Trioza burckhardti Liao and Yang, 2025

Trioza burckhardti Liao and Yang sp. nov.

Figs 1–5 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5

Type material. Holotype: TAIWAN • ♂; Hsinchu Co., Jianshi, Beidelaman ; 24°44'15.7"N, 121°16'58.8"E; 1 May 2019; Y. C. Liao leg.; Helicia cochinchinensis ; NCHU, dry mounted. GoogleMaps

Paratypes: TAIWAN • 42 ♂, 25 ♀, 12 immatures; same data as for holotype GoogleMaps • 3 ♂, 3 ♀; same data as for holotype, but NMNS GoogleMaps • 3 ♂, 3 ♀; same data as for holotype, but NHMB GoogleMaps • 2 ♂, 1 ♀; Hsinchu Co., Jianshi, Beidelaman ; 24°44'15.7"N, 121°16'58.8"E; 30 Apr. 2011; C. T GoogleMaps . Tang leg.; Helicia cochinchinensis • 3 ♂, 2 ♀; Taichung City, Daxueshan forest road: 16 K; 24°14'37.3"N, 120°54'47.7"E; 8 Mar. 2012; Y. C. Liao leg.; Helicia rengetiensis GoogleMaps • 1 ♂, 1 ♀; Taichung City, Daxueshan forest road: 16K; 24°14'37.3"N, 120°54'47.7"E; 21 Feb. 2013; Y. C. Liao leg.; Helicia rengetiensis GoogleMaps • 5 immatures; Taichung City, Daxueshan forest road: 20.5K; 24°14'41.1"N, 120°55'20.0"E; 22 Jan. 2014; B. C. Lai leg.; Helicia rengetiensis GoogleMaps • 15 ♂, 18 ♀, 12 immatures; Taichung City, Daxueshan forest road: 20.5K; 24°14'41.1"N, 120°55'20.0"E; 28 Jul. 2017; Y. C. Liao leg.; Helicia rengetiensis GoogleMaps • 1 ♀, 26 immatures; Hsinchu Co., Jianshi, Beidelaman ; 24°44'15.7"N, 121°16'58.8"E; 23 Apr. 2018; Y. C. Liao leg.; Helicia cochinchinensis GoogleMaps

• 2 ♂, 4 ♀, 25 immatures; Taoyuan City, Fuxing, Dongyanshan Forest Recreation Area ; 24°49'10.9"N 121°24'40.2"E; 29 Apr. 2019; Y. C. Liao leg.; Helicia cochinchinensis GoogleMaps • 7 immatures; Hsinchu Co., Jianshi, Lidongshan ; 24°41'23.0"N 121°18'31.0"E; 29 Apr. 2019; Y. C. Liao leg.; Helicia cochinchinensis GoogleMaps • 1 immature; Xinbei City, Sanxia, The Great Roots Forestry Resort ; 24°52'24.3"N 121°24'22.5"E; 10 Dec. 2020; Y. C. Liao leg.; Helicia formosana GoogleMaps

Description. Adults ( Figs 1 View FIGURE 1 , 5A View FIGURE 5 ). Coloration. Body color yellowish brown ( Fig. 1 View FIGURE 1 ). Newly emerged individuals light green. A white stripe on dorsum of abdomen. Antennae yellow with apices of segments 4, 6 and 8 dark brown, and entire segments 9 and 10 black. Compound eyes reddish brown. Ocelli orange. Legs brown. Forewing and hindwing transparent.

Structure. Body median-sized, length from anterior head margin to tip of folded forewing 3.7–4.9 mm, female larger; covered in long fine setae. Head ( Fig. 1B, D View FIGURE 1 ) slightly narrower than thorax, inclined in a 45° angle from longitudinal body axis. Vertex ( Fig. 2A View FIGURE 2 ) 1.7–1.9 times as wide as long, moderately concave at posterior margin. Genal processes prominent ( Fig. 2A View FIGURE 2 ), 0.6–0.8 times as long as vertex along mid-line, divergent, conical, blunt at apex, pubescent. Antenna ( Fig. 2C, E View FIGURE 2 ) slender, 10-segmented, 1.7–1.9 times as long as head width, relative length of flagellar segments as 1.0: 0.4: 0.3: 0.3: 0.3: 0.3: 0.2: 0.2, with a single rhinarium on each of segments 4, 6, 8 and 9; longer, pointed terminal seta 1.1 times and shorter, truncate terminal seta 0.2 times as long as segment 10. Thorax weakly arched dorsally. Pronotum deflexed from mesothorax in a 45° angle. Legs slender. Meracanthus well developed, horn-shaped, acute at apex ( Fig. 2F View FIGURE 2 ); metatibia 1.2–1.3 times as long as head width, slightly inflated basally with small spines, with 1+2 apical spurs. Forewing ( Fig. 2B View FIGURE 2 ) 5.3–6.0 times as long as head width, 2.7–2.9 times as long as wide, widest slightly distal to the middle; wing apex subacute, lying in cell m 1 near apex of vein M 1+2; vein R+M+Cu strictly trifurcating into veins R, M and Cu; vein Rs moderately long, irregularly, concavely curved to fore margin of wing; vein M weakly curved with moderately long diverging branches; cell m 1 triangular; vein Cu 1a slightly curved; cell cu 1 same size as cell m 1; line connecting apices of veins Rs and Cu 1a proximal of bifurcation of vein M; surface spinules absent; radular spinules present along wing margin in the middle of cells m 1, m 2 and cu 1. Hindwing ( Fig. 2D View FIGURE 2 ) 0.6 times as long and 0.5 times as wide as forewing.

Male terminalia ( Fig. 3A–C View FIGURE 3 ). Proctiger tubular, in profile broadly convex posteriorly, covered in long setae except for basal third laterally ( Fig. 3A View FIGURE 3 ). Subgenital plate subglobular, with long setae laterally and ventrally. Paramere ( Fig. 3B View FIGURE 3 ) about as long as proctiger; in profile lamellar, irregularly narrowing to apex which is acute and weakly directed inwardly; inner face beset with long setae. Distal segment of aedeagus ( Fig. 3C View FIGURE 3 ) about as long as paramere, apical third inflated, spoon-shaped; sclerotized end tube of ductus ejaculatorius short, sinuous. Female terminalia ( Fig. 3D View FIGURE 3 ) cuneate, short. Proctiger with sinuate dorsal margin and pointed apex, longer than subgenital plate; with long setae in the middle and apically; circumanal ring one fourth as long as proctiger, consisting of one row of pores ( Fig. 3D View FIGURE 3 ). Subgenital plate, in profile, irregularly triangular, acute at apex; beset in long hairs laterally and ventrally. Dorsal valvulae cuneate, ventral valvulae straight lacking teeth.

Measurements (range, mean±SD) in mm ( 5 males, 5 females). Body length (including forewing) ♂ 3.72–4.14, 3.98±0.17; ♀ 4.56–4.90, 4.68±0.13. Head width ♂ 0.63–0.66, 0.65±0.01; ♀ 0.68–0.71, 0.69±0.01. Vertex width ♂ 0.38–0.39, 0.38±0.01; ♀ 0.40–0.41, 0.41±0.01 Vertex length ♂ 0.20–0.23, 0.22±0.01; ♀ 0.24–0.25, 0.24±0.01. Genal cone length ♂ 0.16–0.19, 0.17±0.01; ♀ 0.17–0.19, 0.18±0.01. Antenna length ♂ 1.08–1.24, 1.18±0.06; ♀ 1.20–1.26, 1.23±0.03. Metatibia length ♂ 0.74–0.80, 0.77±0.02; ♀ 0.85–0.90, 0.88±0.02. Forewing length ♂ 3.28– 3.58, 3.47±0.12; ♀ 3.92–4.21, 4.05±0.11. Forewing width ♂ 1.18–1.27, 1.24±0.04; ♀ 1.47–1.59, 1.51±0.05.

Fifth instar immatures ( Figs 4 View FIGURE 4 , 5B View FIGURE 5 ). Coloration. General color light green. Body ( Fig. 4A View FIGURE 4 ) form oval, 1.5–1.6 times as long as wide; sclerotized dorsally, membranous ventrally. Dorsal body surface covered in short normal setae or acute sectasetae; margin of head, forewing ( Fig. 4C View FIGURE 4 ) and hindwing pads, as well as caudal plate covered with long, very slender, acute sectasetae which are relatively densely spaced (distance between setae about 0.8–1.0 times their length). Antenna ( Fig. 4F View FIGURE 4 ) weakly curved; 8-segmented; scape and pedicel much thicker than flagellum; relative length of flagellar segments as 1.0: 0.6: 0.3: 0.5: 0.4: 1.8; with a single subapical rhinarium on each of segments 4 and 6, and two on segment 8. Legs moderately long, femur slightly shorter than tibiotarsus; tarsus with two well-developed claws, tarsal arolium ( Fig. 4B View FIGURE 4 ) longer than claws, triangular with a cleft in the anterior margin, lacking pedicel. Forewing pad 3.5 times long as broad, 2.2–2.5 times as long as antenna; humeral lobe relatively short, reaching hind margin of eye. Caudal plate broadly rounded caudally, 0.9–1.0 times as long as wide. Circumanal ring ( Fig. 4D, E View FIGURE 4 ) relatively wide, two lobes, each robust with round apex, 0.4 times as wide as caudal plate; in ventral position close to hind of caudal plate; outer ring composed of 1 row of pores.

Measurements (range, mean±SD) in mm ( 5 immatures). Body length 2.05–3.00, 2.51±0.35. Head width 0.78– 0.80, 0.79±0.01. Antenna length 0.48–0.53, 0.50±0.02. Metatibiotarsus length 0.63–0.70, 0.66±0.03. Forewing pad length 1.11–1.23, 1.18±0.05. Caudal plate length 0.95–1.45, 1.11±0.20. Caudal plate width 1.10–1.48, 1.24±0.14. Circumanal ring width 0.44 (n = 1).

Etymology. The species name derives from Dr. Daniel Burckhardt, in honor of his significant contributions to the systematics of Psylloidea.

Distribution. Taiwan.

Host plant. Helicia rengetiensis Masam. , Helicia formosana Hemsl. , Helicia cochinchinensis Lour.

Biology. This species is univoltine, with adults emerging from February to April. It usually induces leaf curling galls ( Fig. 5C, D View FIGURE 5 ) but can occasionally induce flower galls ( Fig. 5E, F View FIGURE 5 ), even on the same individual plant. The galls are semi-open, each containing multiple immatures inside. This species inhabits lowland mountainous areas, occurring in the forest understory at elevations of 600 to 1,500 m elevation.