Phytoliriomyza wiesnerellae 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

18. Phytoliriomyza wiesnerellae Kato sp. nov.

Fig. 35 , 36

Material examined.

Holotype: Japan: 1♂ (MK-AG-a400), Sendan-todoro, Izumi, Yatsushiro, Kumamoto Pref., 10-IV-2021 (as larva on Wiesnerella denudata ), emerged on 8-V-2021, NSMT-I-Dip 31992. Paratypes: Japan: 1♀ (MK-AG-a342), same data as holotype, NSMT-I-Dip 31993; 2♂1♀ (MK-AG-a303, a489, a464), Mt. Osuzu, Tsuno, Miyazaki Pref., 10-IV-2021 (as larva), emerged on 2-13-V-2021, NSMT-I-Dip 31994-31996.

Other material.

Japan: 1♂1♀, Sendan-todoro, Izumi, Yatsushiro, Kumamoto Pref. (32.5215°N, 130.888517°E, 710 m asl), 10-IV-2021 (as larva), emerged on 8-10-V-2021; 1♂, Itsuki, Yatsushiro, Kumamoto Pref., 23-III-2015 (as larva), emerged on 3-V-2015; 2♂5♀, Mt. Osuzu, Tsuno, Miyazaki Pref., 10-IV-2021 (as larva), emerged on 2-14-V-2021.

Diagnosis.

A large dark species (wing length 2.0-2.3 mm) having subshiny dark gray scutum, yellow scutellum, black 1st flagellomere, dark maxillary palpus, gray halteres, and dark brown legs. Male epandrium inner-basally with a protruding, plate-like arm bearing one strong, tubercle-like seta apically. Larva mines the thallus of Wiesnerella denudata .

Description.

Adult male (Fig. 35A-D ).

Head: Head yellow; ocellar tubercle dark brown; front-orbital plate brown; back of head dark brown above foramen (Fig. 35C ). Antenna porrect, first flagellomere black, pedicel dark brown and scape brown (Fig. 35B ). Arista subbasal, pubescent. Face, gena, parafacial and postgena yellow. Proboscis normal, yellow; palpus brown, clubbed (Fig. 35C ). Chaetotaxy: Front orbitals three pairs; one ori directed inward; two ors directed upward (Fig. 35B ). Orbital setulae minute and erect, in a single row.

Thorax: Thorax subshiny. Scutum dark brown, with marginal inflated yellow band adjoining scutellum (Fig. 35D ). Scutellum yellow with lateral corner brown. Subscutellum yellow with narrow brown area along posterior margin. Mediotergite brown, katatergite yellow and anatergite yellow with lower brown patch (Fig. 35B ). Pleuron yellow with small pale brown patches on central propleuron and lower anepisternum, and with distinct brown patches on lower katepisternum and lower meron (Fig. 35C ). Haltere brown with yellow stalk. Calypter margin and hairs gray. Leg segments entirely dark brown (Fig. 35A ). Chaetotaxy: Scutum with 1+3 dorsocentrals, shortened anteriorly (Fig. 35D ). Acrostichal setulae seven pairs in two irregular rows. Wing: Wing length 2.0 mm, costa reaching M1 (Fig. 35A ). Length of ultimate section of vein M4 divided by penultimate section 0.83.

Abdomen: Abdomen dorsally subshiny yellow; epandrium dark brown (Fig. 35B ). Genitalia: (Fig. 35F-J ) Epandrium rounded apically, but angled dorso-posteriorly in a lateral view; inner-posterior margin with two tubercle-like setae on protruding arm; inner basal margin with a protruding, plate-like arm, which bears one strong tubercle-like seta apically (Fig. 35G, I ). Surstylus rounded, directed inwards, setose on anterior margin; basally with two tubercle-like setae (Fig. 35I ). Cercus narrow, setose. Subepandrial sclerite with one pair of plate-like arms (Fig. 35I ). Hypandrium sclerotized (Fig. 35F ). Postgonite bare and broadly rounded apically (Fig. 35H ). Phallophorus with deep incision below (Fig. 35F ), articulated with phallapodeme, fused to epiphallus (Fig. 35H ). Basiphallus dorsolaterally sclerotized, with distal margin pigmented (Fig. 35H ). Hypophallus broad and membranous; with one pair of pale narrow plate-like sclerites; medially with a pair of narrow, fused, ventrally incurved sclerites (Fig. 35H ). Mesophallus dark, cylindrical, widest basally, ¾ length of distiphallus, tapering toward distiphallus (Fig. 35H ). Distiphallus comprising one pair of stout tubules basally parallel to each other; basal 1/3 ventrally pigmented; medial 1/3 unpigmented; distal 1/3 pigmented with truncated, unpigmented apex (Fig. 35H ). Ejaculatory apodeme dark, fan-shaped, with short broad stalk; base bulbous; sperm pump clear (Fig. 35J ).

Female (Fig. 35F ). Similar to male, but larger, frons narrower, yellowish brown, abdomen darker. Wing length 2.3 mm. Postabdomen: (Fig. 36A, B ) Oviscape dark brown, setigerous (Fig. 36A ). Tergite 10 cruciform, laterally uniting narrow pleural sclerites (Fig. 36B ). Each cercus with two stout, apical, trichoid sensilla, 1/3 length of cercus (Fig. 36B ). Spermathecae subspheroidal, with truncate proximal ends (Fig. 36A ).

Etymology.

The specific name refers to the host plant genus, Wiesnerella .

Japanese name.

Azumazenigoke-hamoguribae.

Host plant.

Wiesnerella denudata ( Wiesnerellaceae ).

Mine.

Larvae construct linear mines in the thallus in early instars, later expanding their mines, and pupate in the mines (Fig. 36C, E, F ). It is difficult to find the mines, because older larvae often mine in the lower layer of the thallus, so that the mines are often not externally visible.

Biological notes.

The habitats of this species are mesic slopes in warm temperate evergreen forests. Our rearing records suggest that it is univoltine, with adults emerging from overwintered pupae in spring.

Distribution.

Japan: Kyushu (Fig. 31 ).

Remarks.

This species is superficially very similar to P. dumortierae in coloration of the head, thorax, abdomen, and legs, but is distinguished from the latter by the largely yellowish pleuron (pleuron yellow only in upper half in P. dumortierae ). The anteroposteriorly flattened head and the absence of a comb of tubercle-like setae in the male epandrium of this species suggest that this is not closely related the other liverwort-associated species.

Species associated with Conocephalum

Figures

Figure 31. Locality records of three Phytoliriomyza species associated with Reboulia and Wiesnerella spp.: P. falcata, P. aratriformis, P. rebouliae and P. wiesnerellae.

Figure 35. Phytoliriomyza wiesnerellae sp. nov. A-D holotype male A habitus B lateral C frontal D dorsal E paratype female (MK-AG-a 342), posterior F-J male genitalia F whole genitalia, ventral G epandrium, lateral H phallic complex, lateral I epandrium, ventral J ejaculatory apodeme, lateral.

Figure 36. Female morphology and larval ecology of Phytoliriomyza wiesnerellae sp. nov. A, B female postabdomen A oviscape and spermatheca, B tergite 10 C, E, F mined thalli of Wiesnerella denudata (C at Mt. Nokeeboshi E, F at type locality) D habitat at Mt. Osuzu. An arrow in F indicates an internal puparium.