Cecidomyiidae Newman, 1834

Family Cecidomyiidae Newman, 1834 View in CoL View at ENA Tribe Asphondyliini Enderlein, 1914 Subtribe Asphondyliina Enderlein, 1914 Genus Pseudasphondylia Monzen, 1995

Pseudasphondylia Monzen 1955: 41 View in CoL . Type species: Pseudasphondylia rokuharensis Monzen, 1955 View in CoL .

Philadelphella Kovalev 1964: 440 View in CoL . Type species. Philadelphella philadelphi Kovalev, 1964 View in CoL .

The genus is known from China, Far-East Russia, India, Japan, New Caledonia, and Taiwan, and until now comprised 14 species ( Gagné and Jaschhof 2021; Matsuda et al. 2021; Elsayed et al. 2023). A fifteenth species is described below from Taiwan on Neolitseae View in CoL species. The description, DNA, and host spectrum of the new species were provided below.

Pseudasphondylia hooki sp. n. Lin, Tokuda & Yang ( Table 2; Figs. 3–4 View Fig View Fig ) urn:lsid:zoobank.org:act:

Type materials: Holotype: ò (on slide, NCHU), TAIWAN: Taipei City, Mt. Yang-Ming National Park , gall collected on 17.ii.2011 and adult emerged on 23.ii.2011, ex. Neolitsea sericea , leg. SF Lin.

Paratypes: TAIWAN: Ex. Neolitsea acuminatissima : [ Taipei City] 4ñ, 4 pupal exuviae (on slides, NCHU), gall collected on 22.i.2013 and adult emerged on 26.i.2013, Mt. Yang-Ming National Park, leg. SF Lin; [ Nantou Co.] 4ò, 1ñ, 10 pupal exuviae (on slides, NCHU), gall collected on 23.iii.2013 and adult emerged on 25–28.iii.2013, Mt. Liying, leg. SF Lin; [ Yilan Co.] 2 pupae (on slides, NCHU), 12.ii.2009, Taiwan Beech National Trail, Mt. Taiping, leg. TC Tang. Ex. Neolitsea konishii : [ Taipei City] 4ò, 9ñ, 3 pupae, 26 pupal exuviae (on slides, NCHU), gall collected on 17.ii.2011 and adult emerged on 24–26. ii.2011, Mt. Yang-Ming National Park, leg. SF Lin; 5ò, 8ñ, 2 pupae, 6 pupal exuviae (on slide, NCHU), 11.iii.2011, Mt. Yang-Ming National Park, leg. SF Lin; 8ñ, 12 pupal exuviae (on slides, NCHU), gall collected on 22.i.2013, adult emerged on 28.i.2013, Mt. Yang-Ming National Park, leg. SF Lin. Ex. Neolitsea sericea [ Taipei City] 2ò, 6ñ, 7 pupae, 50 pupal exuviae (on slides, NCHU), same data as holotype; 1ñ, 2 pupae, 9 pupal exuviae (on slides, NCHU), gall collected on 18.iii.2011 and adult emerged on 20.iii.2011, Mt. Yang-Ming National Park, leg. SF Lin; 2 mature larvae (on slides, NCHU), 30.xii.2013, Mt. Yang-Ming National Park, leg. SF Lin; 5ò, 1 pupa (in EtOH, NCHU), 11.ii.2001, Mt. Yang-Ming National Park, leg. LH Liao, MM Yang; 10ò (in EtOH, NMNS), gall collected on 29.i.2024 and adult emerged on 4~ 5.ii.2024, Mt. Yang-Ming National Park, leg. SF Lin. Ex. Neolitsea parvigemma : [ Pingtung Co.] 8 mature larvae (six in EtOH, two on slide, NCHU), 17.ii.2017, Dahan forest rd. leg. SF Lin. Ex. Neolitsea variabillima : [ Nantou Co.] 1 mature larva (in EtOH, TFRI), 18.i.2010, Mt. Peitungyen-Nantungyen 3.4K, leg. GS Tung.

Adult: Head. Eye bridge 3– 4 facets long. Frontoclypeal setal count as in table 2. Labella hemispherical in lateral view, with setae. Palpus three-segmented ( Fig. 2A View Fig ), first segment globose, 25–30 μm long, with 2–4 setae; second 2.0 times as long as first, with 4–8 setae and third 2.2 times as long as first, with 7–10 setae. Twelve flagellomeres, the last three equal in length in male ( Fig. 2B View Fig ). Female distal flagellomeres gradually shortened, flagellomere 11 subglobular and terminal one globular ( Fig. 2C View Fig ).

Thorax: Thoracic setal and scale counts as in table 2. Legs with dense blackish scales; first tarsomeres of all legs with apicoventral spur; tarsal claws bent after midlength on all legs; pulvilli shorter than claws; empodia slightly shorter than claws on all legs ( Fig. 2D–E View Fig ). Wing 3.1–4.0 mm long, 2.0–2.4 times as long as wide in male; 3.2–3.4 mm, 2.3 times as long as wide in female. R 5 joining costa posterior to wing apex ( Fig. 2F–G View Fig ).

Male abdomen: Tergites I–VII rectangular, covered with scales on medium part, with a few lateral setae; tergites I–VI with 1–2 posterior row of setae; tergite VII with few setae on posterior part; sternites II–VII with anterior pair of lateral setae, cover with scattered setae and scales, sternites I–VI with three to four posterior row of setae; sternites VII with three to four posterior row of setae; tergite VIII covered with scattered setae and few scales.

Terminalia ( Fig. 2H View Fig ): cerci forming a pair of lobes, each lobe with a few apical setae; hypoproct bilobed, deeply separated, each lobe with two apical setae; gonostylus suboval, with two separate sclerotized teeth cover with setae; gonocoxite elongate, cover with setae dorsally and ventrally; mediobasal lobe of gonocoxite present; aedeagus laterally sclerotized in basal part, distally tapering.

Female abdomen: First through seventh tergites and second through sixth sternites as in male. Seventh sternite 0.5–0.6 mm long, protrusible part of ovipositor 1.3–1.7 mm long ( Fig. 2I View Fig ), 2.5–3.1 times as long as the length of seventh sternite.

Pupa: Body length 2.7–3.0 mm, pupal skin not pigmented except for antennal horns. Antennal horn 280–320 µm long, triangular, lateral margin without irregular serration ( Fig. 3 View Fig ); cephalic papilla with seta, 40–65 µm long; frons without horns; two pairs of facial and three pairs lateral facial papillae present; prothoracic spiracle ( Fig. 3 View Fig ) 180–210 µm long; second to sixth abdominal spiracles 50–70 µm long; second to seventh abdominal segments with 4 to 5 transverse rows of spines ( Fig. 2J View Fig ); eighth abdominal segments with 3 to 4 transverse rows of spines; eight dorsal papillae on first to the seventh abdominal segments, most outer and second inner pair papillae with seta; two dorsal papillae on eighth abdominal segment, each with seta; pleural papilla present on each side, with seta.

Mature Larva: Body color in life yellow, length 2.0– 2.3 mm. Second antennal segment short, conical; cervical papillae without seta. Sternal spatula 330–370 µm long, anteriorly with two lobes ( Fig. 3 View Fig ); four lateral papillae and a sternal papilla present on each side of all thoracic segments, each with seta; four dorsal papillae on all thoracic and first to seventh abdominal segments, two dorsal papillae on eighth abdominal segment, each with seta; pleural papilla present on each side, with seta; 2 asetose terminal papillae present; anal papillae not apparent.

Distribution: Taiwan.

Gall and Host: Monothalamus, spherical gall on the leaves of six Neolitsea species, N. acuminatissima , N. daibuensis , N. konishii , N. parvigemma , N. sericea , and N. variabillima . Gall development and morphology are shown in Liang et al. (1999) and Tung et al. (2018). A total of 1059 galls of P. hooki were examined, including 225 galls on N. acuminatissima , 62 on N. daibuensis , 98 on N. konishii , 90 on N. parvigemma , and 500 on N. variabillima . All of them occurred on the abaxial side of the host leaf ( Table 3).

Biological notes: This species is fundamentally univoltine. Adults emerge directly from galls in February and females lay eggs possibly into new buds as in P. neolitseae . Larvae soon hatch and remain inside the host tissue as the first instar until October. Liang et al. (1999) mentioned the gall started to grow from August and reached the maturation phase in October. Subsequently, larvae within the galls undergo maturation in January and pupate during middle mid- January and early February. While Takasu and Yukawa (1984) reported the occurrence of extended diapause and a semivoltine life cycle in Japanese P. neolitseae , the presence of such individuals in P. hooki remains unconfirmed

Remarks: Male terminalia and larval features, sternal spatula with two lobes and cervical and ventral papillae lacking seta, of the new species are similar to those of P. neolitseae . Nevertheless, the new species is distinguishable from P. neolitseae by the deeper insersion of larval sternal spatula ( Fig. 3 View Fig ), serrate lateral margin of the antennal horns ( Fig. 3 View Fig ) and hookliked prothoracic spiracle ( Fig. 3 View Fig ) in pupa, and the three-segmented palpus. In contrast to these features, P. neolitseae possesses sternal spatula with shallower insersion in larva, antennal horns with flat lateral margin and long prothoracic spiracle in pupa, and twosegmented palpus in adult.

Species delimitation and divergence

A total of 20 COI sequences (~658 bp) of Neolitsea -associated Pseudasphondylia species were obtained. Among them, 17 COI sequences of P. hooki were obtained from six host plants in Taiwan and three from P. neolitseae on N. sericea in Japan ( Table 1). Excluding the three outgroups, the ASAP revealed that P. neolitseae formed one entity under all asap-score modes, whereas P. hooki formed one to 11 entities with different asap-score modes. The ASAP branch nodes of the two species did not support their distinction ( P > 0.1) ( Fig. 4 View Fig ). The COI genetic distance is 0.7% within P. hooki sp. n., 0% within P. neolitseae , while 2.7% (2.5– 3.1%) between the two species. The divergence time between them was estimated at around 1.2–1.3 mya.

Molecular phylogeny

The comparison of the transition and transversion frequencies of our two dataset revealed that the 1 st codon and 1 st +2 nd codons did not reach saturation. In contrast, saturation was observed in other datasets, including those containing the 2 nd, 3rd, and all codon positions ( Fig. 5 View Fig ). Therefore, a total of 202 positions from the 1 st codon and 404 positions from the 1 st + 2 nd codons were used for further phylogenetic analysis. As a result, phylogenetic trees form both datasets shared similar topologies but some branches weakly supported in the tree reconstructed from the 1 st + 2 nd codons. In the present study, we showed the tree based on 1 st codon dataset as it most clearly illustrated the phylogenetic relationship. The phylogenetic tree supported the monophyly of Neolitsea -associated Pseudasphondylia species (bootstrap value: 90; Fig. 3 View Fig ), as well as of P. hooki lineage (bootstrap value: 79) and P. neolitseae lineage (bootstrap value: 93). In the P. hooki clade, individuals associated with N. sericea situated at the basal part and formed a paraphyletic group with respective a clade of P. hooki individuals on the other hosts (bootstrap value: 64). Then, P. hooki individuals on N. daibuensis formed a subclade (bootstrap value: 63) and situated at the most terminal part.