Cacopsylla (Hepatopsylla) chinensis (Yang & Li)

Luo, Xinyu, Li, Fasheng, Ma, Yanfang & Cai, Wanzhi, 2012, A revision of Chinese pear psyllids (Hemiptera: Psylloidea) associated with Pyrus ussuriensis, Zootaxa 3489, pp. 58-80 : 65-69

Cacopsylla (Hepatopsylla) chinensis (Yang & Li)

( Figs 20–32 )

Psylla chinensis Yang & Li, 1981: 37 ; Hodkinson, 1986: 325.

Cacopsylla chinensis ( Yang & Li): Li, Liu & Yang, 1993 : 9; Yang, Huang & Li, 2004: 213; Li, 2011: 872. Cacopsylla guangdongli Li, 1993: 452 . Synonymized by Li, 2011: 872.

Adult. Coloration: Summer form: General colour green to yellow. Concave area around discal foveae of vertex slightly darker. Ocelli orange. Compound eyes grey. Antenna light yellow, apices of segments IV–VIII brown, segments IX–X entirely black. Thoracic terga with orange stripes. Legs yellow. Fore wing transparent and more or less yellowish ( Fig. 28 ), veins yellow, without marking near apex of claval suture. Male and female terminalia yellow.

Winter form: Body brown, with dark pattern occupying large areas. Vertex yellow, discal foveae dark brown, concave area around discal foveae with dark brown marking that vary among individuals. Genal process brown. Antenna yellowish brown, apices of segments IV–VII dark brown, segments VIII–X entirely black. Ocelli yellow or orange. Thoracic terga brown, with dark brown stripes on mesopreascutum, and black stripes on mesoscutum. Legs brown, femora variably blackened; apical tarsal segments dark brown. Fore wing transparent and colourless, veins dark brown, C+Sc and pterostigma yellowish brown, marking near apex of claval suture dark brown and relatively small. Abdomen including male and female terminalia dark brown.

Structure: Summer form: Body glabrous. Head strongly inclined from longitudinal body axis, about as wide as mesoscutum. Vertex ( Fig. 21 ) finely sculptured with microscopic setae and scaly micro structures that are relatively large, smooth and dense. Genal processes ( Fig. 20 ) cone-shaped, moderately divergent and subacute apically, about as long as vertex along median suture, covered with long setae. Antenna slender and relatively short; terminal setae ( Fig. 26 ) of different lengths, longer one about 1.5 times as long as shorter one, and slightly shorter than antennal segment X. Metatibia with blunt basal spine, apical spurs arranged as 1+3+1. Fore wing ( Fig. 28 ) oval, widest in the middle; pterostigma relatively long, ending in the apical 2/5 of cell r1; cell cu1 near quadrate, curvature of vein Cu1a relatively strong; surface spinules present in all cells, leaving wide spinule-free stripes along veins, fields narrowing along wing margin in cells r1, r2, m1, m2 and cu1.

Male terminalia: Proctiger ( Fig. 22 ) slender and slightly curved, covered with sparse short setae. Paramere ( Figs 22, 24 ) lamellar and slender; apex tooth-shaped, slightly projected cephalad; setae present in both inner and outer surface, particularly dense and long in basal half of inner surface, and along anterior and posterior margin; uneven on outer surface, more densely spaced in posterior half. Apical dilatation ( Fig. 23 ) of aedeagus spoonshaped, with rounded tip; sclerotised end tube of ductus ejaculatorius near straight. Subgenital plate ( Fig. 22 ) with several setae that vary in length along dorsal margin, ventral surface evenly covered with short setae.

Female terminalia ( Fig. 25 ): Proctiger weakly concave dorsally, covered with setae that vary in length; laterally and apex of apical part sparsely covered with peg setae that are relatively long, gradually replaced by normal setae basally. Anus large, nearly half as long as the proctiger longitudinally. Subgenital plate covered with short setae on ventral surface, with several peg setae at subapex.

Winter form: Differing from summer form in: Body much larger than summer form. Terminal setae ( Fig. 27 ) of antenna short, the longer one about 1.5 times long as the shorter one, about half long as antennal segment X. Fore wing ( Fig. 29 ) oblong oval, widest at apical third; 4 obscure radular areas present in cells cu1, m2, m1 and r2 (the one in r2 smaller and variable in size among individuals), surface spinules reduced to small area along claval suture.

5th instar nymph. Coloration: For specimens preserved in absolute ethanol and not dissected. Body general color yellow, sclerites of mature individuals darker. Compound eyes red. Apical 2/3 of antennal segment 7 black.

Structures: Body oblong oval. Dorsal surface ( Fig. 30 ) unevenly covered with capitate setae that vary in length. Ventral surface of abdomen ( Fig. 30 ) covered with simple setae that are longer laterally. Micro spinules present on both dorsal and ventral surfaces as shown in Fig. 30 ; on dorsal surface short, lamellar and multicuspid; on ventral surface long, spinous and unicuspid. Ocular seta ( Fig. 30 ) capitate and relatively long. A long capitate seta ( Fig. 30 ) present behind compound eye near body margin on dorsal surface. Antenna ( Fig. 30 ) slender, 7-segmented, apices of segments 3 and 5 each with a rhinarium, two rhinaria on segment 7. Four pairs of capitate setae present on head anterior margin and submargin ( Fig. 30 ). A sclerite with a spiracle present on ventral surface between praecoxa and mesocoxa, and a sclerite with a spiracle present on ventral surface between mesocoxa and metacoxa ( Fig. 30 ). Fore wing pad with a row of 9–11 capitate setae that vary in length along outer margin, hind wing pad with two capitate setae at distal angle ( Fig. 30 ). Dorsal surface of mesotibia with 2 long capitate setae; dorsal surface of metatibia with 1 long and 1 short capitate setae ( Fig. 30 ). Tarsal arolium ( Fig. 32 ) petiolate and fanshaped, relatively wide apically. 2+2 lateral free sclerites ( Fig. 30 ) bearing a spiracle each present on ventral surface of abdomen. Caudal plate ( Fig. 31 ) relatively large, with a pair of spiracle on either side of circum-anal ring. Outer circum-anal ring ( Fig. 31 ) oval, with anterior margin strongly concave, posterior margin almost straight and lateral margins convex. Inner circum-anal ring ( Fig. 31 ) more or less subparallel to outer, with lateral margins more evenly curved. Ventral surface of caudal plate ( Fig. 31 ) with 2+2 simple setae right anterior to outer circumanal ring, 2 simple setae within the suture, a hemicycle row of simple setae from around the spiracles to anterior of anal suture, a series of simple setae near anterior margin and a series of simple setae near posterior margin. Abdominal margin ( Fig. 30 ) bearing 7 pairs of long and 3 pairs of short capitate setae, lacking sectasetae.

Material examined. Holotype: male, dry mounted, China, Beijing, Xiyuan, 23.v.1965, Li Fasheng.

Paratypes: China, Beijing, 8 male, 6 female, Bei’anhe, 24.v.1965, Li Fasheng; 10 male, 8 female, same data as the holotype; 1 male, Beijing Agricultural University, 23.iv.1955, Yang Chikun; 4 female, Beijing Agricultural University, 23.v.1965, Li Fasheng with light trap; 1 male, 1 female, Baijiatong, 12.v.1964, Li Fasheng; 3 female, Beijing Agricultural University, 7.vi.1974, Yang Chikun; 1 female, Mentougou, 6.vi.1960, Li Fasheng; 1 male, Beijing Agricultural University, 15.iii.1975, 1 male, Beijing Agricultural University, winter form, 13.iii.1975, Yang Chikun; 2 male, 7 female, Baijiatong, winter form, 1965–IV–8, Li Fasheng; 5 male, 8 female, Baijiatong, winter form, 8.iv.1966, Li Fasheng; 1 female, Mentougou, 7.v.1960, 1 female, Mentougou, 13.iv.1960, Li Fasheng; 2 female, Beijing Agricultural University, iii.1974, Yang Wei.

Non-paratypic specimens: China, Jinlin, 10 male, 18 female, Ji’an, 150m, 11.viii.1983, Li Fasheng; 15 male, 18 female, Liudaogou, Hunjiang, 840m, 4.viii.1983, Li Fasheng; 2 male, 5 female, Tonghua, 450m, 31.vii.1983, Li Fasheng; 2 male, 2 female, Antu, 700m, 7.vii.1993, Li Fasheng. Liaoning, 3 female, Xingcheng, 780m, without date and collector. Beijing, 20 male, 17 female, Changping, Heishanzhai, 2.ix.2010, Luo Xinyu. Nei Mongol, 15 male, 16 female, Hohhot, 28.vii.1978, Yang Chikun. Hebei, 29 male, 38 female, Zhuoxian, 1965–1966, Li Fasheng, Yang Chikun & Wu Weijun; 1 female, Jinxian, 10.v.1976, Hu Dunxiao; 32 male, 39 female, Guangtoushan, Pingquan, 1200 m, 3.vii.1986, Li Fasheng. Shanxi, 7 male, 12 female, Taigu, 800 m, 30.vii.1981, Li Fasheng; 1 male, 5 female, Xuegongling, Lishi, 1700 m, 5.viii.1981, Li Fasheng; 2 male, 1 female, Fenyang, 6.viii.1981, Yang Chikun; 2 female, Zhongtiaoshan, Qinshui, 1500 m, 14.viii.1981, Li Fasheng. Shaanxi, 4 male, 3 female, Wugong, 10.viii.1962, Li Fasheng & Yang Chikun; 4 male, 9 female, Zhenba, 1200 m, 20.vii.1985, Li Fasheng; 9 male, 15 female, Foping, 1200 m, 17.vii.1985, Li Fasheng. Ningxia, 2 male, 2 female, Lingwu, 1100 m, 1.vi.1962, Gao Zhaoning; 27 male, 39 female, Luhuatai, Yinchuan, 1111 m, 1.vii.1980, Li Fasheng & Yang Chikun; 41 male, 57 female, Longde, 2300 m, 17.vii.1980, Li Fasheng & Yang Chikun. Gansu, 14 male, 22 female, Yuzhong, 2000 m, 20.viii.1980, Li Fasheng & Yang Chikun; 50 male, 31 female, Linxia, 1900 m, 18.viii.1980, Li Fasheng & Yang Chikun; 10 male, 17 female, Ciwang, Linxia, 20.viii.2000, Han Shuqin; 9 male, 9 female, Wenxian, 800 m, 6.viii.1980, Li Fasheng; 23 male, 26 female, Dangxian, 1730 m, 10.viii.1980, Li Fasheng & Yang Chikun; 1 male, 9 female, Lanzhou, 1500 m, 19.viii.1980, Li Fasheng; 13 male, 23 female, 27.viii.1980, Gangu, 1230m, Li Fasheng. Xinjiang, Korla, Zhou Nali, without details. Hubei: 6 male, 7 female, Shizishan, Wuhan, 10.vi.1984, Yang Chikun; 6 female, Yangri, Shengnongjia, 400 m, 25.vi.1984, Yang Chikun. Anhui: 3 male, 6 female, Laoda, Xuancheng, 12.ix.1980, 12.iv.1980, 27.iv.1978, collector unknown. Shandong: 3 male, 4 female, Qingdao, without details.

Absolute ethanol preserved specimens: Beijing: Changping, Heishanzhai, 2010–IX–2, Luo Xinyu.

Nymphs: China: Beijing: 18 individuals, Kangde, 8.vi.1960, collector unknown; 23 individuals, Wenquan, 4.vii.1963, Li Fasheng.

Distribution. China: Jilin, Liaoning, Nei Mongol, Beijing, Hebei, Shanxi, Shaanxi, Gansu, Xinjiang, Ningxia, Shandong, Hubei, Anhui, Zhejiang, Guizhou, Guangdong, Taiwan.

Host plants. This species has been recorded on nearly all cultivated species and varieties of Chinese domestic Pyrus species, such as P. bretschneideri and P. pyrifolia , including the strains bred from P. ussuriensis . However, it is seldom found on varieties of P. c o m m u n i s.

Remarks. Known as Chinese pear psyllid, this species is, economically, the most important pear psyllid in China. It is widely distributed with a relatively wide host range. Its voltinism differs in different latitudes. In Beijing it has 4 generations per year ( Pan & Du 2006), in northeastern China 2–3, while south of Hebei it may have 6–7 generations ( Li et al. 1992). Like C. pyricola , this species overwinters as adults in fallen leaf-litter or on the stems of the host. The overwintering period in Beijing is from late October to mid March, and is shorter in warmer areas. The nymphs secrete small amounts of wax and honey-dew that is relatively watery. Older nymphal instars are almost entirely submerged in their own secretions.

We suspect that this species has a wider distribution than currently recorded. It probably occurs in all provinces of China where the four major series of cultivated pears are planted.

Figures

FIGURES 20 – 29. Cacopsylla (Hepatopsylla) chinensis (Yang & Li, 1981), adult. 20. Head, antennae removed; 21. microscopic structure of denoted part of vertex; 22. male terminalia, without distal aedeagus segment; 23. distal aedeagus segment; 24. inner view of paramere; 25. female terminalia, inner valvulae removed; 26. antennal segment X of summer form; 27. antennal segment X of winter form; 28. fore wing of summer form; 29. fore wing of winter form. Scale: for 20, 0.16 mm; for 21, 0.064 mm; for 22, 23 & 25, 0.2 mm; for 24, 26 & 27, 0.32 mm; for 28 & 29, 0.3 mm.

FIGURES 30 – 32. Cacopsylla (Hepatopsylla) chinensis (Yang & Li, 1981), nymph. 30. Overall view, left half shows dorsal aspect, right half shows ventral aspect; 31. ventral surface of caudal plate; 32. tarsal arolium and claws. Scale: for 17, 0.6 mm; for 18, 0.2 mm; for 19, 0.05 mm.