Phytoliriomyza pallidofasciata Kato, 2022

Kato, Makoto, Yamamori, Luna & Imada, Yume, 2022, Diversity underfoot of agromyzids (Agromyzidae, Diptera) mining thalli of liverworts and hornworts, ZooKeys 1133, pp. 1-164 : 1

26. Phytoliriomyza pallidofasciata Kato sp. nov.

Fig. 49

Material examined.

Holotype: Japan: 1♂ (MK-AG-a519), Tazukawa-keikoku, Katsuura, Tokushima Pref. (33.8907°N, 134.4580°E, 310 m asl), 30-III-2021 (as larva), emerged on 27-IV-2021, NSMT-I-Dip 32045. Paratypes: Japan: 1♂2♀ (MK-AG-a538, a520, a537), same data as holotype, emerged on 27-IV-1-V-2016, NSMT-I-Dip 32046-32048; 1♀ (MK-AG-676), Asahi-daki, Shuzenji, Izu, Shizuoka Pref., 7-III-2012 (as larva), emerged on 20-IV-2012, NSMT-I-Dip 32049; 1♀ (MK-AG-a240) Mt. Ichifusa, Mizukami, Kuma, Kumamoto Pref., 14-XII-2012 (as larva), emerged on 22-III-2013, NSMT-I-Dip 32050.

Other material.

Japan: 3♂1♀, Momiki, Izumi, Yatsushiro, Kumamoto Pref., 23-III-2015 (as larva), emerged on?-VI-2015; 2♂, Yoro-keikoku, Otaki, Isumi, Chiba Pref., 17-III-2016 (as larva), emerged on 18-20-IV-2016; 1♂2♀, Amagi-toge, Izu, Shizuoka Pref., 19-IV-2012 (as larva), emerged on 8-V-3-VI-2021; 2♂2♀, Kuki, Owase, Mie Pref., 29-III-2019 (as larva), emerged on 9-30-IV-2019; 1♀, Takinohai, Kozagawa, Wakayama Pref., 13-IV-2014 (as larva), emerged on 19-IV-2014; 2♀, Wabuka, Kushimoto, Wakayama Pref., 4-V-2012 (as larva), emerged on 9-IV-2012; 7♂8♀, Narutaki, Ichiu, Tsurugi, Tokushima Pref., 31-III-2021 (as larva), emerged on 28-IV-20-V-2021; 1♂2♀, Yasui-keikoku, Niyodogawa, Agawa, Kochi Pref., 27-II-2011 (as larva), emerged on 25-IV-2011; 3♀, Mt. Kosho, Asakura, Fukuoka Pref., 11-IV-2010 (as larva), emerged on 1-13-V-2016; 1♂, Amagi-toge, Izu, Kaeda-keikoku, Kagamisu, Miyazaki, Miyazaki Pref. Pref., 11-IV-2021 (as larva), emerged on 19-IV-2021.

Diagnosis.

A medium-sized yellow species (wing length 1.9-2.0 mm) having pruinose yellow scutum with two pairs of pale brown stripes, a black 1st flagellomere, yellow maxillary palpus, yellow halteres, and yellow legs. Male epandrium inner-laterally with an extended, apically flattened tubercle-like seta, and inner-basally with a comb comprising 3-5 long fused tubercle-like setae. Larva mines the thallus of Conocephalum orientalis .

Description.

Adult male (Fig. 49A-E ).

Head: Head yellow, with back of head dark brown excluding margins (Fig. 49C ). Antenna porrect, first flagellomere black, pedicel and scape yellow (Fig. 49B ). Arista subbasal, black, pubescent. Clypeus, face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus yellow, cylindrical (Fig. 49C ). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 49B ). Orbital setulae minute and erect, in a single row.

Thorax: Thorax pruinose. Scutum yellow with a medial brownish yellow stripe on anterior 2/3, with a pair of narrow pale brown supra-alar stripes and a pair of wider pale brown intra-alar stripes, which adjoin a pair of lateral presutural pale brown ovoid spots (Fig. 49B ). Scutellum, subscutellum, mediotergite, anatergite and katatergite yellow (Fig. 49E ). Pleuron entirely yellow (Fig. 49B ). Haltere yellow. Calypter margin and hairs gray. Leg segments entirely yellow; tibia and tarsus darker. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 49D ). Acrostichal setulae eight or nine pairs in two irregular rows. Wing: Wing length 2.0 mm, costa reaching M1 (Fig. 49A ). Length of ultimate section of vein M4 divided by penultimate section 1.1-1.3.

Abdomen: Abdomen dorsally subshiny yellow; epandrium brown (Fig. 49E ). Genitalia: (Fig. 49 ) Epandrium rounded apically;inner-lateral surface with an elongated tubercle-like seta, whose tip papillate; inner-anterior surface with a comb comprising six or seven fused long tubercle-like setae (rarely unfused in part) and a row of 2-5 short tubercle-like setae immediately outward from the comb (Fig. 49J ). Surstylus rounded, directed inwards, setose apically, with one long tubercle-like seta on posterior margin (Fig. 49J ). Cercus narrow, setose. Subepandrial sclerite V-shaped in a posterior view; dorsal lobe plate-like, with a pair of setae basally (Fig. 49J ). Hypandrium slightly sclerotized along outer margin (Fig. 49G ). Postgonite bare and goose barnacle-shaped (Fig. 49G ). Phallophorus with deep incision below, articulated with phallapodeme, fused to epiphallus (Fig. 49G, I ). Basiphallus with broad plate on left side and lightly sclerotized anterodorsal margin (Fig. 49G ). Hypophallus membranous, covered with microtrichia ventrally; with margins lightly sclerotized; medially with a pair of dark fused, ventrally incurved narrow sclerites; a small tubule protruding ventrally from subdistal center of the membrane (Fig. 49I ). Paraphallus absent. Mesophallus dark, cylindrical, as long as distiphallus (Fig. 49I ). 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, pigmented, with inflated, truncated apex (Fig. 49I ). Ejaculatory apodeme pale brown, with fan-shaped blade and broad stalk; base wide to one side; sperm pump clear (Fig. 49H ).

Female (Fig. 49F ). Similar to male, mediotergite sometimes brownish. Wing length 1.9 mm. Postabdomen: (Fig. 49L, M ) Oviscape dark brown, setigerous (Fig. 49L ). Tergite 10 trifurcate, laterally uniting narrow pleural sclerites (Fig. 49M ). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus (Fig. 49M ). Spermathecae semi-orbicular, with truncate proximal ends (Fig. 49L ).

Variation.

The color of the lateral stripes on the scutum varied among populations, but a geographical cline was not observed. The number of tubercle-like setae in a comb of the male epandrium varied from 5 to 6 among localities.

Etymology.

The specific name (pallidus = pale, fascia = stripe) refers to the two pairs of pale brown stripes on the scutum.

Japanese name.

Kirisame-jagoke-hamoguribae.

Host plant.

Conocephalum orientalis ( Conocephalaceae ).

Mine.

Larvae construct linear mines in the thallus in early instars, later entering the midrib, and pupate in the mines (Fig. 49N-P ).

Biological notes.

The habitats of this species are stream banks and mesic slopes in warm temperate evergreen forests dominated by Castanopsis cuspidata and Quercus glauca . Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Distribution.

Japan: Honshu, Shikoku and Kyushu (Fig. 50 ).

Remarks.

This species resembles P. nigroflava , P. brunofasciata , and P. bifasciata in having two pairs of dark lateral stripes on the scutum; it is distinguished from them by the color of the stripes (pale brown in P. pallidofasciata ; black in P. nigroflava ; brown in P. brunofasciata ; inner pairs black and outer pairs pale brown in P. bifasciata . This species also resembles P. luteola in having wholly yellow body; it is distinguished from the latter by having two pairs of lateral stripes on the scutum (absent in P. luteola ), and by the number of tubercle-like setae in a comb of the male epandrium (4-5 in P. pallidofasciata ; 3-4 in P. luteola ). The locality records of P. pallidofasciata are concentrated along southern sea coasts, while those of P. luteola are scattered in higher altitudes and in northern areas.

Figures

Figure 49. Phytoliriomyza pallidofasciata sp. nov. A-E holotype male A habitus B dorsal C frontal D dorsal E posterior F paratype female (MK-AG-a 520), dorsal G-J male genitalia G whole genitalia H ejaculatory apodeme, lateral I phallic complex, lateral J epandrium, ventral K live fly L, M female postabdomen L oviscape and spermatheca M tergite 10 N-P mined thalli of Conocephalum orientalis. An arrow in O indicates an internal puparium.

Figure 50. Locality records of three Phytoliriomyza species associated with Conocephalum spp.: P. pallidofasciata, P. luteola and P. helva.