 13G, H). Mesophallus dark, cylindrical, widest subbasally, slightly shorter than distiphallus (Fig. 13H). Distiphallus consists of a pair of moderately long tubules slightly diverging apically; basal half composed of dark narrow lobate sclerite and weaker medial region; distal half cylindrical, dorsally pigmented, with truncated, unpigmented apex (Fig. 13H). Ejaculatory apodeme fan-shaped with short broad stalk, broad base, and clear sperm pump (Fig. 13F).

Female (Fig. 13E). Similar to male (Fig. 13E). Wing length 1.4–1.8 mm. Postabdomen: (Fig. 13K, L) Oviscape brown sparsely setigerous on lateral sides (Fig. 13K). Tergite 10 trifurcate, laterally uniting narrow pleural sclerites (Fig. 13L). Cercus with two stout, apical, trichoid sensilla, ca. 1/2 length of cercus (Fig. 13L). Spermathecae semi-orbicular, with truncate proximal ends (Fig. 13K).

Immatures. (Fig. 13J) Puparium internal, slender, and pale brown.

The specific name (crepusculum = twilight) refers to the brownish yellow patch on the scutum.

Yuuzuki-kezenigoke-hamoguribae.

Dumortiera hirsuta (Dumortieraceae).

(Fig. 13N–P) Larvae mine the midrib of the thallus in early instars, later construct radiate mines by coming out from the midrib, and pupate in the mines. Puparium is smooth and pale brown, posterior spiracles projecting (Fig. 13J).

The main habitats of this species are along streams in warm temperate forests and cool temperate deciduous forests (Fig. 13M), and this species was sympatric with P. dumortierae in some localities. Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Japan: Honshu, Shikoku, Kyushu, Tsushima Island (Fig. 12).

Although this species used the same host plant as P. dumortierae, these two species were not sympatric in any localities. This species resembles P. arcus, P. plagiochasmatos and P. falcata in having a pair of brown lateral bands on the scutum; it is distinguished from them by the brownish yellow color of the medial mark on scutum (light yellow in the other species).

Holotype: Japan: 1♂ (MK-AG-a411), Nippara, Okutama, Tokyo Pref. (35.8504°N, 139.0274°E, 650 m asl), 15-III-2016 (as larva on P. pterospermum), emerged on 28-IV-2016, NSMT-I-Dip 31934. Paratypes: Japan: 1♂1♀ (MK-AG-a16, a458), same data as holotype, emerged on 4–5-V-2016, NSMT-I-Dip 31935, 31937; 1♀ (MK-AG-191), Akka, Iwaizumi, Iwate Pref., 5-V-2012 (as larva on P. pterospermum), emerged on 13-V-2012, NSMT-I-Dip 31936; 1♀ (MK-AG-a316), Mt. Myogi, Tomioka, Gunma Pref., 10-V-2021 (as larva on P. pterospermum), emerged on 16-V-2021, NSMT-I-Dip 31938; 1♀ (MK-AG-189), Todai-shiraiwa, Ina, Nagano Pref., 30-IV-2011 (as larva on P. pterospermum), emerged on 28-V-2011, NSMT-I-Dip 31939.

Japan: On Plagiochasma pterospermum: 4♂4♀, Akka, Iwaizumi, Iwate Pref., 5-V-2012 (as larva), emerged on 27–28-V-2012; 9♂9♀, Mt. Myogi, Tomioka, Gunma Pref., 10-V-2021 (as larva), emerged on 14–21-V-2021; 10♂12♀, Narahara, Ueno, Tano, Gunnma Pref., 18-IV-2021 (as larva), emerged on 15–25-V-2021; 2♂5♀, Mt. Kano, Kanna, Tano, Gunma Pref., 28-XI-2014 (as larva), emerged on 4-V-2015; 2♂1♀, Mt. Futago, Ogano, Chichibu-gun, Saitama Pref., 10-IX-2017 (as larva), emerged on 20-X–12-XI-2017; 1♂3♀, Kanna-gawa, Nakatsugawa, Chichibu, Saitama Pref., 16-X-2012 (as larva), emerged on 5-V-2012; 9♂11♀, Todai-shiraiwa, Ina, Nagano Pref., 12-V-2021 (as larva), emerged on 1–13-VI-2021.

On Plagiochasma appendiculatum: 5♂4♀, Mt. Myogi, Tomioka, Gunma Pref., 10-V-2021 (as larva), emerged on 15–29-V-2021.

A small species (wing length 1.3–1.6 mm) having subshiny brown scutum with yellow pattern extending from mid-posterior margin to scutellum, yellow 1^st flagellomere, yellow maxillary palpus, yellow halteres, and yellow legs. Male epandrium inner-subdistally with hypertrophied, elongated, strongly curved arm bearing a dark tubercle-like seta. Larva mines the thallus of Plagiochasma pterospermum and P. appendiculatum.

Adult male (Fig. 14A–E).

Head : Head light yellow, with ocellar tubercle brown, back of head dark brown (Fig. 14C). Antenna porrect, first flagellomere, pedicel and scape brown. Arista subbasal, black pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; yellow, cylindrical (Fig. 14C). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 14B). Orbital setulae minute and erect, in a single row.

Figure 14. 

Phytoliriomyza arcus sp. nov. A–E holotype male A habitus B lateral C frontal D dorsal E posterior F paratype female (MK-AG-a16), dorsal G–K male genitalia (G at type locality H–K at Todai-shiraiwa) G, H whole genitalia, ventral I phallic complex, lateral J ejaculatory apodeme, lateral K epandrium, ventral.

Thorax : Thorax subshiny. Scutum subshiny yellow, with a brown medial stripe on anterior 2/3, one pair of brown presutural patches, and a pair of wide postsutural brown bands adjoining with the presutural patches (Fig. 14D). Mediotergite brown, and anatergite and katatergite yellow. Pleuron largely yellow, anepisternum and anepimeron with small brown patches, venters of katepisternum and meron brown (Fig. 14B). Haltere gray. Calypter margin and hairs gray. Leg segments yellow; tibia and tarsus darker (Fig. 14A). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly. Acrostichal setulae six pairs in two rows (Fig. 14D). Wing: Wing length 1.3 mm, costa reaching M₁ (Fig. 14A). Length of ultimate section of vein M₄ divided by penultimate section 1.7–1.8.

Abdomen : Abdomen dorsally subshiny grayish yellow (Fig. 14E). Genitalia: (Fig. 14G–K) Epandrium dark brown, rounded apically; inner-lateral margin with an incomplete comb comprising two or three short tubercle-like setae; inner subdistal surface with basally thickened, remarkably elongated, strongly curved arm bearing a dark tubercle-like seta apically (Fig. 14G, H, K). Surstylus protruding ventrally, tapering toward apex, setose apically, with one short tubercle-like seta on inner-basal surface (Fig. 14K). Cercus narrow, setose. Subepandrial sclerite V-shaped in posterior view, with a pair of ventrally projected plate-like lobes with a spine medially (Fig. 14K). Hypandrium slightly sclerotized along outer margin (Fig. 14G). Postgonite bare, goose barnacle-shaped, and cleft apically (Fig. 14G). Phallophorus with deep incision below, articulated with phallapodeme, fused to epiphallus (Fig. 14I). Basiphallus with a H-shaped dorsal sclerite; anterior arms of which protruding ventrolaterally (Fig. 14G–I). Hypophallus broad, membranous with microtrichia scattered dorsally, medially with a pair of short confronting sclerites (Fig. 14G–I). Paraphalli wing-like, lightly sclerotized posteriorly; diverging, angled anteroventrally, joined basally on to the base of mesophallus. Mesophallus dark, cylindrical, widest subbasally, as long as distiphallus (Fig. 14G–I). Distiphallus comprising one pair of stout tubules; basal half composed of lateral dark sclerites and weaker medial region; distal half cylindrical, composed of a pair of dorsally and laterally pigmented sclerites, widening toward apex, with truncated, flared apex (Fig. 14I). Ejaculatory apodeme pale and fan-shaped with broad stalk; base wide to one side; sperm pump clear.

Female (Figs 14F, 15C). Similar to male, but slightly larger (Fig. 14F). Wing length 1.6 mm. Postabdomen: (Fig. 15A, B) Oviscape dark brown, setigerous (Fig. 15A). Tergite 10 trifurcate, laterally uniting narrow pleural sclerites (Fig. 14B). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus (Fig. 14B). Spermathecae semi-orbicular, with truncate proximal ends (Fig. 14A).

Figure 15. 

Female morphology and larval/adult ecology of Phytoliriomyza arcus sp. nov. A, B female postabdomen A oviscape and spermatheca at Shiraizasu B tergite 10 at Mt. Myogi C live fly at Mt. Myogi D habitat at type locality E mined thallus of Plagiochasma pterospermum at Mt. Myogi F mined thalli at Todai-shiraiwa.

The yellow posterior patch on the scutum varied from distinct to obscure ones among localities and even among individuals in some localities.

The specific name (arcus = bow) refers to the bow-shaped tubercle-like seta on the male epandrium.

Yumihari-tsubozenigoke-hamoguribae.

Plagiochasma pterospermum and P. appendiculatum (Aytoniaceae).

Larvae construct linear-blotch mines in the thallus and pupate in the mines (Fig. 15D–F).

The habitats of this species are limestone outcrops in temperate deciduous forests, where the host liverworts grow (Fig. 15D). Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Japan: Honshu (Fig. 16). Recorded only from limestone areas in Tohoku and Kanto districts.

Figure 16. 

Locality records of three Phytoliriomyza species associated with Plagiochasma spp.: P. arcus, P. plagiochasmatos and P. calcicola.