Ceroplastes helichrysi Hall

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 44-46

Ceroplastes helichrysi Hall

( Figs 13, 30: Map fig. 103)

Ceroplastes helichrysi Hall, 1931: 295 .

Gascardia helichrysi (Hall) ; De Lotto, 1965: 181.

Material examined: Lectotype ♀ (here designated): Zimbabwe [Southern Rhodesia]: top label: Ceroplastes / helichrysi / Hall / Helychrysum / sp. / Bromley. Bottom label: WJHall 9/3/28 / TYPE / 14.iii.30 WJHall (lectotype top specimen of two).

Paralectotype: other specimen on lectotype slide.

Also: South Africa, Western Cape Province, Grootwinterhoek Mountains, Pampoen Fontein Farm , 700 m, on Cliffortia sp. , 14.ii.2008, P.J. Gullan ( DCBU): 1/3 (fair) .

Note. Description from type series.

Unmounted material. "Test of the adult female convex and pure white. There is a deep submarginal depression giving the marginal area the appearance of being rounded and thickened. The outlines of the plates are indicated by shallow depressions, and each plate carries a rather obscure median circular depression. Centre of the dome with a small elongate raised white boss. There are faint indications of radiating lines and concentric rings on the dome, and a few specimens exhibit a well-marked concentric depression midway between the central boss and the submarginal groove. The wax is firm but not hard. Denuded of its wax, the adult female is highly convex and uniformly rounded, with a faint submarginal depression that is frequently missing in older examples. Cephalic lobes [tubercles] represented, but not at all conspicuous except in the young individuals. Dorsal processes [tubercles] wanting but traces of lateral processes found on a few examples. Caudal process small, triangular, with the apex directed upwards at an angle of 45°. Stigmatic clefts shallow but well marked. Older examples uniformly sclerotised; the dermis is thin and brittle. Length of the test of adult female 5 mm; breadth 3.5 mm." ( Hall, 1931: 295).

Mounted material. Body rather roundly oval and convex, with rather shallow stigmatic clefts; dorsum without lateral tubercles. Caudal process short and cone-shaped, pointing upwards and posteriorly. Length 3.0–4.0 mm, total width on slide 1.9–3.0 mm.

Dorsum. Derm membranous except for a rather narrow band just anterior to anal plates which is distinctly sclerotised; rest of caudal process unsclerotised or only very palely sclerotised, apparently without pores or setae. Derm with 8 clear areas (plus the wide clear area around caudal process); each with very few setae. Dorsal setae all with slightly converging or parallel sides, with a very blunt apex; length 3.0–3.5 µm, slightly shorter than or subequal to width of basal socket, latter 3.5–4.0 µm wide; infrequent throughout but absent from clear areas. Dorsal pores: (i) loculate microducts of intermediate type, each with 2–5 satellite loculi, primary loculus tending to be broader than on most other species; each pore about 3–5 µm widest; those with 3 or 4 satellite loculi generally about equally frequent, those with 5, 2 or 1 much scarcer; microducts sparse throughout but absent from all clear areas; wax-plate lines not detected, and (ii) simple microducts small, occasional in clear areas. Preopercular pores present in a transverse band 2 or 3 pores wide, totalling about 28–32 pores. Anal plates rather elongate; each 115–135 µm long, width of both plates combined 125–130 µm; each with 3 dorsal setae, each perhaps 45–90 µm long, plus a shorter apical seta, 20–25 µm. Anal tube short, about equal to length of anal plates, about 130 µm long; anal ring setae each about 160–180 µm long.

Margin. Marginal setae setose, each 16–23 µm long; rather few, exact numbers uncertain; each anal lobe with perhaps 3 longer setae, longest about 38–45 µm long. Stigmatic clefts each with a group of bluntly conical stigmatic setae extending in a broad group onto dorsum; each group about as long as wide; anterior groups with 30–48 stigmatic setae and posterior groups with 31–52 setae; most setae 7–12 µm wide and 9–11 µm long but each group with 2–5 noticeably larger setae up to about 16–20 µm wide and 30–40 µm long, largest furthest from margin. Eyespots each rather small, about 17–20 µm wide; sometimes not detected.

Venter. Derm entirely membranous. Pregenital disc-pores abundant around genital opening (segment VII) and across preceding segment; present on more anterior segments as follows: medially: segment V several, IV about 3, III about 2, II 0–2, and submedially associated with submedial fold: V several; IV–II 0. Spiracular discpores present in bands of about 100 pores, each band quite narrow near spiracles but broadening near margin; with few, if any, extending medially; those near each cleft more sclerotised and slightly larger. Ventral microducts showing nothing distinctive. Ventral tubular ducts each with a short, narrow inner ductule, sometimes somewhat bulbous at base; abundant anteriorly in a group of at least 30 ducts in cephalic region that spreads laterad to each antenna; also with ducts on abdomen as follows: 1 or 2 medially in abdominal segments III and IV, several medially in V and VI; also present associated with anogenital fold in V and VI, plus a few scattered towards submargin in about segments IV and V. Submarginal setae few and difficult to separate from marginal setae.

Antennae each with 6 (rarely 7) segments, segment III generally with 1 or 2 pseudo-articulations; total length 240–270 µm. Clypeolabral shield about 165–170 µm long. Spiracles: width of peritremes 55–66 µm. Legs well developed, each without a tibio-tarsal articulation; each claw with a small but distinct denticle; claw digitules dissimilar, 1 clearly slightly broader than other but subequal to length of tarsal digitules; dimensions of metathoracic legs (µm): coxa 125–130; trochanter + femur 150–165; tibia 105–115; tarsus 75–80, and claw 25–27.

Discussion. The main characteristics of this species are: (i) the more or less unsclerotised anal process; (ii) presence of several larger spinose setae in each stigmatic group; (iii) rather wide primary loculus in each loculate microduct; (iv) dissimilar claw digitules; (v) small denticle on each claw; (vi) large number of tubular ducts in cephalic region, (vii) absence of tubular ducts laterally on thorax, and (viii) presence of ventral tubular ducts laterally on abdomen. In having a relatively unsclerotised caudal process, C. helichrysi resembles C. brevicauda , but the latter differs in having: (i) reduced antennae and legs; (ii) no ventral tubular ducts anteriorly in the cephalic region, and (iii) loculate microducts of the complex type.

C. helichrysi is currently only known from the original collection in Zimbabwe on Helichrysum sp. (Asteraceae) and from South Africa on Cliffortia sp. (Rosaceae) .