Leucaspis albotecta 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 : 5-10

Leucaspis albotecta Henderson sp. nov.

Figs 2–4

Unmounted material. Pupillarial; exuviae terminal, pupillarium light brown with a white waxy coating; adult females membranous; male covers bright white and relatively thick, with dark terminal exuviae.

Adult female ( Fig. 2 ), measurements taken from 14 specimens.

Mounted material. Body length 1.62–2.3 mm, width 0.56–0.92 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 slightly rounded distally, about 12 μm long and 6 μm wide including basal sclerotisation; plates extending well beyond lobes, tapering to a point, lightly fringed on each side, with 2 to 3 plates in each space between lobes, this variable with varying lobe positions, and with about 5 plates laterally each side of 3rd lobe position, diminishing in size towards prepygidium; pygidium submarginal ducts small, randomly distributed, a total of 9 to 15 ducts present; longest setae 12–32 μm in length. Perivulvar pores in 5 nearly contiguous groups, with 2 to 3 additional subsidiary groups on each side of prepygidium segments, having a total of 108–132 pores in main arch and 5–16 pores in each lateral subsidiary group. Posterior spiracles stout, 27–37 μm long and 15–17 μm wide, with four cells at base, without associated pores or microducts. Anterior spiracles 25–30 μm long and positioned close to mouth parts, perispiracular pores 5-locular, numbering 16–31 by each spiracle; parastigmatic ducts similar to small gland tubercles, numbering 22–40 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. 2 vignette), measurements taken from 15 specimens.

Mounted material. Shape elongate. Body length and width as above. Ventral derm membranous. Dorsal derm heavily sclerotised in a dense mosaic pattern of dark and 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 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 and submedian macroducts present on dorsal prepygidium and pygidium. Ventral macroducts on pygidial margin each with a transverse lunate opening, one duct between each lobe. With 3 pairs of club-shaped 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. 3 ), measurements taken from 1 specimen.

Body shape fusiform, narrower at head, pygidium rounded, length 0.67 mm, width 0.29 mm, derm membranous except for sclerotisation patches on pygidium. Pygidium with 3 pairs of lobes, club-shaped, broader at body margin and basally narrowing to a point, apex square, 2nd and 3rd lobes progressively smaller than median lobes. Fringed plates either side of median lobes appearing digitate (but only 1 specimen seen here so fineness of fringing may vary), finely fimbriate lateral to 2nd and 3rd lobes, becoming finely serrate on prepygidial segments. Dorsal macroducts: 1 pair submarginally on segment VII, positioned lateral to anterior end of median lobes, 2 pairs submarginally on VI–III, becoming smaller as far forward as metathorax; submedially 1 pair on VI, 2 pairs on V and IV, then a few microducts on III. Ventral ducts: (i) macroducts with sclerotised lunate opening on margin, each 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 7 ducts to segment III; (ii) columnar gland tubercles, smooth-sided and lacking fringed opening on margin, in close groups on abdominal II–I and metathorax, becoming normal gland tubercles scattered submarginally on mesothorax; (iii) medium size microducts moderately numerous in groups present submarginally on mesothorax, and submedially on abdomen II–V. Antenna with 4–6 setae. Spiracles each about 22–25 µm long, anterior spiracle with 4 perispiracular pores, posterior spiracle without pores.

2nd-instar male nymph ( Fig. 4 ), measurements taken from 6 specimens.

Similar to female nymph except: body length 0.64–1.2 mm, width 0.28–0.44 mm.

Pygidium with 2 or 3 pairs of lobes, 3rd lobes sometimes more plate-like than lobular. Fringed plates generally finely fimbriate on pygidium. Dorsal macroducts more numerous than on female nymph, submedially 1 to 4 pairs on each of segments VI–II then becoming short, wide microducts in rows on II–I and mesothorax, with about 2 pairs submedially on dorsal head; submarginally similar distribution to female nymph but ducts more numerous. Ventral ducts: (i) macroducts with sclerotised lunate opening (similar to female nymph); (ii) columnar gland tubercles (less numerous); (iii) microducts few submedially on abdomen I–V. 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 female nymph, (this feature shared with the second new species L. trilobata described below but see the key for distinctions) which previously was known only from two other species. The first of those other species is Leucaspis senilobata Green on which the 3rd pair of lobes is inconsistently present; also, L. senilobata usually has a 5-locular pore on the ventral pygidium just anterior to each 3rd lobe (or its position), and always has 2 pairs of lunate marginal macroducts between the 2nd and 3rd lobes (always a single lunate duct there on L. albotecta ); lastly, host plant preferences for L. senilobata are Griselinia and Hebe . The second species with three pairs of lobes is an undescribed species outside the scope of this paper, which cannot be confused because it is about half the size of L. albotecta , and because its host plant preferences are Halocarpus biformis , H. bidwillii , Manoao colensoi (Podocarpaceae) and Libocedrus plumosa (Cupressaceae) . With regard to the adult female L. albotecta , the presence of subsidiary abdominal pore groups places it outside the group of species discussed by de Boer and Valentine (1977). However, many more species are known that do have subsidiary pore groups. The remaining described Leucaspis species unfortunately lack sufficiently good descriptions for useful comparison.

Material examined: HOLOTYPE: Female and pupillarium, here designated. NEW ZEALAND, CO, Lake Roxburgh, 11 Jan 2010, A. Sultan, Korthalsella salicornioides parasitic on Kunzea ericoides , #10-008a [1]: 1 F, 1 fpl. Barcode NZAC 02008535.

Paratypes: as for holotype: #10-008b-d [3]: 6 F, 6 fpl, 1 f2nd, 1 m 2nd, 1 exuv1.

Other material examined. NEW ZEALAND, MB, Wairau Valley, Branch River, Feb 2010, A.W. Robertson, Korthalsella salicornioides , #10-068 [1]: 1 F (parasitised), 2 fpl, 1 m 2nd, 1 1st; WA, Lake Wairarapa, Western Lake Road, Lake Shore Scenic Reserve, March 2010, A. Sultan, #10-094a–b [2]: 2 F, 3 fpl, 1 exuv1; BP, Rotorua Whakarewarewa Geothermal Reserve, 10 Apr 2010, A. Sultan, Korthalsella salicornioides , #10-063a–d [4]: 2 F, 2 fpl, 5 m 2nd, 1 1st, 2 exuv1; as previous except Jan 1920, D. Petrie, from herbarium sheet WELT SP 031442, #10-046 [1]: 2 F, 2fpl; [no collection data] Korthalsella salicornioides , from herbarium sheet MPN 31332, #10-097a–b [2]: 2 F, 3 fpl, 1 exuv1.

Syntype material of Leucaspis senilobata was examined when previously on loan to RCH from the Natural History Museum, London.

Etymology: ‘albo’—white, combined with ‘tecta’—covering, for the abundant white male scale covers noted in the type series collection.

Figures

FIGURE 2. Leucaspis albotecta Henderson sp. nov., adult female. Pupillarium with vignette of dorsal sclerotisation pattern.

FIGURE 3. Leucaspis albotecta Henderson sp. nov., 2 nd-instar female nymph.

FIGURE 4. Leucaspis albotecta Henderson sp. nov., 2 nd-instar male nymph.