Acanthococcus torikurai Tanaka, 2023

Tanaka, Hirotaka & Kamitani, Satoshi, 2023, Two new species of Eriococcidae (Hemiptera: Coccomorpha) in Japan, Zootaxa 5244 (4), pp. 387-395 : 388-389

Acanthococcus torikurai Tanaka sp. nov.

Proposed Japanese common name: Tsutsuji-fukuro-kaigaramushi.

Material examined. Holotype: JAPAN: / Hokkaido, Tokoro-gun, / Kunneppu-cho , / Rhododendron sp. , / 5. vi.1990, / coll. H. Torikura: adult female mounted singly ( ELKU) . Paratypes: same data as for holotype: 7 adult females mounted singly (3 ELKU, 4 EUMJ) .

Description (n = 8)

Live adult female: not seen.

Slide-mounted adult female ( Fig. 1 ): body oval, 2.5 (2.0–2.6) mm long, 1.8 (1.2–1.8) mm wide. Antenna 7 segmented, 282–289 (253–298) µm long; segment lengths in µm: I: 55–56 (40–60), II: 37–48 (30–48), III: 50–52 (43–57), IV: 46–56 (40–58), V: 21–24 (19–26), VI: 18–20 (15–22), VII: 41 (38–43); segments III and V without flagellate setae; other segments each with a few flagellate setae; apical segment with apical setae 43–52 (43–65) µm long, also with 2 or 3 (mostly 3) sensory falcate setae, longest falcate setae 32–40 (32–45) µm long; 2 preapical segments also each with 1 sensory falcate seta; falcate setae length on segment VI, 31–30 (20–45); V, 28–29 (28–43). Frontal lobe present, 29–30 µm (25–60 µm) wide. Frontal tubercle absent. Eyes each situated on venter near margin. Anterior spiracles each 27–28 (21–29) µm in diameter; posterior spiracles each 29–30 (25–34) µm in diameter. Anal lobe well-developed, not very strong but considerably sclerotized, with 3 (2 or 3) enlarged conical setae with blunt apices on dorsal surface, ventrally with 1 or 2 (mostly 1) flagellate setae, each seta 49–54 (45–75) µm long; anal lobe with apical seta 160 (150–188) µm long.

Dorsum. Derm membranous, smooth and without nodulations; anal lobes slightly sclerotized. Enlarged conical setae of 2 sizes: (i) short small setae, each approximately 11–20 (10–25) µm long, present on all dorsal surfaces except for body margin, but distinctly sparse on abdominal segments; (ii) longer conical setae with blunt apices, each 40–53 (30–61) µm long, present in transverse rows on cephalothorax and body margin. Margins of most abdominal segments each with 2 longer enlarged conical setae; submedial and medial areas of abdominal segment VII with 5 (4 or 5) shorter enlarged conical setae and abdominal segment VIII with 0 setae. Macrotubular ducts scattered on dorsal surface, each with outer ductule 10–11 (8–11) µm wide. Microtubular ducts simple, scattered throughout dorsum, each 5–10 µm long, elongate. Anal ring situated on dorsal margin, oval, slightly sclerotized, 50 (44–58) µm wide, 62 (56–68) µm long, partly with 2 rows of pores and 8 long setae; anal ring setae each 100–136 (88–137) µm long. Cauda absent.

Venter. Derm membranous, smooth and without nodulation; anal lobes slightly sclerotized. Labium 3 segmented, joint length of 2 apical segments each about 110 (94–124) µm; basal segment with 2 pairs of setae, second segment with 2 (0–2) pairs of flagellate setae, apical segment with 3 (3–5) pairs of flagellate setae; stylet loop 2 to 3x longer than labium. Legs well developed, lengths of segments of prothoracic legs in µm: coxa, 56–61 (50–65); trochanter, 39–40 (34–50); femur, 130–132 (110–132); tibia, 88–89 (78–90); tarsus: 108–116 (101–116) and claw, 31–32 (24–32); length of tarsal digitules 50–57 (39–58); claw digitules 32–34 (18–35); length of segments of mesothoracic legs: coxa, 60–61 (53–65); trochanter, 39–40 (35–53); femur, 128–134 (102–134); tibia, 91–100 (80–100); tarsus, 111–119 (104–123) and claw, 30–32 (27–37); length of tarsal digitules 53–58 (49–58); claw digitules 38–39 (29–39); length of segments of metathoracic legs: coxa, 68–69 (57–72); trochanter, 42–43 (40–54); femur, 134–138 (105–138); tibia, 99–102 (84–102); tarsus, 120–123 (110–130) and claw, 34–37 (28–37); length of tarsal digitules 51–57 (51–60); claw digitules 29–39 (28–42); tarsal and claw digitules slightly knobbed; tarsal digitules longer than claw digitules; claw with a denticle; all coxae without spinulae. Tibia of each prothoracic leg with 5 (4–5) setae; tibia of each mesothoracic leg with 4 (3–4) setae; tibia of each metathoracic legs with 4 (2–5) setae. Multilocular disc pores each 5–6 (4–6) µm in diameter, mostly each with 5 loculi, present in relatively dense rows across abdominal segments, also a few on thoracic segments and head. Macrotubular ducts of 1 size, similar to dorsal macrotubular ducts but with outer ductules rather small and narrow; outer ductules each 6–7 µm wide, mostly present on submarginal to marginal areas. Microtubular ducts absent. A few cruciform pores present, mainly in submarginal areas of thoracic and anterior abdominal segments. A few enlarged conical setae with finely pointed apices present on marginal areas of thoracic segments and anterior abdominal segments; other setae flagellate, mainly present on medial to submedial areas of posterior body segments and on an area between antennae.

Host plants. Rhododendron sp. (Ericaceae) .

Remarks. Acanthococcus torikurai sp. nov. is similar to Ac. glanduliferus Balachowsky 1933 in having two blunt enlarged setae on each margin of each abdominal segment, only a few enlarged setae on the dorsal abdominal segments, and the enlarged setae on the dorsum tending to get larger anteriorly. However, Ac. torikurai differs from Ac. glanduliferus as follows (contrasting character states in Ac. glanduliferus in parentheses): (i) in lacking small pores on hind legs (having small pores on hind legs); (ii) in lacking spinule on surface of meso- and metacoxae (having spinules on anterior surface of meso- and metacoxae); (iii) in lacking a cauda (having a cauda); (iv) in having different sized dorsomedial setae (dorsomedial setae are all of one size); (v) in lacking capitate ventral setae (having capitate ventral setae).

Etymology. The new species is named after Mr Hidenori Torikura, the collector of the type series.

Figures

FIGURE 1. Acanthococcus torikurai Tanaka sp. nov. Adult female collected at Tokoro-gun, Hokkaido Is., Japan in 1990. 1, antenna; 2, labium; 3, ventral macrotubular duct; 4, cruciform pore; 5, ventral enlarged conical seta; 6, hind tibia, tarsus and claw; 7, multilocular disc pore; 8, anal lobes; 9, dorsal enlarged conical seta I; 10, dorsal enlarged conical seta II; 11, dorsal macrotubular duct; 12, microtubular duct. Scale bars: 200 µm for 1, 6 and 8; 100 µm for 2; 50 µm for 5 and 10; 10 µm for others.