Phytoliriomyza chichibuensis 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

21. Phytoliriomyza chichibuensis Kato sp. nov.

Fig. 42

Material examined.

Holotype: Japan: 1♂ (MK-AG-a547), Mt. Futago, Ogano, Chichibu-gun, Saitama Pref. (36.0702°N, 138.8672°E, 930 m asl), 26-III-2021 (as larva on Conocephalum purpureorubrum ), emerged on 21-IV-2021, NSMT-I-Dip 32014. Paratypes: Japan: 1♂ (MK-AG-a387), Kanna-gawa, Nakatsugawa, Chichibu, Saitama Pref., 26-III-2021 (as larva), emerged on 20-IV-2021, NSMT-I-Dip 32015; 1♂ (MK-AG-a393), Kanna-gawa, Nakatsugawa, Chichibu, Saitama Pref., 13-III-2017 (as larva, emerged on 12-IV-2017, NSMT-I-Dip 32016.

Other material.

Japan: 1♂, Mt. Futago, Ogano, Chichibu-gun, Saitama Pref., 26-III-2021 (as larva), emerged on 21-IV-2021.

Diagnosis.

A large yellow species (wing length 2.2-2.9 mm) having a pruinose dark brown scutum with an obscure oval yellow pattern extending from the mid-posterior margin to the scutellum, a black 1st flagellomere, yellow maxillary palpus, yellow halteres, and yellow legs. Male epandrium inner-laterally with a long tubercle-like seta, and inner-basally with a comb consisting of six long, fused, tubercle-like setae. Larva mines the thallus of Conocephalum purpureorubrum .

Description.

Adult male (Fig. 42A-E ).

Head: Head entirely yellow including ocellar tubercle and back of head (Fig. 42C ). Antenna porrect, first flagellomere brown, pedicel and scape brown (Fig. 42B ). Arista subbasal, pubescent. Face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus yellow, cylindrical (Fig. 42C ). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 42D ). Orbital setulae minute and erect, in a single row.

Thorax: Thorax pruinose. Scutum yellow with a black medial stripe on anterior 2/3, one pair of black suborbicular presutural patches confluent with the medial stripe, and a pair of wide black bands (i.e., fused complex of intra-alar and supra-alar stripes) on anterior 7/8, which is confluent with the presutural patches and the medial stripe (Fig. 42D ). Scutellum yellow with lateral margins brown. The yellow patch ranging from posterior scutum to scutellum oblong and ill-defined. Subscutellum yellow. Mediotergite brown, but katatergite yellow, anatergite yellow with distal brown patch (Fig. 42B ). Pleuron yellow with brown patches on propleuron centrally and on distal margins of notopleuron, anepisternum, katepisternum and meron (Fig. 42B ). Haltere yellow. Calypter margin and hairs gray. Leg segments yellow; tibia and tarsus darker. Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 42D ). Acrostichal setulae eight or nine pairs in two irregular rows. Wing: Wing length 2.4 mm, costa reaching M1 (Fig. 42A ). Length of ultimate section of vein M4 divided by penultimate section 0.87.

Abdomen: Abdomen dorsally subshiny yellow; epandrium dark brown (Fig. 42E ). Genitalia: (Fig. 42G-K ) Epandrium rounded apically; inner-lateral surface with one long tubercle-like seta; inner-anterior surface with a comb comprising six fused, long, tubercle-like setae and an irregular row of several (2-5) small tubercle-like setae immediately outward from the comb (Fig. 42J ). Surstylus rounded, directed inwards, setose apically, with one tubercle-like seta on posterior margin (Fig. 42J ). Cercus narrow, setose. Subepandrial sclerite V-shaped in a posterior view (Fig. 42J ). Hypandrium slightly sclerotized along outer margin (Fig. 42G ). Postgonite bare, goose barnacle-shaped, pointed, and cleft apically (Fig. 42I ). Phallophorus with deep incision below (Fig. 42H ), articulated with phallapodeme, fused to epiphallus (Fig. 42I ). Basiphallus with a dark anterolateral plate on left side (Fig. 42G ). Hypophallus broad, membranous, and bilaterally asymmetrical; with a dark narrow sclerite on right side; medially with a pair of fused linear sclerites (Fig. 42H-I ). Mesophallus dark, cylindrical, widest subbasally, as long as distiphallus, tapering distally (Fig. 42H, I ). Distiphallus comprising one pair of stout tubules basally parallel to each other; basal half composed of ventral dark cuneiform sclerite and weaker medial region; distal half cylindrical, dorsally pigmented; with truncated, shortly flared unpigmented apex (Fig. 42H, I ). Ejaculatory apodeme pale brown, with rounded blade and broad stalk; base wide to one side; sperm pump clear (Fig. 42K ).

Female (Fig. 42F ). Similar to male, but larger, frons wider. Wing length 2.3 mm. Postabdomen: (Fig. 42L, M ) Oviscape dark brown, setigerous (Fig. 42L ). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 42M ). Each cercus with two stout, apical, trichoid sensilla, ¼ length of cercus (Fig. 42M ). Spermathecae semi-orbicular, with truncate proximal ends (Fig. 42L ).

Etymology.

The specific name (chichibu) refers to the region where this species was found.

Japanese name.

Shungetsu-jagoke-hamoguribae.

Host plants.

Conocephalum salebrosum and C. purpureorubrum ( Conocephalaceae ).

Mine.

(Fig. 42N ) Larvae construct linear mines in the thallus in early instars, later entering the midrib, and pupate in the mines.

Biological notes.

The habitats of this species are stream banks and cliffs in temperate deciduous forests dominated by Quercus crispula . Our rearing records suggest that this species is univoltine, and that adults emerge from overwintered pupae in spring.

Distribution.

Japan: Honshu, around Chichibu mountains in the Kanto Region (Fig. 39 ).

Remarks.

This species resembles P. islandica and P. bornholmensis in yellow pattern of scutum; it is distinguished from P. islandica by the distiphallus with weaker medial region (distiphallus without weaker medial region in P. islandica ), from P. bornholmensis by the number of tubercle-like setae in a comb of the male epandrium (6 in P. chichibuensis ; 8 in P. bornholmensis ). This species also resembles P. caliginosa in yellow pattern of scutum; it is distinguished from the latter by the number of tubercle-like setae in a comb of the male epandrium (6 in P. chichibuensis ; 8-11 in P. caliginosa ) and by the color of the first flagellomere (brown in P. chichibuensis ; black in P. caliginosa ).

Figures

Figure 39. Locality records of three Phytoliriomyza species associated with Conocephalum spp.: P. luna, P. izayoi, P. chichibuensis and P. caliginosa.

Figure 42. Phytoliriomyza chichibuensis sp. nov. A-E holotype male A habitus B lateral C frontal D dorsal E posterior F live male fly G-K male genitalia G whole genitalia, ventral H, I phallic complex, ventral and lateral J epandrium, ventral K ejaculatory apodeme, lateral, L, M female postabdomen L oviscape and spermatheca M tergite 10 N mined thallus of Conocephalum sp. 2.