Pseudococcus okinawaensis Tanaka & Choi, 2025

Tanaka, Hirotaka, Choi, Jinyeong & Kamitani, Satoshi, 2025, Taxonomic review of three species of the genus Pseudococcus Westwood, 1840 (Hemiptera: Coccomorpha: Pseudococcidae) found in Okinawa Island, Japan, with description of a new species, Zootaxa 5637 (3), pp. 579-593 : 588-591

Pseudococcus okinawaensis Tanaka & Choi , sp. nov.

( Plate 1B , Figs 5 and 6 )

[Japanese common name: Monpanoki-kona-kaigaramushi]

Material examined. Holotype: Japan: / Okinawa Is., Itomon, / Nishizaki , / on Heliotropium arboreum , / 10.iii.2023, / coll. H. Tanaka and T. Uesato, / adult female mounted singly on a slide ( ELKU, HT179 ) . Paratypes: same data as for holotype, 7 adult females mounted on separate slides (3 ELKU, 4 EUMJ, HT179 ); 1 adult female mounted singly ( ELKU, DNA-extracted voucher specimen, HT179 ); Japan: / Okinawa Is., Itomon, / Nishizaki , / on Heliotropium arboreum , / 13.iii.2023, / coll. H. Tanaka, / 7 adult females mounted on separate slides (4 ELKU, 3 EUMJ, HT190 ); Japan: / Okinawa Is, Onna-son, / Tancha, / on Pandanus odoratissimus / 13.v.2021, / coll. J. Choi, / 4 adult females mounted on separate slides (2 ELKU, 2 EUMJ, 210513 JP09 ) .

Materials examined for comparison. Japan: Bonin Is. (Ogasawara Is.), Chichi-jima I., Komagari , 3 adult females on Celtis boninensis , 26.xii.1969, coll. S. Kawai, mounted on single slide with other 2 adult females and 4 immature stage females, a part of syntype of Pseudococcus ogasawaraensis Kawai, 1973 (3 KTUA) .

Description (n = 20)

Appearance in life ( Plate 1B ): Live adult females found feeding on leaves and stems of the host-plant; secreting white to pinkish powdery wax on almost all body surfaces.

Slide-mounted adult female ( Figs 5 and 6 ): Body elongate oval, 2.9 (2.0–3.9) mm long and 1.6 (0.9–2.2) mm wide; derm membranous; segmentation recognizable, but not well developed. Anal lobes clearly observable, dorsal surface of each lobe with well-sclerotized plate and ventral surface with long apical seta, 182 (120–201) µm long; anal lobe bar absent. Antenna 531–549 (453–551) µm long, with 8 segments and many flagellate setae; subapical segment with 1 fleshy seta, apical segment with 3 fleshy setae. Eyes situated on margins, not associated with discoidal pores. Legs well developed, with many flagellate setae; hind trochanter + femur 389–390 (334–415) µm long; hind tibia + tarsus 425–426 (369–447) µm long; claw 34 (28–37) µm long, without a denticle. Ratio of lengths of hind tibia + tarsus to trochanter + femur about 1.10–1.09 (1.05–1.17): 1; ratio of lengths of hind tibia to tarsus 2.94–3.05 (2.45–4.00): 1. Paired setose tarsal digitules present, subequal in length, clubbed; claw digitules minutely knobbed. Hind leg coxae usually with translucent pores on both surfaces; femora and tibiae usually with translucent pores on hind (=dorsal) surface; rarely, tarsi with translucent pores on front (= ventral) surface; and hind trochanters without translucent pores ( Fig. 6 ). Labium 130 (128–156) µm long, shorter than clypeus. Circulus present, well developed, divided by intersegmental line, located between posterior abdominal segments III and IV, 150 (57–152) µm long and 129 (54–190) µm wide. Ostioles present, each with inner edges of lips weakly sclerotized; anterior ostioles each with a total for both lips of 22–23 (14–32) trilocular pores and 4–5 (0–9) setae; each posterior ostiole with a total for both lips of 19–26 (14–31) trilocular pores and 5–7 (2–8) setae. Anal ring 100 (97–110) µm wide, bearing 6 setae, each seta 90–153 (90–180) µm long. Cerarii numbering 17 pairs. Anal lobe cerarii (C 18) present on well-sclerotized area, usually each containing 2 conical cerarian setae, each seta 28–30 (18–38) µm long and about 10–11 (8–12) µm wide at base; 7 (3–10) auxiliary setae and a concentration of trilocular pores. Penultimate cerarii (C 17) each containing 2 conical cerarian setae, 5–6 (3–7) auxiliary setae and a concentration of trilocular pores. Cerarii situated further forward generally each with 1–4 conical cerarian setae, a few auxiliary setae and a concentration of trilocular pores.

Dorsum. Setae flagellate, each 21–51 (14–55) µm long, distributed segmentally; longest setae usually present on head or posterior abdominal segments. Trilocular pores, each 2–4 µm wide, evenly distributed. Oral rim tubular ducts, each about 10–11 (8–12) µm in diameter, 19 (13–21) duct present marginal area, in longitudinal line of posterior abdominal segments and occasionally in longitudinal line of thoracic segments and rarely in submedial area of abdominal segments. Oral collar tubular ducts each about 3–4 µm in diameter, mostly wider than trilocular pores, present on marginal area of thoracic segments and head. Discoidal pores, approximately 1 µm wide, sparsely distributed, frequently associated with oral rim tubular ducts, oral collar tubular ducts and in some cerarii.

Venter . Setae relatively long and flagellate, each 20–109 (12–168) µm long; longest setae on medial area of head. Multilocular disc-pores, each 6–8 (6–10) µm wide, present on medial area of abdominal segments IV to IX. Trilocular pores, same width as those on dorsum, evenly distributed. Oral rim tubular ducts, each about 6–7 (6–8) µm in diameter, present in groups of 1–3 on margins of thoracic and abdominal segments. Oral collar tubular ducts of 3 sizes: (i) large-type ducts, each about 3–4 (3–5) µm wide, mostly wider than a trilocular pore, present on marginal and submarginal areas of entire body; (ii) small-type ducts, each about 2–3 μm in diameter, present on submarginal to medial areas of abdominal segments; and (iii) minute-type ducts, each about 1 um in diameter, mostly narrower than a trilocular pore, present on medial areas of posterior abdominal segments. Discoidal pores, same width as those on dorsum, sparsely distributed, frequently associated with orifices of oral rim tubular ducts and largest type of oral collar ducts.

Host-plants. Heliotropium arboreum ( Boraginaceae ), Pandanus odoratissimus ( Pandanaceae ).

Remarks. Pseudococcus okinawaensis Tanaka & Choi sp. nov. is similar to P. ogasawarensis Kawai, 1973 in having translucent pores on both surfaces (anterior and posterior surfaces) of hind coxae, and in sharing other general morphological features. However, the new species differs from P. ogasawarensis (contrasting character states in P. ogasawarensis in parentheses) as follows: (i) total number of dorsal discoidal pores associated with the orifices of oral collar tubular ducts and rims of oral rim tubular ducts 9–16 (total number of dorsal discoidal pores associated with the orifices of oral collar tubular ducts and rims of oral rim tubular ducts 0–4); (ii) penultimate cerarii (C 17) situated on non-sclerotized cuticle (penultimate cerarii (C 17) situated on slightly sclerotized cuticle). The species is also similar to P. gilbertensis Beardsley, 1966 in having translucent pores on both surfaces (anterior and posterior surfaces) of hind coxae, and in sharing other general morphological features. However, the new species differs from P. gilbertensis (contrasting character states in P. gilbertensis in parentheses) as follows: (i) dorsal oral collar tubular ducts mostly wider than trilocular pores (dorsal oral collar tubular ducts narrower than trilocular pores); (ii) penultimate cerarii (C 17) situated on non-sclerotized cuticle (penultimate cerarii (C 17) situated on sclerotized cuticle).

In the molecular phylogenetic tree, the three populations of P. okinawaensis clustered together into a single clade that was sister to the clade of P. cryptus ( Fig. 7 ). The host-plants of P. okinawaensis are very common and endemic to Okinawa, suggesting that the species is probably endemic to the island.

Figures

PLATE 1. Pseudococcus spp. distributed in Okinawa I. A, Pseudococcus odermatti Miller & Williams on Gymnosporia diversifolia, collected in Nago City, Okinawa I. in 2023; B, Pseudococcus okinawaensis Tanaka & Choi, sp. nov. on Pandanus odoratissimus, collected in Onna-son, Okinawa I. in 2021.

FIGURE 5. Pseudococcus okinawaensis Tanaka & Choi sp. nov. collected in Okinawa I. in 2023. A, antenna; B, ventral trilocular pore; C, ventral discoidal pores; D, ventral oral rim duct (discoidal pore associated); E, large-type ventral oral collar duct (discoidal pore associated); F, small-type ventral oral collar duct; G, minute-type ventral oral collar duct; H, posterior tibia, tarsus, claw; I, multilocular pore; J, anal lobe cerarii; K, dorsal oral rim duct; L, dorsal oral rim duct (discoidal pore attached); M, dorsal oral rim duct (discoidal pore associated); N, dorsal oral collar duct (discoidal pore associated); O, dorsal discoidal pore; P, dorsal trilocular pore. Scale bars: 200 μm for A and H; 50 μm for J; 10 μm for others.

FIGURE 6. A hind leg of Pseudococcus okinawaensis Tanaka & Choi sp. nov. collected in Okinawa I. in 2023. A, anterior (=ventral) surface; B, posterior (=dorsal) surface. Scale bars: 200 µm.

FIGURE 7. Molecular phylogeny of Pseudococcus species inferred by maximum likelihood analysis using IQ-TREE. Concatenated sequences of COI (408 bp) and 18S rRNA (646 bp) were used in this analysis. Ultrafast bootstrap values are shown at each node.