Ceroplastes reunionensis Ben-Dov & Matile-Ferrero

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 90-93

Ceroplastes reunionensis Ben-Dov & Matile-Ferrero

( Fig. 48; Map fig. 104)

Ceroplastes reunionensis Ben-Dov & Matile-Ferrero in Ben-Dov et al., 2000: 425.

Material examined: Holotype: Ile de la Réunion, Ravine de Cabris, on Platycerium bifurcatum (Polypodiaceae) , 28.vi.1998, S. Quilici ( MNHN #13805-1): 1/1; also Paratypes: as previous but dated 02.ix.1997, on Lawsonia alba (Lythraceae) ( MNHN #13650-1): 1/1; also as previous but dated 12.ii.1999, on Cycas revoluta (Cycadaceae) ( MNHN #13822-2): 1/3; also as previous but dated 12.ii.1999, on Carissa macrocarpa (Apocynaceae) ( MNHN #13824-4): 1/2; also St. Denis, on C. revoluta , 27.i.1999, J. & Cl. Pierre ( MNHN # 13830): 2/2 (fair-good); also Etang de St. Paul, on Schinus terebinthifolia , 15.iv.2010, Marc Attié ( MNHN #14743): 4/4 (fair-good).

Note. Data from Ben-Dov et al. (2000) in (..) brackets.

Unmounted material. "Wax of young and fully-grown female pure white; wax test observed on 8 host plants in Réunion, being always white; no discernible division into plates. Wax test of young female 2 mm long, 1.5 mm wide, 1 mm high. Wax test of fully-grown female up to 5 mm long, 4 mm wide, 3 mm high. Middle of test with an oval white wax secretion of first instar; submarginal elevation poorly developed. A dry filamentous wax, very conspicuous on background of test, extends from each mesothoracic and metathoracic spiracle to submargin of test. Anal plates exposed. Body of alcohol preserved specimens light yellow brown.” ( Ben-Dov et al., 2000: 425).

Mounted material. Body broadly oval and convex, with distinct, quite deep, stigmatic clefts; lateral and dorsal clear areas distinct. Caudal process short and stout, probably directed upwards. Length 1.6–2.7 mm, width 1.3–2.3 mm; width across venter about 1.2–2.1 mm.

Dorsum. Derm membranous apart from heavily-sclerotised caudal process. Caudal process clearly wider than long on most specimens; length about 160–635 µm; width 180–1080 µm; 1 specimen on Carissa with an elongate process, 635 µm long and about 750 µm wide at base. With 8 clear areas as normal; anterior and dorsal areas with dorsal setae. Dorsal setae each very short and parallel sided, with a truncate apex, subequal to or shorter than width of basal socket, length 3–5 µm; basal socket width 4–5 µm; abundance rather variable, generally present sparsely throughout but possibly most abundant near margins but more abundant on some specimens, when can appear to be most frequent in wax-plate lines; present marginally in most clear areas. Dorsal pores: (i) loculate microducts of type somewhere between rusci-type and intermediate type, abundant, each about 5–6 µm widest, with 1 or 2 (rarely 3) satellite loculi, those with 1 satellite loculus very much more abundant than those with 2 satellite loculi on some specimens (e.g. on Schinus sp. ) but frequency reversed on others (e.g. on Cycas sp. ), when those with 2 satellite loculi appear to be mainly in wax-plate lines; those with 2 satellite loculi of characteristic shape; wax-plate lines indistinct; (ii) simple microducts of perhaps 2 types: (a) a larger microduct with an oval orifice only slightly smaller than smallest loculate microduct; very sparse; and (b) a much smaller microduct, perhaps 1 µm wide, restricted to clear areas. Preopercular pores present in a group of about 10–26 (generally 16–18) pores. Anal plates each 140–160 µm long, width of both plates combined 128–175 µm, each with 3 long flagellate dorsal setae, inner anterior seta 20–35 µm, outer anterior seta 38–40 and that nearest apex about 50 µm long; shorter apical seta not detected. Anogenital fold with 3 pairs of setae on anterior margin, plus 1 or 2 pairs of shorter hypopygial setae. Anal tube fairly short; anal ring setae each about 175–190 µm long.

Margin. Marginal setae similar to dorsal setae but perhaps slightly longer, up to 5 µm long; frequency uncertain due to similarity with dorsal setae; each anal lobe with 3–5 longer setae, longest about 45–50 µm long. Stigmatic clefts quite deep, each with 5 rows of stigmatic setae totalling about 20–30, as follows: with a marginal line of 14–18 (13 or 14) very round, bollard-like setae, each mainly 8–13 (10–17) µm wide; plus a more dorsal, roughly triangular, group of 5–13 setae, similar to or slightly larger than those along margin, each 7–17 µm wide, + 2 significantly larger rounded setae, each 20–25 µm wide, plus, at apex of each group, a much larger, bluntly pointed, spinose seta 45–50 µm long and 25 µm wide at base, occasionally with a slightly bifid apex; basal socket of largest setae 30–33 µm wide. Eyespots oval, not easy to see, rather displaced onto dorsum, each lying radially, each about 16x25 µm wide.

Venter. Derm entirely membranous apart from a small sclerotised area within each stigmatic groove close to margin; also with edges of stigmatic groove near margin more heavily sclerotised. Pregenital disc-pores abundant around genital opening (segment VII) and across preceding segment ( VI) on some specimens; disc-pores noted in segments II, III, and IV but occasionally absent from anterior abdominal segments; generally with a small group of 0–5 disc-pores mesad to each pro- and mesocoxa and occasionally with a single disc-pore laterad to each metacoxa; more anterior disc-pores often with fewer loculi. Spiracular disc-pores present in broad bands of about 100 pores, plus 0–7 extending medially past end of spiracular apodeme to near each pro- and mesothoracic coxa, each often with 7 or 8 (5) loculi; laterally, each disc-pore band about as wide as area of sclerotisation. Ventral microducts showing nothing distinctive. Ventral tubular ducts not detected either anteriorly on head or associated with anogenital fold. Submarginal setae sparse, each about 4–5 µm long.

Antennae quite short, each with 6 segments, segment III with at least 1 pseudo-articulation; total length 140–190 µm; setal distribution normal except only 2 (rather than 3) setae on segment III, and segment V without a hair-like seta. Clypeolabral shield about 150–165 µm long. Spiracles: width of peritremes 55–105 µm. Legs much reduced in size, with trochanter and femur occasionally fused; tibia and tarsus fused; tarsal digitules both capitate but dissimilar, 1 slightly thicker and longer than other; each claw small, claw denticle obscure or absent; claw digitules dissimilar, 1 much broader than other and subequal in length to tarsal digitules; dimensions of metathoracic legs (µm): coxa 50–60; trochanter + femur 37–50, tibia + tarsus 35–50, and claw 8–10.

Discussion. As pointed out by Ben-Dov et al. (2000), the adult females of C. reunionensis are extremely similar to those of C. rubens . Ben-Dov et al. (2000) did a random amplified polymorphic DNA (RAPD) analysis to compare these 2 species and concluded that they were different genetically but almost indistinguishable morphologically. Ben-Dov et al. (2000) suggested that perhaps the best character for separating these 2 species was the number of spiracular disc-pores in the group mesad to each spiracular muscle plate, which tended to be more frequent in C. reunionensis . Although we did not see as many specimens as they did, our data suggest fewer such pores in C. reunionensis than found by Ben-Dov et al. (2000) and so we consider that this character may be less useful. However, one possible character that might be useful is the distribution and frequency of the stigmatic setae. Both species have a short line of 4–7 bollard-like setae along the margin of each cleft. However, on almost all C. rubens seen in this study, there are only 2 further rows of bollard-like setae between the marginal row and the large conical spinose seta: that nearest the margin is composed (usually) of 2 moderate-sized setae and that nearest the conical set has a smallish central seta plus a very large seta on each side. Thus, on C. rubens , there is a marginal row of bollard-like setae, a second row of 2 moderate-size setae, followed by a row of 2 large and 1 small bollard-like setae plus a large conical seta (thus the stigmatic setae might be described as being in 4 rows ( Fig. 49)); the total number of non-marginal bollard-like setae on C. rubens is almost invariably 5–7. The arrangement on C. reunionensis is somewhat similar but there is an extra row of bollard-like setae, so that there are now 5 rows: a marginal row as before, a (new) row of 4+ setae next to the marginal row, then a short row of generally 2–4 bollardlike setae of various sizes, followed by the row with 2 very large bollard-like setae (as on C. rubens ) but sometimes with more than 1 smaller seta, and finally the large cone-shaped seta ( Fig. 48). The differences between these arrangements are also shown in Ben-Dov et al. (2000). Whether these differences would hold for a longer series of specimens is not known.

Another important difference, as also pointed out by Ben-Dov et al. (2000), is in the colour of the test, which is white on C. reunionensis and pinkish on C. rubens . However, it should be noted that the reddish tinge to the wax test of C. rubens fades quite quickly in specimens kept in alcohol.

The above description agrees reasonably closely with that of Ben-Dov et al. (2000) apart from the size of the dorsal setae. The dorsal setae were all extremely short on all specimens of C. reunionensis seen in this study, never longer than the width of the basal socket (about 5 µm at most), whereas Ben-Dov et al. (2000) describe them as “10 µm long, 2–4 times as long as width of setal base”. In addition, the original type material was collected on 4 different host plants belonging to 4 different plant families. In the present study, it was noted that the specimens on Carissa tended to be noticeably smaller than those on the other hosts, with smaller spiracles and tibia + tarsus, and with fewest stigmatic setae. Nonetheless, the difference in the stigmatic setal arrangement outlined above still held.

C. reunionensis is currently only known from the island of Réunion ( Mauritius) from seven plant families: Carissa macrocarpa (Apocynaceae) , Cycas revoluta (Cycadaceae) , Lawsonia alba (Lythraceae) , Mangifera indica (Anacardiaceae) , Persea americana (Lauraceae) , Platycerium bifurcatum (Polypodiaceae) , Syzygium malaccense and S. samarangense (Myrtaceae) .