Leucaspis trilobata Henderson

Henderson, Rosa C., Sultan, Amir & Robertson, Alastair W., 2010, Scale insect fauna (Hemiptera: Sternorrhyncha: Coccoidea) of New Zealand’s pygmy mistletoes (Korthalsella: Viscaceae) with description of three new species: Leucaspis albotecta, L. trilobata (Diaspididae) and Eriococcus korthalsellae (Eriococcidae), Zootaxa 2644, pp. 1-24 : 10-14

Leucaspis trilobata Henderson sp. nov.

Figs 1 D, 5–7

Unmounted material. Pupillarial; exuviae terminal, pupillarium light brown with a white waxy coating; adult females membranous; male covers white tinged with golden-white, with dark terminal exuviae.

Adult female ( Fig. 5 ), measurements taken from 12 specimens.

Mounted material. Body length 1.52–2 mm, width 0.58–0.8 mm measured on pupillaria. Body shape elongate when young, shortened and roundly oval with shrunken abdomen when mature, derm membranous except for pygidial sclerotisation in patches and around anal opening, and with a ventral median longitudinal band of crenulae (curved short lines of microtrichia) between mouthparts and abdominal segment III. Pygidium broadly rounded, with 2 to 3 pairs of lobes on margin, each lobe teardrop-shaped, smooth and rounded distally, about 12 μm long and 6 μm wide including basal sclerotisation; plates extending well beyond lobes, tapering to a point, slightly fringed on each side; 2 to 3 plates in each space between lobes, variable with varying lobe positions, and with about 5 plates laterally each side of 3rd lobe position, diminishing in size towards prepygidium; pygidial submarginal ducts small, randomly distributed, a total of 9 to 11 ducts present; with 7 to 9 long setae, longest 32–37 μm in length. Perivulvar pores in 5 nearly contiguous groups, with 2 to 3 subsidiary groups on each side of prepygidium segments; total of 93–117 pores in main arch and 1–6 pores in each lateral subsidiary group. Posterior spiracles stout, 32–37 μm long and 15–17 μm wide, with four cells at base, without associated pores or microducts. Anterior spiracles positioned close to mouth parts, about 27 μm long and 5 μm wide, perispiracular pores 5-locular, numbering 10–15 by each spiracle; parastigmatic ducts, similar to microducts with a wide opening surrounded by a wider lightly sclerotised ring, numbering 22–42 in an elongate group each side of mesothorax about equidistant between median and margin. Antenna a sclerotised stub with usually 6 setae comprising 1 pair each of stout, medium, and finer setae.

2nd-instar pupillarium ( Fig. 5 vignette), measurements taken from 12 specimens. Mounted material. Shape elongate. Body length 1.52–2 mm, width 0.58–0.8 mm. Ventral derm membranous. Dorsal derm heavily sclerotised in a dense mosaic pattern of dark textured larger spots separated by tiny clear spots from head to abdomen segment I, this pattern then breaking into transverse bars of diminishing width on each abdominal segment posteriorly and absent on pygidium; division lines on abdominal segments II–V broad and crevice-like. Margins from metathorax to pygidium lined with series of macroducts opening onto the margin, and large columnar duct tubercles present from prepygidium segment III forwards to metathorax and absent on pygidium. Submarginal macroducts present on dorsal prepygidium and pygidium, 1 pair on dorsal submedian. Ventral macroducts on pygidial margin each with a transverse lunate opening, one duct between each lobe. With 3 pairs of slender lobes on pygidium with long ventral scleroses. Fringed plates between lobes more finely fimbriate than plates anterior to 3rd lobes, which are more digitate in appearance. Ventral microducts present on prepygidial abdominal segments. Mouthparts, antennae, spiracles and associated pores and ducts bundled together posteriorwards at ecdysis and usually lost during slide-mounting.

2nd-instar female nymph ( Fig. 6 ), measurements taken from 5 specimens.

Body shape fusiform, becoming wider from mesothorax to posterior abdomen and narrower at head when near 2nd moult (as in Fig. 6 ), pygidium rounded; body length 0.58–1.14 mm, width 0.31–0.48 mm, derm membranous except for sclerotisation patches on pygidium. Pygidium with 3 pairs of slender lobes, basally narrowing to a point, 2nd and 3rd lobes progressively smaller than median lobes. Plates finely fimbriate on pygidium, serrate on prepygidial segments. Dorsal macroducts: 1 pair submarginally on segment VII, positioned close to margin, lateral to median lobes, 2 pairs submarginally on VI–II, becoming smaller as far forward as metathorax; submedially 1 pair on V, then replaced by microducts to segment I. Ventral ducts: (i) macroducts with sclerotised lunate opening on margin and associated with a fringe plate: 1 duct between median lobes, then on each side 1 duct in first space (between median and 2nd lobes), 1 duct in second space (between 2nd and 3rd lobes), and 6 ducts to segment III; (ii) columnar gland tubercles, with fringed opening on margin, in close groups on abdominal III–I and metathorax, becoming ordinary gland tubercles scattered submarginally on meta- and mesothorax; (iii) medium size microducts moderately numerous in groups present submarginally on mesothorax, and submedially on abdomen II–V. Antenna with 4–5 setae. Spiracles each about 22–25 µm long, anterior spiracle with 2 perispiracular pores, posterior spiracle without pores.

2nd-instar male nymph ( Fig. 7), measurements taken from 3 specimens.

Similar to female nymph except: body length 0.68–0.82 mm, width 0.31–0.37 mm.

Pygidium with 3 pairs of lobes. Dorsal macroducts more numerous than on female nymph, submedially all one size, 1 to 3 pairs on VI–I (not replaced by microducts); submarginally similar distribution to female nymph but ducts more numerous, plus about 2 pairs microducts submedially on dorsal head. Ventral ducts: similar to female nymph except columnar gland tubercles rather fimbriate on sides and margins. Antennae with 3–4 setae. With 3 pairs of ventral setae on head submedially in a line between mouthparts and anterior margin, in addition to other head setae.

Comments. The main diagnostic feature is the three pairs of lobes on the 2nd-instar pupillarium and 2ndinstar nymphs, but see under L. albotecta above for discussion comparing other species with 3 pairs of lobes, and see key to separate L. trilobata from L. albotecta .

Material examined: HOLOTYPE: Female and pupillarium, here designated. NEW ZEALAND, DN, Aramoana, 12 Jan 2010, A. Sultan, Korthalsella lindsayi , parasitic on Coprosma areolata , #10-007b [1]: 1 F, 1 fpl. Barcode NZAC 02008364.

Paratypes: as for holotype above: #10-007a, c–f [5]: 7 F, 7 fpl, 3 f2nd (2 mature), 3 m 2nd.

Other material examined. SC, Peel Forest, Te Wanahu Flat, 5 Jan 2010, A. Sultan, Korthalsella lindsayi , parasitic on Lophomyrtus obcordata , #10-009 a–c [3]: 7 F, 7 fpl, 1 f2nd (mature); MK, Motuariki Island in Lake Tekapo, 9 Oct 1973, B.P.J. Molloy, Korthalsella lindsayi and K. clavata parasitic on Muehlenbeckia , from herbarium sheet CHR 286231 #09-346a–c [3]: 6 F, 7 fpl; as previous except small island near Motuariki Island, 9 Jan 2010, A. Sultan, Korthalsella clavata , #10-004a–e [5]: 10 F, 10 fpl; as previous except Korthalsella lindsayi , #10-003 [1]: 2 F, 2 fpl; SL, Winton, 8 Dec 1882, T. Kirk, Korthalsella lindsayi , from herbarium sheet WELT SP 031420, #10-045a–d [4]: 6 F, 6 fpl, 2 f2nd.

Etymology: the species name trilobata refers to the uncommon feature of three pairs of lobes on the 2ndinstar pupillarium and on the 2nd-instar female and male nymphs.

Figures

FIGURE 1. New Zealand Korthalsella species in life. A, young fruiting K. clavata parasitic on Coprosma propinqua; B, flowering K. salicornioides parasitic on Leptospermum scoparium; C. fruiting K. lindsayi parasitic on Melicope simplex; D, Leucaspis trilobata sp. nov. on K. lindsayi.

FIGURE 5. Leucaspis trilobata Henderson sp. nov., adult female. Pupillarium with vignette of dorsal sclerotisation pattern.

FIGURE 6. Leucaspis trilobata Henderson sp. nov., 2 nd-instar female nymph.