Petalolyma Scott, 1882

Liao, Yi-Chang, Burckhardt, Daniel & Yang, Man-Miao, 2024, Fig. 12. Neocaridina koreana Kubo, 1938 in Fig. 4. A in Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (28), pp. 141-149 : 2-3

Genus Petalolyma Scott, 1882

Petalolyma Scott, 1882: 459 . Type species: Psylla basalis Walker, 1858 , by original designation and monotypy.

Torulus Li, 1991: 37 , 41. Type species: Torulus sinicus Li , by original designation and monotypy. Syn. nov.

Diagnosis: Adult. Body large and robust, beset with long pubescence. Head narrower than mesothorax; inclined from longitudinal body axis at almost 90°. Vertex subrectangular, lacking anterior transverse suture separating it from the genal processes; genal processes conical, subacute, about as long as vertex along midline. Eyes large, hemispherical. Antenna 10-segmented with a single subapical rhinarium on segments 4, 6, 8 and 9; 1.3‒1.9 times as long as head width; flagellar segments sparsely beset with long setae; segment 10 with one terminal seta longer and one shorter than segment. Clypeus small, narrowly pyriform; hidden by procoxae and genal processes; rostrum short, in lateral view only tip of apical segment visible. Pronotum antero-medially curved downward and laterally backward; head posteriorly sometimes hiding pronotum medially. Dorsal outline of mesopraescutum, in lateral view, weakly or strongly curved. Mesosternum angularly concave antero-medially; basisternum indented postero-medially, raised laterally to form a tubercle on either side; katepisternum triangular, large; pleurosternal suture well-developed; precoxale forming a right angle. Legs relatively short and robust; metacoxa with spur-shaped meracanthus, not extended antero-medially; metatibia with a blunt tubercule at base, with 1+3 apical spurs, each on a slightly raised tubercle. Forewing lanceolate to obovate, usually with dark pattern; vein C+M+Cu strictly trifurcating; veins beset with conspicuous setae. Hindwing about three quarters length of forewing; costal setae ungrouped; vein M+Cu developed. Abdomen with short dorsal and long ventral setae. Male proctiger strongly bulging posteriorly, beset with setae. Paramere lamellar. Proximal segment of aedeagus slender, strongly curved in basal half; distal segment with weakly inflated, curved apical dilation. Female terminalia cuneate, relatively short. Fifth instar immature. Body weakly sclerotised, elongate, 1.5–1.9 times as long as wide. Cephalothorax on either side with an area laterally delimited by eye in anterior third and an area in posterior third densely covered in small, very slender sectasetae; anterior area also has a few scattered long simple setae. Antenna 8-segmented with an apical rhinarium on segments 4 and 6, and two on segment 8. Thoracic and abdominal tergites densely covered in small, slender sectasetae. Legs robust, 4-segmented; tibiotarsus longer than femur; tarsus has two moderately sized claws; tarsal arolium longer than claws, broadly triangular, weakly concave apico-medially, with petiole and unguitractor. Forewing pad long and slender, lacking humeral lobe; with marginal stripe of dense, small and slender sectasetae and dorsal stripe in apical third of similar sectasetae. Hindwing pad with a few marginal and a stripe of dorsal, densely spaced small, slender sectasetae. Anus ventral. Outer circumanal ring moderately large, irregularly heart-shaped, slightly wavy, consisting of a single row of elongate and narrow pores. Abdominal venter beset with long normal setae.

Distribution: Oriental Region. China ( Li 2011), India ( Mathur 1975), Japan ( Miyatake and Matsumoto 2008), Laos ( Cho et al. 2017), Philippines ( Crawford 1917), Taiwan ( Yang et al. 2013), Nepal and Sri Lanka (unpublished NHMB data).

Host plants: Ilex spp. ( Aquifoliaceae ). The immatures induce marginal fold galls on the leaves.

Mathur (1975) reported Petalolyma basalis (Walker) from India “on leaves of Quercus dilalata ” [= Quercus floribunda Lindl. ex A. Camus ] ( Fagaceae ). He did not mention immatures nor provide a description of them, suggesting that Quercus is a casual plant rather than a host. Castanopsis tibetana Hance ( Fagaceae ) is also reported as a host of P. castanopsis Li & Yang by Li and Yang (1991) based on two males, representing a casual host. The host of this species is Ilex asprella Champ. ex Benth. (see below). Similarly, we suspect that Vernicia fordii (Hemsl.) Airy-Shaw ( Euphorbiaceae ) is a casual plant of Torulus sinicus (= Petalolyma lii Liao & Burckhardt , nomen nov.), as it is based on one specimen only (Li 1991).

Comments: Petalolyma , as diagnosed here, constitutes a well circumscribed, putatively monophyletic taxon within the Triozidae . Potential synapomorphies constitute the long and slender apical dilation of the distal aedeagal segment and the distribution pattern of the very slender, small sectasetae in the immature. The phylogenetic significance of these characters is, however, difficult to evaluate without a phylogenetic framework. Petalolyma was not included in the molecular phylogenetic analysis of Percy et al. (2018) and comparable morphological studies are also lacking. To keep Torulus as a separate genus would render Petalolyma paraphyletic, as the latter would be defined by symplesiomorphies only. To prevent this, we propose the following synonymy: Petalolyma Scott, 1882 = Torulus Li, 1991 , syn. nov. We transfer Torulus sinicus to Petalolyma as Petalolyma sinica (Li, 1991) , comb. nov., which constitutes a secondary homonym of Petalolyma sinica Yang & Li, 1984 . We propose the replacement name Petalolyma lii Liao & Burckhardt , nomen nov.

Petalolyma includes in the new concept 14 previously described nominal and one new species, described here. Petalolyma hyalina (Kuwayama) is known only from the original description ( Kuwayama 1910), and the type material cannot be traced (H. Inoue, pers. comm.; see also below). Based on the forewing shape and venation, the remaining species can be assigned to six informal, not necessarily monophyletic, species groups ( Table 1). While species identification keys with illustrated descriptions are available for the Chinese and Japanese species ( Miyatake and Matsumoto 2008; Li 2011), and Mathur (1975) provided an adequate description for the Indian P. basalis , available information on the Taiwanese species is quite incomplete (Yang 1984; Fang and Yang 1986; Yang et al. 2013). Here, identification keys are provided and the taxonomy of the Taiwanese species is reviewed.