Unachionaspis tenuis ( Maskell 1897 )

Tian, Feng & Xing, Jichun, 2022, A new species of Unachionaspis MacGillivray, 1921 (Hemiptera: Coccomorpha Diaspididae) from China, Zootaxa 5124 (5), pp. 520-532 : 526-531

Unachionaspis tenuis ( Maskell 1897)

( Figs. 14–33 )

Fiorinia tenuis Maskell 1897: 242–243 .

Kuwanaspis tenuis ( Maskell 1897) ; change of combination by Lindinger 1935: 149.

Chionaspis sakaii Takahashi 1936: 2–4 , synonymized by Takahashi & Tachikawa 1956: 10.

Unachionaspis tenuis ( Maskell 1897) ; change of combination by Takahashi & Tachikawa 1956: 10; Tang 1986: 129.

Material examined. CHINA: Guizhou Province. Sample 1: Jiangkou County, Wuluo Town, N 28º 01’ 44”, E 108º 46’ 26”, 1130 m altitude, on Chimonobambusa spp. ( Poaceae : Bambusoideae ), 31.v.2021, Feng Tian leg., 7 adult f#f#. Sample 2: Duyun County, Maojian Town, N 20º 27’ 34”, E 107º 30’ 26”, 1050 m altitude, on Indocalamus spp. , 11.vii.2021, Feng Tian leg., 6 adult f#f#.

Updated description, based on Chinese material

Appearance in life. Scale cover of adult female white, 1.4–1.7 mm long, 1.3–1.5 mm wide, pocket-shaped, narrow at the front and expanded towards posterior end, to form an irregularly round or broad triangle; exuviae yellowish, situated at anterior end; margins of scale thin but dorsum thickened, margins with arc-shaped projections; without ventral scale. Exposed body of adult female pale yellow, asymmetric, generally narrow at both ends, wide in the middle, margins with irregular protrusions. Scale cover of immature male not seen.

Slide-mounted adult female (based on two samples, n=13). Body spindle-shaped, 910–1150 (979) µm long, 410–490 (432) µm wide, cephalothorax and pygidium narrow, gradually expanding posteriorly as far as middle, metathorax and abd. I widest; degree of protrusion on each side of body different, resulting in asymmetry of body. lobe (L 3); 23. Pygidial margin. Sample 1, specimen 3: 24. Enlarged L 3; 25. Pygidial margin. Sample 2, specimen 2: 26. Enlarged L 3; 27. Pygidial margin.

Cephalothorax. Antennae separated by a space nearly as half as wide as clypeus, each antenna composed of a small tubercle and 2 robust, blunt setae. Anterior spiracles each associated with 0–4 trilocular disc pores, posterior spiracles not associated with pores.

Pygidial lobes. Lobes numbering 3 pairs, each lobe tiny and pointed; most lobes each with only the apex protruding from pygidial margin. L 1 separate from each other, unilobulate; space between L 1 containing a pair of small marginal protruberances; L 2 bilobulate, each lobule only half as big as L 1; L 3 unilobulate or bilobulate, slightly smaller than L 2.

Ducts. Dorsal macroducts short and wide, scattered on abd. II– VII, numbering about 35 on each side; dorsal macroducts near pygidial margin unspecialized; marginal macroducts similar in size to dorsal macroducts, each side with 1 duct between L 1 and L 2, and 2 between L 2 and L 3. Dorsal microducts few, scattered, on or posterior to abd. II. Ventral microducts few, scattered, occasionally concentrated near each posterior spiracle.

Gland spines. Marginal gland spines long and thick, each side with 1 spine between L 1 and L 2, 2 lateral to L 2, 2 lateral to L 3 (abd. IV), and 1 or 2 on abd. V. Lateral gland spines absent from prepygidial segments.

Perivulvar pores in five groups, with 5–7 in the median group, 6–8 in each anterolateral group and 6–8 in each posterolateral group.

Distribution. China (Fujian, Guizhou, Shaanxi, Sichuan, Zhejiang), Japan (Honshu, Kyushu, Shikoku), Russia (Sakhalin Oblast), South Korea and United States (Alabama and Florida) ( García Morales et al. 2016).

Host plants. Poaceae : on species of Indocalamus , Phyllostachys , Pleioblastus and Chimonobambusa (bamboos) ( García Morales et al. 2016).

Habit. Females found on the lower leaf surfaces, at leaf bases, along the midrib, either individual or grouped close together; heavily infested leaves had wilted and developed black necrotic spots beneath and around the scale insects.

Remarks. Unachionaspis tenuis is distinguished from all other Unachionaspis species by its unique, asymmetrical body shape, scattered dorsal microducts, and by each side having 2 marginal gland spines lateral to L 2 (the other Unachionaspis species all have only 1 gland spine in this position).

Figures

FIGURES 14–20. The habit of Unachionaspis tenuis (Maskell 1897) 14–16. Environment and host of the sample studied; 17 and 18. Female scale cover; 19 and 20. Exposed live adult female.

FIGURE 21. Unachionaspis tenuis (Maskell 1897), slide-mounted adult female. Scale bar = 100 µm.

FIGURES 22–27. Unachionaspis tenuis (Maskell 1897), slide-mounted adult female. Sample 2, specimen 1: 22. Enlarged third

FIGURES 28–33. Unachionaspis tenuis (Maskell 1897), slide-mounted adult female. 28. Pygidium; 29. Antenna; 30. Anterior spiracle; 31. Posterior spiracle; 32. Pygidial margin (abd. VI–VIII); 33. Body of slide-mounted adult female.