Pulvinaria glacialis, Gertsson & Hodgson

Gertsson, Carl-Axel & Hodgson, Chris, 2005, Four new species of mealybug (Pseudococcidae) and a new species of soft scale (Coccidae: Coccoidea: Hemiptera) from Greenland and redescriptions of a mealybug and a soft scale from Arctic Canada, Zootaxa 897, pp. 1-24 : 14-17

PULVINARIA GLACIALIS Gertsson & Hodgson spec. nov ( Fig. 5 )

(Described from 6 adult females in fair to good condition, 2 split into separate dorsums and venters)

Unmounted material: not seen and no details available.

Mounted material: quite large, 1.8–3.4 mm long and 1.3–3.3 mm wide, more or less oval but slightly more pointed at anterior end; symmetrical and rather flat. Stigmatic clefts absent; anal cleft about 1 / 5 – 1 / 6 th total body length.

Dorsum: derm lightly sclerotised at maturity, with a series of more heavily sclerotised small areas of irregular shape, arranged more or less segmentally, most abundant near margin, becoming less frequent medially. Dorsal setae extremely scarce, possibly even absent on some specimens; when present, rather spinose, very short, only about as long as width of basal socket. Dorsal pores of 3 types: (i) a small microductule with a moderately long inner ductule possibly without a glandular end: throughout, in a small areolation; (ii) a small simple pore, slightly larger than dorsal microductule: possibly present sparsely throughout, and (iii) a small group of preopercular pores anterior to anal plates: each pore closed, roundly oval, probably flat, in a small areolation; few, less than 10. Cribriform plates, dorsal tubercles, and pocket­like tubercles absent. Dorsal tubular ducts small, each with outer ductule about 5–7 µm long, inner ductule 11–13 µm long, with a small glandular end; frequent throughout. Anal plates probably each approximately triangular, 119– 133 µm long and 55–65 µm wide; each with 3 setae, all close to apex and each about 20 µm long, plus a thinner, subapical seta ventrally, perhaps about 12 µm long. Anogenital fold with 2 pairs of setae along anterior margin, each outer seta strong, 50–55 µm long, each inner seta weaker and shorter; lateral margins each with 3 setae; anal ring with six long setae, each about 150–160 µm long. Anal cleft fairly broad, without marginal setae along margins.

Margin: marginal setae stoutly setose, sharply pointed, sometimes slightly to strongly bent towards apex: sparse: with 12–14 between eyespots anteriorly; 6–8 between each eyespot and anterior stigmatic area; 6–8 laterally between stigmatic areas, and 20–24 between posterior stigmatic area and anal cleft; each 16–30 µm long and with a well­developed basal socket. Stigmatic clefts absent; each stigmatic area with 3 stigmatic spines (rarely 2 or 4, and then considered to be deformed); median spine 58–72 µm long, lateral spines 15–22 µm long. Eyespots close to margin on dorsal surface.

Venter: derm membranous. Preanal disc­pores with mainly 10 outer loculi and a large inner loculus: abundant anterior to vulva but becoming much less frequent on anterior abdominal segments as follows: segment VII: about 11 medially + 38–42 on either side of anal cleft; VI: 6–9 between pregenital setae + 14–21 on each side; V: 4–7 between long setae + 3–10 on each side; IV: 7–12 on each side; III: 6 or 7 on each side; II: 4–6 on each side; metathorax: generally 1 between coxae + 1–3 laterad to each coxa; absent elsewhere. Spiracular disc­pores with mostly 5 outer loculi: in moderately broad bands between spiracle and margin, with about 27–31 disc­pores in each anterior band and 33–43 in each posterior band; also with a 0–4 disc­pores mesad to each peritreme; absent elsewhere. Ventral microducts quite large, with a slightly bulbous inner ductule: frequent in a marginal band on head and prothorax; also infrequent to rare medially on head and thorax. Preantennal pores: probably 1 small pore just anterior to each scape. Ventral tubular ducts of 3 main types: (i) with a broad outer ductule, a thin inner ductule and a small glandular end (outer ductule 15 µm, inner ductule 12 µm long): in a broad submarginal band on thorax and abdomen, much less frequent on head and absent anteriorly between antennae; distinctly more common than (ii) a duct with a fairly short outer ductule, a much longer, fairly narrow inner ductule with a large glandular end (outer ductule 10 µm, inner ductule 28 µm): distribution as for type (i) but more frequent submedially and only type present medially on abdomen but inner ductule shorter; and (iii) a duct with a much broader inner ductule and a large glandular end, present medially and submedially on thorax and head, both outer ductule and inner ductule about 16–20 µm long. Ventral setae: small setae infrequent throughout venter; long pregenital setae present on segments VII, VI, & V, length about 90–100 µm; with 3 or 4 pairs of interantennal setae, longest about 65 µm; pro­, meso­ and metacoxae each with 2 or 3 small setae; with 3–5 submarginal setae on each side between lateral stigmatic areas; each 6–13 µm. Antennae 7 segmented, each about 310–320 µm long; setae: scape: 3, pedicel: 1 long and 1 short, segments III 0, IV 4 (1 or 2 long), V 1 fleshy seta (fs), VI 1 fs + 1 hair­like seta (hs), and VII 5 or 6 fs + about 3 other setae; apical seta 40–47 µm long and long setose seta on segment VII 100–115 µm. Mouthparts normally developed; clypeolabral shield about 165–175 µm long; labium with 4 pairs of setae. Spiracles: width of peritremes: anterior 43–50 µm, posterior 55–60 µm. Legs well developed, with a strong tibio­tarsal articulatory sclerosis: measurements (µm) (iii): coxae 125–133; trochanter + femur 160–170; tibia 125–140; tarsus 80, and claw 25– 27; setae: coxa 5 (longest about 42 µm); trochanter 2 (longest 75–80 µm); femur 3; tibia 3 and tarsus 4; tarsal campaniform pore absent; tarsal digitules alike, subequal to length of claw; claw broad; denticle indistinct or absent; claw digitules similar, broad and longer than claw. Vulva opening between segments VII and VIII.

Material studied: HOLOTYPE Ψ: GREENLAND, Søndre Strømfjord, no host, 20.vi. 1952, leg. C. Vibe ( ZMUC): 1 / 2 adΨΨ (holotype clearly marked, other specimen designated paratype).

PARATYPE ΨΨ: as for holotype ( ZMUC, BMNH): 2 / 4 adΨΨ.

Other material: East Greenland, 1892, 1907; Trail #, 12.vi. 1932; Søndre Strømford, 20.vi. 1952; Mestervig, 25.vi. 1953; Charcots Land, 8.viii. 1958. Following all off herbarium specimens of Salix arctica: Lille Snenaes , 26.vi. 1908; Lyells Land (Cape Hedlund), 18.vi. 1932; Nugssuaq, Kutsiaq, 1.viii. 1948; Nugssuaq, Kraulshavn, 23.vii. 1950; Olriks Fjord, 31.vii. 1950; Tugullgssuak, Igdluminerssult, 6–7.viii. 1950; Arfersiorfik, Nunatarujuk, 12.vii. 1987 ( ZMUC).

Comment. P. glacialis is superficially similar to P. ellesmerensis Richards , also collected off Salix arctica , but from Ellesmere Is., arctic Canada, and redescribed below. However, P. glacialis differs from P. ellesmerensis in a number of important features (character­states for P. ellesmerensis in brackets): (i) dorsal setae extremely few, possibly even absent on most specimens (frequent although sparsely distributed); (ii) dorsal setae blunt and extremely short, about as long as width of basal socket (at least 2 x width of basal socket and setose); (iii) antennae 7 segmented (antennae 8 segmented); (iv) marginal setae significantly more abundant than ventral submarginal setae (marginal setae as frequent or less frequent than ventral submarginal setae), and (v) preopercular pores very few, less than 10 (quite abundant, more than 40).

One of us (C­A. G.) searched about 6000 plant specimens for Coccoidea in the Botanical Museum, Copenhagen, belonging to the following genera: Alnus , Betula , Salix , Sorbus , Thymus and Vaccinium ; P. glacialis was found only on Salix arctica .

Figures

FIGURE 5. Adult female of Pulvinaria glacialis Gertsson & Hodgson. Dorsal surface on left and ventral surface on right. Where A = dorsal seta; B = dorsal microductule; C = dorsal tubular duct; D = dorsal simple pore; E = preopercular pore; F = anal plates (dorsal view on left, ventral view on right); G = marginal seta; H = antenna; J = preantennal pore; K 1, K 2 and K 3 = ventral tubular ducts; L = tarsus + claw; M = preanal disc­pore; N = ventral microduct and P = spiracular disc­pore.