Pulvinaria aurantii Cockerell, 1896

Tanaka, Hirotaka & Kamitani, Satoshi, 2021, Redescriptions of six Japanese species of the genus Pulvinaria (Hemiptera: Coccomorpha: Coccidae) with four new synonymies, Zootaxa 5071 (1), pp. 51-75 : 52-56

Pulvinaria aurantii Cockerell, 1896

( Figs 1–3 )

[Japanese name: Mikan-wata-kaigaramushi]

Pulvinaria aurantii Cockerell 1896: 19 ; Takahashi 1955: 150; Kawai 1972: 14; Kawai 1980: 152; Ben-Dov 1993: 251.

Lecanium notatum Maskell 1898: 243 .

Coccus notatus ( Maskell, 1898) ; Fernald 1903: 173.

Pulvinaria ornata Froggatt 1921: 427 (nec. Hempel 1912: 61), syn. nov.

Chloropulvinaria aurantii ( Cockerell, 1896) ; Borchsenius 1952: 300; Kawai 2003; 556, 826, 878.

Pulvinaria decorata Borchsenius 1957: 228 ; Qin & Gullan 1992: 112; Cao & Feng 2020: 230 ; replacement name for P. ornata Froggatt, 1921 (nec. Hempel 1912), syn. nov.

Material examined. JAPAN, all samples collected by H. Tanaka: Chiba Prefecture, Matsudo-shi, Matsudo , Chiba Univ. , on Pittosporum tobira , 1.v.2000, 8 adult females mounted singly (4 ELKU, 4 EUMJ) ; Chiba Prefecture, Matsudo-shi, Matsudo , Chiba Univ. , on Nerium oleander , 14.v.2004, 4 adult females mounted singly (2 ELKU, 2 EUMJ) ; Chiba Prefecture, Matsudo-shi, Sendabori, Forest and Park of 21C., on Citrus aurantium , 11.v.2004, 2 adult females mounted singly (1 ELKU, 1 EUMJ) ; Fukuoka Prefecture, Kurume-shi, Zendouji-cho , on Fatsia japonica , 15.iv.2021, 3 adult females mounted singly (2 ELKU, 1 EUMJ) ; Shimane Prefecture, Izumo-shi, Sono-cho, Shinjiko Green Park , on Pittosporum tobira , 25.iv.2021, 4 adult females mounted singly (2 ELKU, 2 EUMJ) .

Redescription. Live appearance: Body of adult female elongate oval, usually flat; dorsum brown with yellowish white oval area with dark brown or black longitudinal midline, without visible wax before oviposition ( Fig. 1 ), but with a small amount of granular or filamentous wax produced on dorsum during oviposition period; ovisac short, about 1–2 times as long as body; posterior part of body uplifted strongly by ovisac.

Slide-mounted adult female (n=21). Body elongate oval, 2.2–4.5 mm long, 1.2–2.5 mm wide, margin with distinct and relatively deep indentation at each stigmatic cleft; anal cleft approximately 1/5–1/7 times body length.

Dorsum. Derm membranous; dermal areolations well developed, forming a distinct polygonal pattern. Dorsal setae spiniform, frequent, scattered throughout dorsum, each 5–9 µm long with a well-developed basal socket. Preopercular pores each oval to circular, 2–5 µm in diameter, barely sclerotised, often difficult to see and count, numbering 4–54 anterior to anal plates. Tubular ducts and microducts frequent throughout, each situated within an areolation ( Fig. 2 DA); tubular ducts visibly more numerous than microducts, ratio of numbers of tubular ducts to that of microducts about 1.7: 1. Dorsal submarginal tubercles of normal convex type, numbering 1–7 between anterior stigmatic clefts, each side with 0–3 between anterior and posterior stigmatic clefts, and 1–6 between posterior stigmatic cleft and anal cleft. Anal plates together quadrate; each plate 140–166 µm long, 60–90 µm wide, with a well-developed supporting bar, slightly convex posterolateral margin, and 4 or 5 (usually 4) apical setae. Ano-genital fold with 1–3 pairs of setae along anterior margin and 2 or 3 pairs laterally. Anal ring bearing 5–7 (mostly 6) setae. Eyespots present in submarginal area.

Margin. Marginal setae with well-developed basal sockets and with tips fimbriate, frayed, spatulate, split, or simply pointed; each seta 12–91 µm long, each side with 14–29 setae between anterior and posterior stigmatic clefts. Stigmatic clefts distinct and rather deep, each with 0–4 (usually 3) stigmatic spines, median spine longest, 38–76 µm long, approximately 3–5 times longer than a lateral spine.

Venter. Derm membranous. Multilocular pores each 4–9 µm wide, with 4–8 (mostly 7) loculi, present around genital opening and on medial areas of preceding 3 or 4 abdominal segments; a small group also present lateral to each metacoxa and occasionally lateral to each mesocoxa. Spiracular disc pores each 3–5 µm wide, mostly each with 5 loculi, present in rather broad bands, 1–5 pores wide, between margin and each spiracle; anterior bands each containing 20–53 pores, posterior bands each with 25–75 pores. Microducts scattered throughout venter. Tubular ducts of 3 types: type I each with a large outer ductule (about 2–4 µm wide and 8–12 µm long), a stout inner ductule (about 2–3 µm wide and 10–16 µm long) and a well-developed flower-shaped terminal gland, present in posterior medial area of head, medial areas of all thoracic segments and anterior abdominal segments, also in inner submarginal area extending from near anterior abdominal segments to area between antennae; type II tubular ducts, each with a small outer ductule (2–3 µm wide and 6–12 µm long) ending in a shallow cup-shaped invagination and leading to a narrower inner ductule (<1 µm wide and 7–19 µm long) with a well-developed terminal gland, mostly occurring in medial areas of posterior abdominal segments and inner submarginal area of head, thoracic and abdominal segments; and type III ducts similar to type II, but each with a short, filamentous inner ductule (<1 µm wide and 1–5 µm long) and a minute terminal gland, intermixed with type I and type II ducts in inner submarginal areas of head, thorax and abdomen and in a broad submarginal band on head, thorax and abdomen, forming an almost complete submarginal ring, but ducts on head apex scarce or absent. Posteriormost 3 abdominal segments each with 1 pair of long ventral setae on medial area. With 3 or 4 pairs of long setae present between antennae, 1–3 pairs of long setae on area mesad of each procoxa, and occasionally 0 or 1 pair of long setae on medial area of thoracic and anterior abdominal segments; other setae short and fine, distributed throughout venter. Spiracles normal for the genus, but each surrounded by a weak and usually faintly sclerotised spiracular plate; peritreme widths: each anterior spiracle 42–58 µm, each posterior spiracle 48–72 µm. Legs well developed, each with a completely articulated tibio-tarsal joint and an articulatory sclerosis; claw without a denticle; both claw digitules rather broad and slightly shorter than thin tarsal digitules. Hind trochanter + femur 238–314 µm long, hind tibia 165–240 µm long, and hind tarsus 92–126 µm long. Antennae each 6–9 (mostly 8) segmented, 340–508 µm long. Labium 54–75 µm long, 95–130 µm wide.

Host plants in Japan. Apocynaceae : Nerium oleander ( Takahashi 1955 as Nerium, Tanaka & Amano 2006 as N. indicum ), Aquifoliaceae : Ilex rotunda ( Kawai 1980) , Araliaceae : Fatsia japonica ( Kawai 1972, 1980, Takahasi 1955), Hedera rhombea ( Kawai 1980, 2003, Takahashi 1955), Celastraceae : Microtropis japonica ( Kawai 1980) , Ebenaceae : Diospyros kaki ( Takahashi 1955) , Hydrangeaceae : Hydrangea macrophylla (Tanaka & Amano 2006) , Pittosporaceae : Pittosporum tobira ( Kawai 1972, 1980, 2003, Takahashi 1955), Rutaceae : Citrus spp. ( Kawai 1972, 1980, 2003, Kuwana 1902, 1917, Takahashi 1955 as Citrus ), Ternstroemiaceae : Cleyera japonica ( Kuwana 1902 as Eurya ochanacea ), Eurya japonica (Tanaka & Amano 2006) , and Theaceae : Camellia sinensis ( Kuwana 1902) .

Remarks. Pulvinaria aurantii is very similar to P. polygonata Cockerell, 1905 , sharing the following characteristics: (i) eyespots located in the submarginal area of the dorsum; (ii) multilocular pores mostly each with seven loculi, and (iii) have a similar distribution pattern of type III ventral tubular ducts. However, P. aurantii differs from P. polygonata as follows (character states of P. polygonata in brackets): (i) possessing mostly three stigmatic spines per cleft (usually more than three stigmatic spines); and (ii) a lighter body colour during the pre-oviposition period (relatively dark greyish brown body colour at this stage). It is also similar to P. psidii Maskell, 1893 in having fimbriate marginal setae, eyespots located in the submarginal area of the dorsum, and the presence of a sclerotised plate around each spiracle. However, P. aurantii differs from P. psidii as follows (character states of P. psidii in brackets): (i) each multilocular pore usually with seven loculi (each mostly with 10 loculi); and (ii) an undivided supporting bar underneath each anal plate (the bar is bifurcate). Important diagnostic morphological character states for P. aurantii and a comparison with the type species of the genus, P. vitis , are summarised in Table 1 . Pulvinaria aurantii can be separated from other Pulvinaria species described in this study as well as P. vitis by possessing dorsal tubular ducts and dorsal submarginal tubercles, the condition of the dermal areolation, the location of the eyespots, body shape, the distributions of multilocular pores and type III ventral tubular ducts, and the number of loculi in each multilocular pore.

The morphology of adult female P. aurantii , redescribed here, agrees well with the redescription by Takahashi (1955) except as follows (character states of Takahashi’s redescription in parenthesis): (i) marginal setae between anterior stigmatic furrow and posterior stigmatic furrow on each side numbering 14–29 (23–28); (ii) spiracular disc pores between each spiracle and stigmatic cleft numbering 20–53 (over 50 in each band); (iii) preopercular pores numbering 4–54 (referred to as dorsal minute median pores, over 50, sometimes about 70 in each individual); (iv) marginal setae each 12–91 μm long (23–50 μm); and (v) body 2.2–4.5 mm long and 1.2–2.5 mm wide (2.8–3.75 mm long and 1.6–3.5 mm wide). These morphological discrepancies are probably due to intraspecific morphological variation or the quality of the microscopes used.

In addition, we found that P. aurantii and an Australian species, P. decorata Borchsenius, 1957 (= P. ornata Froggatt, 1921 (nec Hempel, 1912)) show the same morphology (P.J. Gullan, the Australian National University, Acton, A.C.T., Australia, pers. comm.) and can therefore be considered as the same species. Thus, we propose P. decorata syn. nov. and P. ornata Froggatt, 1921 syn. nov. as new junior synonyms of P. aurantii . In their taxonomic work on Chinese Pulvinaria species , Cao & Feng (2020) considered P. aurantii and P. decorata to be distinct species. According to their morphological comparison table ( Cao & Feng 2020, Table 3), P. aurantii differs from P. decorata in having (i) eight anal ring setae ( P. decorata has six); (ii) in lacking a spiracular sclerotic plate and marginal setae with expanded paliform tips (mature adult female has spiracles with sclerotic plates and some marginal setae with paliform tips); and (iii) in possessing a small and sparse dermal areolation that does not form a reticulated pattern ( P. decorata has numerous large areolations that form a reticulated pattern). However, the Japanese specimens of P. aurantii examined in this study actually have 5–7 (mostly 6) anal ring setae, thin and faint but observable spiracular sclerotic plates, some marginal setae with expanded paliform tips, and dense dermal areolations forming a reticulated pattern. Furthermore, at least one syntype specimen of P. aurantti deposited in the Systematic Entomology Laboratory of the United States Department of Agriculture also has six anal ring setae ( Fig 3a ), a thin and faint but observable spiracular sclerotic plate ( Fig 3b ), and large dorsal dermal areolations forming a reticulated pattern ( Fig. 3c ) (S. Schneider, United States Department of Agriculture—Agricultural Research Service, Beltsville, Maryland, U.S.A., pers. comm.). In these circumstances, we do not agree with the opinion of Cao & Feng (2020) that P. aurantii and P. decorata should be regarded as separate and distinct species. It is possible that the species currently considered to be P. aurantii in China may be different from true P. aurantii . This synonymy of P. decorata with P. aurantii is probably evidence that the worldwide invasion by exotic soft-scale species to foreign countries had already occurred by the early twentieth century.

Figures

FIGURE 1. Adult females of Pulvinaria aurantii Cockerell, 1896, on a leaf of Pittosporum tobira.

FIGURE 2. Pulvinaria aurantii Cockerell, 1896, adult female collected from Kyushu Island in 2021. ANT, antenna; AP, anal plate; DA, dermal areolation; DMD, dorsal microduct; DS, dorsal seta; DT, dorsal tubercle; DTD, dorsal tubular duct; LG, leg; MP, multilocular pores; MS, marginal setae; POP, preopercular pores; SDP, spiracular disc pore; SSP, stigmatic spines; VMD, ventral microduct; VTD, ventral tubular ducts, types I to III. Scale bars: 100µm for ANT, AP, DA and LG; 50 μm for SSP and MS; 10 μm for all other features.

FIGURE 3. Partial microscopic photographs of a syntype adult female of Pulvinaria aurantii Cockerell, 1896, deposited in the Systematic Entomology Laboratory, USDA: a. anal plates and anal ring setae; b. a thin and faint but discernible sclerotic plate around a spiracle, indicated by short arrow heads; c. dorsal dermal areolation forming a reticulated pattern; d. syntype slide of P. aurantii (Photos by Scott A. Schneider).