Ceroplastes rufus De Lotto

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 96-98

Ceroplastes rufus De Lotto

( Fig. 50; Map fig. 104)

Ceroplastes rufus De Lotto, 1966: 143 .

Cerostegia rufa (De Lotto) ; De Lotto, 1969b: 215.

Material examined: Paratype ♀: South Africa, Western Cape Province, Bitterfontein , on Ruschia (spelt Rhushia) sp., 18.ii.1965, J.H. Giliomee ( BMNH): 2/2 (good but only very young adult females available). Also seen 2 slides with single specimens present in USNM (good) .

Note. Data in brackets from De Lotto, 1966.

Unmounted material. “Test of young adult female rounded, low convex, with dorsal and lateral plates poorly marked; colour reddish brown with a large elongate opaque white boss on the centre of the dorsum; wax very soft.” ( De Lotto, 1966: 143).

Mounted material. Body of young adult females broadly oval with rather marked clefts; without dorsal processes. Caudal process apparently quite large and extending dorso-posteriorly but mainly only lightly sclerotised; process unusual, with anal lobes near apex of caudal process (see figure). Body length 1.5–1.67 (1.4–1.8) mm, width 1.07 mm.

Dorsum. Derm entirely membranous on young individuals, except for a small area of sclerotisation around anal plates. Caudal process also mainly membranous, area of sclerotisation 235–280 µm long, 170–175 µm wide; dorsally, sclerotisation surrounded by a large clear area without dorsal pores or setae. Derm with 6 further clear areas: anterior, medio-dorsal and 1 above each stigmatic cleft; posterior abdominal clear areas apparently absent; each clear area with 1 or 2 dorsal setae. Dorsal setae rather variable in shape, mostly rather pointed but some shorter and more blunter; each about 3–5 µm long, subequal to or slightly longer than width of basal socket (basal socket about 3.5–4.5 µm wide); frequent throughout except scarce in clear areas. Dorsal pores: (i) loculate microducts of complex type, each about 3–5 µm wide, with mainly 1 or 2 small satellite loculi, but pores with 3 loculi quite frequent; frequent throughout but absent from all clear areas; also present on ventral surface of anal process; wax-plate lines not detected; and (ii) simple microducts, rather abundant in all clear areas but not detected elsewhere. Preopercular pores: about 20 pores present in a broad transverse band about 2–3 pores wide, extending along entire anterior margin of anal plates. Anal plates each 153–158 (145–190) µm long, combined width 125 µm; each with 2 or 3 long dorsal setae on posterior quarter of each plate, each 45–80 µm long, plus a shorter setose seta on apex, about 35 µm long. Anal tube short, subequal to length of anal plates or shorter; anal ring setae each about 130–135 µm long.

Margin. Marginal setae intermingled amongst roundly conical stigmatic setae which extend around most of margin; each marginal seta setose, 11–13 µm long; with 6–9 anteriorly between eyespots; 0–2 between eyespots and anterior stigmatic setae, 0 or 1 on each side between stigmatic clefts and about 12–17 on each side of abdomen, mainly along posterior margin where conical stigmatic setae mainly absent; margin also extending from venter along ventral surface of caudal process, each side with 6–11 marginal setae, mostly rather larger than elsewhere, up to 25 µm long; anal lobe setae apparently present on apex of caudal process, each 27–35 µm long. Stigmatic clefts quite deep, each with a group of stigmatic setae about 3–5 setae deep in each cleft but narrowing to 1–2 setae deep along most of rest of margin [ De Lotto, 1966, p. 144 shows the marginal band as being up to perhaps 3 setae wide]; those along margin mainly quite small (about 5–7 µm long, 4–5 µm wide at base) but with a few rather larger setae slightly displaced onto dorsum (each about 9 µm long, 7.5 µm wide at base); each cleft with up to 10 even larger setae; all stigmatic setae either roundly conical or with a slightly flattened apex; frequency impossible to count but with 30–34 small and 2–7 larger setae between eyespots; totals perhaps about 180 per side; stigmatic setae absent from posteriormost part of margin. Eyespots rather small and inconspicuous, each about 17–20 µm wide.

Venter. Derm entirely membranous in young specimens. Pregenital disc-pores present around vulva and across preceding segment, and then with 1–3 medially and 5–13 associated with anogenital fold in segment V plus 1 medially in IV; none on thorax. Spiracular disc-pores in broad bands about as wide as peritreme; with none more medially. Ventral microducts absent medially on abdominal segments V–VII. Ventral tubular ducts, each with a short bulbous inner ductule, present in a sparse group of 10–24 anterior to antennae and in a very sparse submarginal band (1 or 2 laterally on head, 1–8 on thorax and several laterally on abdomen); most abundant posteriorly associated with anogenital fold where frequent (probably at least 10–14 on each side); absent medially. Submarginal setae much more frequent than marginal setae.

Antennae each with 8 (7 or 8) segments but segmentation often obscure; segment III with 2 pseudo-articulations; total length 175–200 (170–190) µm. Clypeolabral shield about 165 µm long. Spiracular peritremes each 58–60 µm wide; muscle plate very short. Legs much reduced but generally with all 5 segments visible although tibia and tarsus often fused; without a tibio-tarsal articulation and sclerosis; total length of metathoracic legs 140–145 µm; tarsal digitules 21–25 µm long, probably not capitate; claw digitules both narrow, with very small capitate apices, each about 17 µm long; claws all very short, without a denticle.

Discussion: C. rufus De Lotto is rather unlike any other Ceroplastes species known from Africa. De Lotto (1966) suggested that this species is close to C. rubens (Maskell) but it is not clear why he thought this. Although the available specimens were very young, they were unique in having the following combination of characters: (i) roundly convex stigmatic setae extending around most of the margin, mainly in a double band, the more dorsal setae largest ( C. singularis Newstead also has stigmatic setae all around margin but they are more sharply pointed and not in this arrangement); (ii) ventral tubular ducts in a sparse submarginal band ( De Lotto (1966) stated that their frequency varied greatly between specimens); submarginal bands of tubular ducts are also found in C. deceptrix , C. madagascariensis , and C. rusticus ; (iii) the shape and structure of the anal process – with a small area of sclerotisation (but which might be much larger in older specimens), and with the body margin extending to the apex of the anal process; (iv) only 6 dorsal clear areas; (v) very reduced legs (also known in C. brevicauda , C. destructor , C. luteolus , C. reunionensis and C. rubens ), (vi) rather pointed dorsal setae, and (vii) 7- or 8-segmented antennae (although some other specimens might not have complete pseudoarticulations and thus appear 6 segmented).

At the present time, C. rufus is only known from Cape Province, South Africa, on Ruschia sp. (Aizoaceae) .