Ceroplastes luteolus De Lotto, 2012

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 58-59

Ceroplastes luteolus De Lotto stat. rev.

( Fig. 35: Map fig. 103)

Ceroplastes luteolus De Lotto, 1955: 268 .

Ceroplastes luteolus De Lotto ; De Lotto, 1965: 196 (synonymised with C. brevicauda ).

Material examined: Holotype ♀: Kenya, Nairobi , on Coffea arabica , 24.v.1953, G. De Lotto ( BMNH): 1/1 (young, good) . Paratype ♀: Kenya, Nairobi, on Markhamia platycalyx , 17.xii.1953, G. De Lotto ( BMNH): 1/1 (good). Also a single paratype specimen with same data as holotype present in USNM .

Unmounted material. “Test of the adult female more or less hemispherical with a deep depression along the lateral margin, not divided into plates; centre of the dome with a small elongate pad. Colour evenly light yellow with four bands of opaque white wax arising from the stigmatic clefts; wax rather thick and extremely soft. Length 4 to 6 mm; breadth 5–7 mm.” “Denuded of wax, the body of the female is hemispherical, devoid of lateral or cephalic tubercles; caudal process very short, conical and strongly chitinised; dermis at full maturity only moderately chitinised.” ( De Lotto, 1955: 268)

Mounted material. Body roundly oval and convex, with distinct, shallow, stigmatic clefts; dorsum with distinct lateral processes. Caudal process heavily sclerotised, broad and stout. Body length 2.1 mm; greatest width of venter 1.4 mm; greatest width of mounted specimen 1.9 mm.

Dorsum. Derm membranous except for rather evenly and heavily sclerotised caudal process, which has concentric rings rather like a trees’ growth rings. Caudal process about 575–635 µm wide, 540–550 µm long; almost without pores; setae absent. Derm with 8 clear areas, each without simple pores but dorsal setae occasionally present. Dorsal setae each bluntly spinose, subequal to or slightly longer than width of basal socket (length 5.0–6.0 µm; basal socket width 4.5–5 µm); sides parallel or barely converging to a narrow, blunt apex; present rather sparsely throughout. Dorsal pores: (i) loculate microducts of complex type, each with 0–4 satellite loculi, most 6–7 µm wide (larger than basal socket of dorsal setae); pores with 2 or 3 loculi most abundant, those with only 1 occasional, rarely with 0; frequent throughout but absent from all clear areas; wax-plate lines not detected; and (ii) simple microducts apparently restricted to a rather sparse marginal line, each with a sclerotised orifice. Preopercular pores: probably 4–13 present. Anal plates each 133–165 µm long, width of both plates combined 113–145 µm; each plate with 2 larger dorsal setae, each 50–60 µm long, plus 2 smaller setae near apex. Anal tube subequal in length to length of anal plates.

Margin. Marginal setae each strongly setose; most about 15–18 µm long but longer and stouter on either side of stigmatic clefts, where about 25 µm long; separation from submarginal setae difficult but latter thought to be shorter; with about 5–7 anteriorly between eyespots; 2 between eyespots and anterior stigmatic clefts (plus 2 or 3 on anterior margin of cleft); 2–4 between clefts (plus 0–4 on posterior margin of anterior clefts and 2 or 3 on anterior margin of posterior clefts) and about 12 along each abdominal margin (plus 0–2 on each posterior margin of posterior clefts); each anal lobe perhaps with 1 long seta about 45–60 µm long, in normal position. Stigmatic clefts fairly shallow but distinct, each with a roughly triangular group of rather pointed, conical stigmatic setae, each with rather straight sides; length of each group approximately equal to width; each group with 20–39 setae; more dorsal setae in each group larger, and generally with 1 noticeably larger seta towards dorsal apex (latter sometimes bifid); small stigmatic setae each 12 µm long and 8 µm wide, largest setae up to 21–23 µm wide and 16–30 µm long. Eyespots each 35 µm wide.

Venter. Derm entirely membranous. Pregenital disc-pores abundant around genital opening (segment VII) and across preceding segment ( VI); segment V with a group of about 7–21 pores mediolaterally; absent on more anterior segments. Spiracular disc-pores present in broad bands of about 80–90 pores, each band fairly broad near spiracle and then narrowing before broadening near margin, where about as wide as group of stigmatic setae; those nearest margin slightly larger and more sclerotised; sometimes with a few extending medially. Ventral microducts showing nothing distinctive. Ventral tubular ducts absent in cephalic region but frequent mediolaterally associated with anogenital folds in abdominal segments III–VII and medially in V & VI; each with a short, thin, inner ductule. Submarginal setae infrequent and hard to separate from marginal setae, each 10–12 µm long.

Antennae short, each with 6 segments, without pseudo-articulations in segment III; total length 166–180 µm. Clypeolabral shield about 170–186 µm long. Spiracles: width of peritremes 50–60 µm. Legs relatively small, each without a tibio-tarsal articulatory sclerosis; each claw without a denticle; claw digitules of different sizes, 1 much larger than other, and shorter than tarsal digitules; dimensions of metathoracic legs (µm): coxa 62–65; trochanter + femur 78–93; tibia 59–62; tarsus 38–48, and claw 11–15.

Discussion. De Lotto (1965) synonymised C. luteolus with C. brevicauda Hall. It is clear that these 2 species are very similar but the present study suggests that they are possibly distinct. The specimens of C. luteolus seen here appear to be young adults. The caudal process of young adult C. brevicauda is never more than weakly sclerotised – indeed, even on the oldest adult females, the caudal process is never more heavily sclerotised than the rest of the dorsum. The caudal processes of these young C. luteolus , on the other hand, are heavily sclerotised, although admittedly still rather uniform in structure. For further comments, see under G. brevicauda above.

Because the cone that forms the caudal process on C. brevicauda is never heavily sclerotised, the edges of the anal cleft almost always splay widely outwards when pressed down under a cover slip when mounting. This causes the caudal process to take on a rather characteristic shape, much wider than long. On species such as C. luteolus which have a heavily sclerotised caudal process, the caudal process may not split at all, and even when they do, generally they do not splay as widely as on C. brevicauda . One of the consequences of this widely splayed anal cleft is that the anal lobe setae of C. brevicauda appear to lie some way along the margin whereas on C. luteolus they are still clearly in the normal position on the anal lobe.

In addition to the material studied above, some specimens from Democratic Republic of the Congo (Elisabethville [now Lubumbashi], no host, Feb. 1935, per Ch. Scydel (BMNH): 2/5 (mainly good)) were seen. The dorsum of these specimens was very membranous and the caudal process was uniformly but rather heavily sclerotised, suggesting C. luteolus . On the other hand, the caudal process had split and the anal lobe setae appeared to be on the margin, as on C. brevicauda .

C. luteolus is only known from the original collection on Coffea arabica (Rubiaceae) and Markhamia platycalyx (Bignoniaceae) in Kenya. However, De Lotto (1955) wrote “This species … is rather common in the area of Nairobi where it attacks certain cultivated and wild plants.”