Pulvinaria ellesmerensis, Richards

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 : 20-23

PULVINARIA ELLESMERENSIS Richards ( Fig. 7 )

Pulvinaria ellesmerensis Richards 1964: 1457 ; Ben­Dov, 1993: 257.

Described from 3 adult females in fair to good condition, although unstained.

Unmounted material: not seen and no details available.

Mounted material: quite large, 2.2–2.6 mm long and 1.7–2.2 mm wide, more or less oval but slightly more pointed at anterior end, broadest across anterior abdomen; symmetrical and rather flat. Stigmatic clefts shallow or absent; anal cleft about 1 / 8 – 1 / 9 th total body length.

Dorsum: derm lightly sclerotised at maturity. Dorsal setae finely setose, 5–10 µm long, length at least 2 x width of basal socket: fairly evenly but sparsely distributed over all of dorsum. Dorsal pores of 3 types: (i) a small microductule with a moderately long inner ductule possibly without a glandular end: throughout, each in a small areolation, (ii) a small simple pore: probably present throughout but most obvious near margin, and (iii) small preopercular pores in an elongate group of about 45–60 anterior to anal plates, extending anteriorly about as far a metathorax: each pore closed, roundly oval, probably flat, in a small areolation. Cribriform plates, dorsal tubercles and pocket­like tubercles absent. Dorsal tubular ducts small, each with outer ductule about 6–8 µm long, inner ductule 11–13 µm long, with a very small glandular end; frequent throughout. Anal plates probably each approximately triangular, 160–185 µm long and each plate about 80–85 µm wide; each with 3 setae close to apex, each about 20–33 µm long, plus a thinner subapical seta ventrally, about 14–25 µm long. Anogenital fold with 2 pairs of long setae along anterior margin, each outer seta strong, 60–70 µm long, each inner seta weaker and shorter; lateral margins each with 3 setae; anal ring with 8 long setae, each about 185–190 µm long. Anal cleft fairly broad, without marginal setae along margins.

Margin: marginal setae stoutly setose, sharply pointed, sometimes slightly bent towards apex: sparse: with 5–8 between eyespots anteriorly; 3 or 4 between each eyespot and anterior stigmatic area; 3–6 laterally between stigmatic areas, and 14–19 between posterior stigmatic area and anal cleft; each 7–17 µm long and with a well­developed basal socket. Stigmatic clefts sometimes distinct; each stigmatic area with 3 stigmatic spines; median spine 75–85 µm long, lateral spines 20–30 µm long. Eyespots close to margin on dorsal surface.

Venter: derm membranous. Preanal disc­pores with usually 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 6–8 medially + 28–45 on either side of anal cleft; VI: 6 or 7 between pregenital setae + 20–42 on each side; V: 2 between long setae + 12–17 on each side; IV: 15–18 on each side; III: 11 or 12 on each side; II: 8 or 9 on each side; metathorax: with 4–7 laterad to each coxa; absent elsewhere. Spiracular discpores with usually 5 outer loculi: in broad bands between spiracle and margin, with about 51–56 disc­pores in each anterior band and 53–80 in each posterior band, of which up to 10 disc­pores present mesad to each peritreme; absent elsewhere. Ventral microducts quite large, with a slightly bulbous inner ductule: frequent in a marginal band that broadens on head and prothorax; also infrequent medially on head, thorax and anterior abdominal segments. Preantennal pores: a small pore just anterior to each scape. Ventral tubular ducts of mainly 3 types: (i) a duct with a broad outer ductule, a thin inner ductule and a minute glandular end (outer ductule 8 µm, inner ductule 11–13 µm long): in a broad submarginal band on thorax and abdomen, but 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, narrow inner ductule with a large glandular end (outer ductule 8–12 µm, inner ductule 16–21 µm), inner ductules slightly longer medially on abdomen: distribution as for (i) but more common submedially and only type of duct present medially on abdomen; and (iii) a duct with a much broader inner ductule and a large glandular end (outer ductule 13– 16 µm and inner ductule 16–18 µm long): present medially and submedially on thorax and head. Ventral setae: small setae infrequent throughout venter; long pregenital setae present on segments VII, VI & V, length about 160–178 µm; with 4 or 5 pairs of interantennal setae, longest about 50–62 µm; procoxae with 2 or 3 smallish setae, meso­ and metacoxae each with 4 or 5 small setae; with submarginal setae as follows: 5–9 between eyespots anteriorly; 3–7 between each eyespot and anterior stigmatic area; 6–9 laterally between stigmatic areas, and 17–24 between posterior stigmatic area and anal cleft; each 7–12 µm long. Antennae 8 segmented, each about 355–410 µm long; setae: scape: 3, pedicel: 1 long and 1 shorter, segment III 1, IV 0 or 1, V 2 or 3 (1 or 2 long), VI 1 fleshy seta, VII 1 fleshy setae + 1 hair­like seta, and VIII 4 fleshy setae, 5 stiff setae and 2 hair­like setae; apical seta 50–58 µm long and long setose seta on segment VIII 115 µm. Mouthparts normally developed; clypeolabral shield about 165–180 µm long; labium with 4 or 5 pairs of setae. Spiracles: width of peritremes: anterior 68–80 µm, posterior 80–88 µm. Legs well developed, with a strong tibio­tarsal articulatory sclerosis: measurements (µm) (iii): coxae 165–182; trochanter + femur 205–250; tibia 140–175; tarsus 90–105, and claw 28–30; setae: coxa 5 (longest about 75 µm); trochanter 3 (longest 130–150 µm); femur 3 or 4; tibia 6 or 7 and tarsus 4 or 5; tarsal campaniform pore absent; tarsal digitules alike, longer than length of claw; claw broad, usually with a fairly distinct denticle; claw digitules slightly dissimilar, one marginally narrower with a smaller apex. Vulva opening between segments VII and VIII.

Material studied: PARATYPES Ψ: CANADA: Ellesmere Is, Lake Hazen, 9.viii. 1962, J.A. Downes ( CNC): 3 / 3 adΨΨ.

Comment. The description of the adult female from Ellesmere Island by Richard’s (1964) is rather brief, with few details, and the illustration, whilst essentially accurate, does not give much information. The above description agrees well with that of Richards' (1964) except (Richards details in brackets): (i) pregenital disc­pores with mainly 10 loculi (12, although he illustrates 10); (ii) all the antennae appeared to be 8 segmented (7 segmented); (iii) only 3–6 marginal setae between stigmatic clefts ("up to 15 " ­ but Richards was probably including the submarginal setae), and (iv) anal ring with 8 setae although 2 were much finer than the others (6 setae).

All the material described by Richards (1964) consisted of female stages, and he hypothesized that, because all stages were collected towards the end of the growing season, all stages must overwinter and, as the growing season is short, he suggested that this species might require 5 seasons to complete its life cycle.

Figures

FIGURE 7. Adult female of Pulvinaria ellesmerensis Richards. Labels etc as on Fig. 5, except L = claw.