32. Phytoliriomyza conocephali Kato sp. nov.

Figs 59, 60

Material examined.

Holotype: Japan: 1♂ (MK-AG-a269), Ashiu, Nantan, Kyoto Pref. (35.3261°N, 135.7239°E, 450 m asl), 29-XI-1998 (as larva on Conocephalum orientalis), emerged on 26-V-1999, NSMT-I-Dip 32076. Paratypes: Japan: 1♂ (MK-AG-a408), type locality, 8-IV-2012 (as larva on Conocephalum orientalis), emerged on 13-V-2012, NSMT-I-Dip 32077; 2♂ (MK-AG-a444, a445), Ashiu, Nantan, Kyoto Pref., 13-XI-2001 (as larva on C. japonicum), emerged on?-IV-2019, NSMT-I-Dip 32078-32079; 1♂ (MK-AG-a9), Soun-kyo, Kamikawa, Hokkaido, 18-X-2018 (as larva on C. japonicum), emerged on 7-V-2019, NSMT-I-Dip 32080; 1♂ (MK-AG-a8), Dainichi, Kakegawa, Shizuoka Pref., 3-I-2016 (as larva on C. japonicum), emerged on 24-IV-2016, NSMT-I-Dip 32081; 1♀ (MK-AG-726), Saruyama, Monzen, Wajima, Ishikawa Pref., 4-V-2013 (as larva on C. orientalis), emerged on 3-VI-2013, NSMT-I-Dip 32082; 1♀ (MK-AG-a7), Muramatsu, Iwakura, Sakyo-ku, Kyoto Pref., 2-III-2019 (as larva on C. orientalis), emerged on 16-IV-2019, NSMT-I-Dip 32083; 1♀ (MK-AG-a6), Chikatsuyu, Nakaheji, Tanabe, Wakayama Pref., 3-III-2012 (as larva on C. orientalis), emerged on 9-IV-2012, NSMT-I-Dip 32084.

Other material.

Japan: On C. orientalis: 3♂3♀, Yusen-kyo, Yamadera, Yamagata Pref., 15-IV-2012 (as larva), emerged on 19-V-2-VI-2012; Hosorogi, Awara, Ishikawa Pref., 1-IV-2011 (as larva), emerged on 5-24-V-2011; 4♂3♀, Suizu, Tsuruga, Fukui Pref., 11-III-2012 (as larva), emerged on 12-IV-8-V-2012; 1♂♀, Seryo, Sakyo-ku, Kyoto Pref., 22-IX-2002 (as larva), emerged on 15-16-V-2002; 5♂15♀, Muramatsu, Iwakura, Sakyo-ku, Kyoto Pref., 5-IV-2017 (as larva), emerged on 12-22-IV-2017; 1♂2♀, Mt. Gyojagaeri, Kamikitayama, Nara Pref., 31-VII-1999 (as larva), emerged on 25-VIII-5-X-1999; 4♂5♀, Wadagawa-kyo, Kumanogawa, Shingu, Wakayama Pref., 7-VII-2021 (as larva), emerged on 26-VII-5-VIII-2021; 6♀, Wabuka, Kushimoto, Wakayama Pref., 4-III-2012 (as larva), emerged on 9-IV-23-V-2017; 2♂8♀, Taishaku-kyo, Shobara, Hiroshima Pref., 9-IV-2011 (as larva), emerged on 15-27-V-2011; 2♂4♀, Narutaki, Ichiu, Tsurugi, Tokushima Pref., 31-III-2021 (as larva), emerged on 11-V-2-VI-2021; 1♂1♀, Yasui-keikoku, Niyodogawa, Agawa, Kochi Pref., 27-II-2011 (as larva), emerged on 24-26-IV-2011; 2♂14♀, Nanatsudake, Tamanoura, Fukue Is. Goto, Pref., 9-X-1998 (as larva), emerged on 20-XI-1998-4-IV-1999; 3♂4♀, Gokanosho, Itsuki, Kumamoto Pref., 10-IV-2021 (as larva), emerged on 10-221-IV-2021; 1♂4♀, Anbo, Yaku Is., Kumage, Kagoshima Pref., 30-II-2017 (as larva), emerged on?-V-2017.

On Conocephalum purpureorubrum: 2♀, Toikanbetsu, Horonobe, Teshio, Hokkaido Pref., 5-X-2013 (as larva), emerged on?-V-2013; 1♀, Yoro-keikoku, Otaki, Isumi, Chiba Pref., 17-III-2016 (as larva), emerged on 22-IV-2013; 1♀, Shirabiso-toge, Kamimura, Iida, Nagano Pref., 14-X-2011 (as larva), emerged on 18-V-2012.

On Conocephalum salebrosum: 1♀, Shirabiso-toge, Kamimura, Iida, Nagano Pref., 14-X-2011 (as larva), emerged on 18-V-2012; 1♂, Usuzuka, Fujinomiya, Shizuoka Pref., 15-VI-2013 (as larva), emerged on 8-VII-2013.

On Conocephalum japonicum: 1♂1♀, Mt. Teine, Teine-ku, Sapporo, Hokkaido, 24-VII-2011 (as larva), emerged on 15-17-VIII-2011; 1♂4♀, Nishikawa, Nishimurayama, Yamagata Pref., 15-IV-2011 (as larva), emerged on 19-V-8-VI-2012; 4♂8♀, Dainichi, Kakegawa, Shizuoka Pref., 3-I-2016 (as larva), emerged on 21-IV-1-V-2016; 4♂8♀, Soun-kyo, Kamikawa, Hokkaido, 18-X-2016 (as larva), emerged on 20-IV-7-V-2016; 4♂5♀, Wadagawa-kyo, Kumanogawa, Shingu, Wakayama Pref., 7-VII-2021 (as larva), emerged on 26-VII-5-VIII-2021; 3♂4♀, Gokanosho, Itsuki, Kumamoto Pref., 10-IV-2021 (as larva), emerged on 10-221-IV-2021.

Diagnosis.

A small dark species (wing length 1.3-1.7 mm) having a pruinose dark gray scutum with a mid-posterior yellow margin, a yellow scutellum with dark lateral corners, a black 1st flagellomere, dark maxillary palpus, dark halteres, and yellowish brown legs. Male epandrium inner-subdistally with a long ventrally directed tubercle-like seta, inner-laterally with a tubercle like seta, and inner-basally with a comb comprising five fused tubercle-like setae. Larva mines the thallus of all Japanese Conocephalum spp.

Description.

Adult male (Fig. 59A-E).

Head: Head light yellow, with ocellar tubercle dark brown, frons yellowish brown, back of head dark brown excluding margins (Fig. 59C). Antenna porrect, first flagellomere black, pedicel and scape brown (Fig. 59B). Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus brown, cylindrical (Fig. 59C). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 59D). Orbital setulae minute and erect, in a single row.

Thorax: Thorax pruinose. Scutum pruinose gray, with a small yellow patch along midposterior margin (Fig. 59D). Scutellum light yellow with lateral corner brown, subscutellum light yellow. Mediotergite and anatergite brown, katatergite light yellow (Fig. 59E). Pleuron yellow with brownish patches on venter of propleuron, anepisternum, katepisternum, anepimeron, and meron (Fig. 59B). Haltere brown. Calypter margin and hairs gray. Leg segments brownish, basal half of femur paler (Fig. 59A). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 59D). Acrostichal setulae five or six pairs in irregular two rows. Wing: Wing length 2.2 mm, costa reaching M1 (Fig. 59A). Length of ultimate section of vein M4 divided by penultimate section 1.3.

Abdomen: Abdomen dorsally subshiny brown; epandrium dark brown (Fig. 59E). Genitalia: (Fig. 59G-K) Epandrium rounded apically; inner-subposterior surface with a l tubercle-like seta; inner-lateral margin with a long, anteriorly directed, tubercle-like seta; inner-anterior surface with a comb comprising five or six fused long tubercle-like setae (Fig. 59K). Surstylus oblong, curved inwards, setose apically, with two long tubercle-like setae on posterior subdistal margin (Fig. 59K). Cercus narrow, setose. Subepandrial sclerite V-shaped in a posterior view, with pale plate-like arms. Hypandrium slightly sclerotized along outer margin (Fig. 59G). Postgonite bare, goose barnacle-shaped, rounded apically (Fig. 59I). Phallophorus with deep incision below, articulated with phallapodeme, fused to epiphallus (Fig. 59G-I). Basiphallus with broad plate-like sclerite on left side. Hypophallus broad, membranous covered with microtrichia ventrally; medially with a pair of fused narrow ventrally incurved sclerites (Fig. 59G-I). Paraphallus pale membranous, bilobed; medial axis and margin lightly sclerotized; paraphalli spread laterally, jointed basally, resembling 4 wings (Fig. 59G-I). Mesophallus dark, cylindrical, as long as distiphallus (Fig. 59I). Distiphallus comprising one pair of stout tubules basally parallel to each other; basal half composed of ventral dark subtriangular sclerite and weaker medial region; distal half cylindrical, dorsally pigmented, widening toward truncated, flared apex (Fig. 59I). Ejaculatory apodeme pale brown, with fan-shaped blade and short broad stalk; base wide to one side; sperm pump clear (Fig. 59J).

Female (Figs 59F, 60C). Similar to male, but slightly larger; color of scutellum darker. Wing length 2.3 mm. Postabdomen: (Fig. 60A, B) Oviscape dark brown, setigerous (Fig. 60A). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 60B). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus (Fig. 60B). Spermathecae semi-orbicular, with truncate proximal ends (Fig. 60A).

Variation.

The color pattern of the scutellum varied among localities; individuals at some localities had a larger dark corner on the scutum. The number of tubercle-like setae in a comb of the male epandrium varied from 5 to 6 among localities, among individuals in the same locality and even between right and left combs of an individual. The number of tubercle-like setae on the surstylus was consistently two, but the direction of each varied among localities.

Etymology.

The specific name refers to the larval feeding on Conocephalum liverworts.

Japanese name.

Komorebi-jagoke-hamoguribae.

Host plants.

Conocephalum salebrosum, C. orientalis, C. purpureorubrum and C. japonicum ( Conocephalaceae).

Mine.

Larvae construct linear mines in the midrib of the thallus, and pupate in the mines (Fig. 60D-I). The mines on thick thalli of perennial C. orientalis are inconspicuous (Fig. D), while those on thin thalli of annual C. japonicum (Fig. E-I) are blackish and conspicuous.

Biological notes.

The habitats of this species are stream banks and mesic slopes in warm temperate evergreen forests dominated by Castanopsis cuspidata and cool temperate deciduous forests dominated by Quercus crispula . It is sympatric with P. izayoi, P. luteola, and P. lanternaria at some localities. Our rearing records suggest that this species is bivoltine, with adults emerging twice in spring and summer.

Distribution.

Japan: Hokkaido, Honshu, Shikoku, Kyushu, and Yaku Island (Fig. 61).

Remarks.

This species is the second smallest (next to P. suetsugui) among the Phytoliriomyza species associated with Conocephalum, and is the only species that mines the small thalli of C. japonicum . This species resembles P. marchantiae, P. rebouliae, and P. lanternaria in having a small yellow mark lying between the posterior scutum and the scutellum; it is distinguished from P. marchantiae and P. rebouliae by the presence of tubercle-like seta on the surstylus of the male epandrium, from P. lanternaria by the number of tubercle-like setae in a comb of the male epandrium (5-6 in P. conocephali; 7 in P. lanternaria).

This species also resembles P. miki and P. fumicosta in scutum color and male genitalia; it is distinguished from P. miki by the rounded surstylus (slender and elongated in P. miki), from P. fumicosta by the number of fused tubercle-like setae in a comb of the male epandrium (5-6 in P. conocephali; 7 in P. fumicosta).