Cyamophila hexastigma ( Horváth, 1899 )

Cyamophila hexastigma ( Horváth, 1899) View in CoL

(Japanese name: Mutsuboshi-kijirami)

( Figs 1–6 View FIGURES 1–6 , 7–10 View FIGURES 7–10 , 26, 29 View FIGURES 26–31 , 32 View FIGURES 32–34 , 35–36 View FIGURES 35–40 , 41–42 View FIGURES 41–46 )

Psylla hexastigma Horváth, 1899: 373 View in CoL . Type locality: Japan ( Hokkaidô).

Cyamophila hexastigma View in CoL : Loginova (1977: 582).

Cyamophila floribundae Cho & Burckhardt View in CoL in Cho et al. (2017: 551) View Cited Treatment , syn. nov.

Description. Adult. Colouration. General colour ( Figs 35 View FIGURES 35–40 , 41 View FIGURES 41–46 ) light yellowish green with obscure light yellowish brown markings and longitudinal stripes on thorax; in overwintered individuals ( Fig. 36 View FIGURES 35–40 ), body colour chestnut brown to dark brown in general, with many cream-yellow coloured fine markings and stripes on head and thorax. Antenna yellow; apices of segments IV–VI and most of segment VII dark brown; segments VIII–X entirely dark brown to black. Forewing membrane transparent, colourless in general but faintly yellowish along veins in the apical half of forewing in fully matured adults, with a prominent dark brown spots at the location of the radular spinules in cells m 1, m 2, and cu 1 ( Fig. 3 View FIGURES 1–6 ); veins yellow in summer adults, becoming uniformly dark brown in overwintered adults. Apical tooth of paramere black.

Structure. Head ( Fig. 1 View FIGURES 1–6 ) strongly inclined downwards, 85–90° from longitudinal body axis in profile, slightly wider than thorax. Vertex nearly half as long as wide or slightly shorter. Genal processes conical, about 0.8 times as long as vertex, slightly divergent and subacute apically. Antenna long, 2.2–2.4 times as long as head width; longer terminal seta of segment X about twice as long as shorter seta, about 0.6 times as long as segment X ( Fig. 2 View FIGURES 1–6 ).

Forewing ( Fig. 3 View FIGURES 1–6 ) oblong oval, 2.3–2.4 times as long as wide, widest at around 2/3 from the base; membrane with dense surface spinules in all cells; spinule-free bands along veins rather broad; fields of radular spinules as in Fig. 3 View FIGURES 1–6 ; pterostigma well developed, more than 1/3 of the forewing length; Rs slightly sinuate, slightly curved towards costal margin apically; M 1+2 rather strongly arched at around the basal 1/3 and nearly straight thereafter, very slightly curved towards costal margin apically; Cu 1a strongly arched around the basal 1/4 and nearly straight thereafter. Meracanthus moderate in size, subacute and slightly curved downwards apically; metatibia with prominent genual spine, with five apical sclerotised spurs arranged in 1+3+1; basal segment of metatarsus with a pair of sclerotised lateral spurs.

Male terminalia ( Fig. 4 View FIGURES 1–6 ) moderate in size. Proctiger slender, slightly curved caudad apically. Paramere stout, 0.7 times as long as proctiger, strongly constricted in the middle, strongly widened towards the tip, weakly produced cephalad at anteroapical corner, and strongly produced caudad at posteroapical corner; inner surface ( Fig. 5 View FIGURES 1–6 ) with many retrorse setae; inner apical tooth prominent, acute, and projected cephalad. Distal aedeagal segment slightly longer than paramere; apex round and thickened, strongly hooked.

Female terminalia ( Fig. 6 View FIGURES 1–6 ) rather stout. Proctiger curved and slightly sinuate at dorsal margin, slightly upturned apically, and slightly truncated at apex ( Fig. 32 View FIGURES 32–34 ). Subgenital plate with sparse setae, acute at apex.

Fifth instar immature. Body ( Fig. 42 View FIGURES 41–46 ) light green, gently swollen dorsally. Antenna slender, 2.1–2.2 times as long as forewing pad, seven-segmented, with one apical rhinarium each on segments III and V, and two on the middle of segment VII, with rather long capitate setae on the middle of segment III and apices of segments III–V ( Fig. 26 View FIGURES 26–31 ). Forewing pad oblong oval; outer margin with 8–9 long capitate setae and short simple setae present in between ( Fig. 29 View FIGURES 26–31 ). Hindwing pad with two long capitate setae apically. Legs long, hairy, with many short simple setae and long capitate setae. Abdomen rounded apically, with many long capitate setae dorsally and many long simple setae ventrally. Caudal plate with many long capitate setae on dorsum and margin, with 4+4 truncated sectasetae on posterior margin. Anus located on ventral side. Outer circumanal pore ring relatively small, heart-shaped, strongly curved in front, comprising a single row of elongated pores. Inner circumanal pore ring comprising a single row of small elongated pores.

Measurements (in mm): Adult ( n = 5 males, 5 females): BL: 3.13–3.80; WL: 2.59–3.15; WW: 1.06–1.35; AL: 1.90–2.33; HW: 0.82–0.96; VW: 0.46–0.58; VL: 0.22–0.27; GL: 0.18–0.23; MP: 0.36–0.43; PL: 0.27–0.31; FP: 0.68–0.83. Fifth instar immature ( n = 5): BL: 2.28–2.60; BW: 1.23–1.50; AL: 1.38–1.63; WPL: 0.65–0.78; and CRW: 0.09–0.10.

Material examined. Hokkaidô: 5 males, 3 females, 2 immatures, Sapporo-shi, Minami-ku, Jôzankei , 300 m, 9.vii.2001, on Maackia amurensis, H. Inoue (dry- and slide-mounted; HIC) ; 13 males, 12 females, Sapporo-shi, Minami-ku, Jôzankei , Jôzankei Dam , 42.982º N, 141.159º E, 300 m, 19–20.vii.2012, on M. amurensis, H. Inoue (dry- and slide-mounted; HIC) GoogleMaps ; 18 males, 24 females, same data, 12.vi.2013 (dry- and slide-mounted; HIC) GoogleMaps ; 9 males, 8 females, 23 immatures, Kamikawa-gun, Shimizu-chô, Haobi , 42.957º N, 142.905º E, 190 m, 30.vi.2015, on M. amurensis, H. Inoue (dry- and slide-mounted, 99.5% and 70% ethanol; HIC) GoogleMaps ; 3 males, 1 females, Sarugun, Hidaka-chô, Chiroro-rindô , 2.vii.1998, N. Takahashi (dry-mounted; HIC) ; 1 female, Akan-gun, Akan-chô, Meakan-dake , 29.vi.1998, N. Takahashi (dry-mounted; HIC) ; Honshû : 8 males, 8 females, 4 immatures, Aomori-ken, Sannohe-gun, Shingô-mura , Herai , Kosaka , 40.444º N, 141.131º E, 170 m, 2.vii.2015, on M. amurensis, H. Inoue (dry- and slide-mounted, 99.5% ethanol; HIC) GoogleMaps ; 3 males, 5 females, Aomori-ken, Sannohe-gun, Shingô-mura , Herai , Sawaguchi , 40.454º N, 141.149º E, 160 m, 2.vii.2015, on M. amurensis, H. Inoue (dry- and slide-mounted; HIC) GoogleMaps ; Kyûshû : 2 females, Fukuoka-ken, Miyako-gun, Miyako-machi , Saigawahobashira , near Notôge , 33.502º N, 130.970º E, 750–930 m, 9.vi.2014, H. Inoue (slide-mounted; HIC) GoogleMaps ; 19 males, 26 females, 10 immatures, Nagasakiken, Unzen-shi, Obama-chô , Unzen , Ikenohara , 32.745º N, 130.270º E, 750 m, 27.v.2010, on Maackia floribunda, H. Inoue (dry- and slide-mounted; HIC) GoogleMaps ; 136 males, 140 females, 4 immatures, same data, 4.vi.2010 (dry- and slide-mounted, 99.5% ethanol; HIC) GoogleMaps ; 2 males, 5 females, same data, 14.iv.2013 (dry-mounted; HIC) GoogleMaps ; 38 males, 50 females, same data, 13.vi.2014 (dry-mounted, 99.5% ethanol; HIC) GoogleMaps .

Distribution. Japan ( Hokkaidô, Honshû, Shikoku, Kyûshû, Tsushima); China ( Beijing, Jilin, Liaoning, Shanxi), South Korea, Russian Far East (Khabarovsk Territory, Primorsky Territory) ( Wu 1932, as P. hexastigma ; Sasaki 1954, as P. hexastigma ; Miyatake 1963, as P. hexastigma ; Kuwayama & Miyatake 1971, as P. hexastigma ; Miyatake 1976, as P. hexastigma ; Park et al. 1979, as P. hexastigma ; Konovalova 1988; Li 2011; Cho et al. 2017, as C. floribundae ; Kwon & Kwon 2020).

Host plant. Maackia amurensis Rupr. ( Miyatake 1976) ; Maackia floribunda (Miq.) Takeda ( Fabales : Fabaceae ) (new host plant record). These host plants were confirmed by the presence of immatures.

Styphnolobium japonicum (= Sophora japonica ) ( Fabaceae ) recorded by Kwon (1983) is the host for Cyamophila willieti ( Cho et al. 2022) . Kuwayama (1932) referred to Hydrangea ( Cornales : Hydrangeaceae ) as follows: ‘In Hokkaidô, adults of Psylla hexastigma are abundant on Saxifragaceae plants, such as Hydrangea paniculata and Hydrangea serrata , around August. This species likely feeds on these plants’; however, these plants are not hosts on which the immatures develop. Hydrangea has been cited as a host for this psyllid species in subsequent studies, such as in Sasaki (1954), Miyatake (1963), Klimaszewski (1973), Kwon (1983), and Kwon & Kwon (2020), and is therefore formally eliminated here as the host of C. hexastigma .

Biology. Univoltine. Adults emerge from late May (Kyûshû in southwest Japan) to early July ( Hokkaidô in northern Japan) and leave the host plant within a short period. Dispersed adults are thought to stay on the evergreen shelter plants until spring.

Comments. Cyamophila floribundae Cho & Burckhardt , which feeds on Maackia floribunda , was described from Jeju Island, in the southernmost part of South Korea ( Cho et al. 2017). In my field survey, a Cyamophila population feeding on M. floribunda was confirmed from Kyûshû, Japan; this population cannot be distinguished from C. hexastigma populations feeding on M. amurensis from Hokkaidô, from which this psyllid species was originally described, through morphology as well as DNA barcoding ( Fig. 48 View FIGURE 48 ). According to Cho et al. (2017), C. floribundae differs from C. hexastigma in the following aspects: 1) denser surface spinules of forewing membrane; 2) slightly widened parameres towards the apex; and 3) host plant. However, 1) some variation was observed in the density of the forewing surface spinules in C. hexastigma , ranging from sparse ( Figs 7, 9 View FIGURES 7–10 ) to dense ( Figs 8, 10 View FIGURES 7–10 ), even within the same locality, although the spinules in M. floribunda -feeders tended to be somewhat denser. 2) No stable morphological differences were observed in paramere between the populations of different host plants. These slight differences were likely within the range of intraspecific variation. 3) Notably, Japanese C. hexastigma also feeds on M. floribunda , implying that these two nominal psyllid species cannot be distinguished from each other by their host plants. Additionally, for the Korean C. hexastigma and C. floribundae molecular data on the GenBank database used in the analysis of Cho et al. (2019), no divergence was observed in the 575 bp of the COI-tRNAleu- COII region, and only 1.45% ( p -distance) or 1.46% (K2P distance) divergence was observed in>690 bp of the mitochondrial 12S and 16S ribosomal RNA data. Therefore, I conclude that these two taxa are conspecific and can be synonymised as Cyamophila hexastigma ( Horváth, 1899) = Cyamophila floribundae Cho & Burckhardt, 2017 , syn. nov.