Waxiella africana (Green)

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 199-203

Waxiella africana (Green)

( Figs 90, 91, 92; Map fig. 105)

Ceroplastes africanus Green, 1899: 188 .

Waxiella africana (Green) ; Ben-Dov, 1986: 166.

Material examined: Lectotype adult ♀: South Africa, Cape Colony ( BMNH): 1/1 (split into dorsum and venter but in fair condition: left hand label: Ceroplastes africanus Green = egbarum Ckll. , right label Ceroplastes africanus (africanus crossed out) Green, 1899, Lectotype, designated by Ben-Dov, 1982). Also: paralectotype: similar data ( BMNH): 1/1 (also split into dorsum and venter, poor; remounted and restained by Ben-Dov, 1981). Also: part of type material, Ceroplastes africanus Green , on Acacia sp. , Cape of Good Hope, ( BMNH): 1/1 (also split into dorsum and venter, poor; mounted from dried material, Ben-Dov, 1981) and ( USNM): 6/6 (remounted and restained by Y. Ben-Dov).

Also: South Africa, Eastern Cape Province, Willowmore, 16.ii.1978, on Acacia karroo, J.J. Cellié ( SANC, 5380): 3/3 (young, good; identified as W. africana ); Western Cape Province, Stellenbosch, 23.ii.1978, Acacia karroo, S. Neser ( SANC, 5410): 1/1 (young, good; identified as W. mimosae ); Western Cape Province, Calitzdorp, 20.i.1972, Acacia sp. , V.B. Whitehead ( SANC, 4488): 2/2 (young, good; unidentified); Eastern Cape Province, Grahamstown, 10.iii.1969, Acacia karroo ( SANC, 3645): 2/2 (young, good; identified as W. mimosae ); Western Cape Province, Grassy Park, Acacia longifolia , 22.iii.1960, Chas Major ( BMNH): 1/1 (good; identified as C. mimosae ); Western Cape Province, Stellenbosch, on Acacia sp. , 8.vi.1954, C.J. Joubert ( BMNH): 3/3 (fair-good, identified as Gascardia sp. ); Gauteng Province [Transvaal], Pienaarspoort, 5.ii.1964, C.J. Cilliers ( SANC, 848): 1/ 1 (young, good; identified as Gascardia mimosae ); Gauteng Province [Transvaal], Pienaarspoort, 20.x.1954, Acacia karroo , E.C.G. Bedford ( BMNH): 1/2 (fair; identified as C. mimosae ). Namibia, Okahandla [Okahandja], no host, F. Gaedes ( BMNH): 1/1 (good, identified as C. mimosae ).

Note. Main description from Lectotype, data from other material in (..) brackets.

Unmounted material. “Insects crowded on the stems of the plant, so much so that the waxy covering of adjacent individuals becomes more or less confluent and the normal form of the test is difficult to determine. The tests appear as rounded masses of cream-coloured wax, each with a more or less nipple-like prominence at the apex bearing a small spot of white substance. The usual opaque white bands from the spiracular regions are present, but very inconspicuous, scarcely extending beyond the margin. In some specimens, a series of impressed arches on the sides of the test marks the position of the marginal plates. The waxy coating being thinner on the impressed parts, the arches appear darker, the colour of the body of the insect showing through the covering matter. An isolated test averages 7.75 mm, 6.50 mm broad, 5.75 mm high.” ( Green, 1899). “Body of fully-grown female convex; dorsal derm sclerotised; with a well-developed cephalic projection extending about 800 µm forward to margin. Anal process short. Young females (slide mounted) 1.6 mm long, 1.2 mm wide. Fully-grown female up to 5.5 mm long, 5.0 mm wide and 4.5 mm high.” ( Ben-Dov, 1986: 166).

Mounted material. Body elongate oval, probably quite convex, with distinct, shallow, stigmatic clefts; dorsum without distinct tubercles. Stigmatic setae of 2 types: ventral sharply-spinose setae amongst spiracular disc-pores and dorsal conical setae in an oval group on dorsum, with cleft surrounded by a wide area of sclerotisation on older specimens. Caudal process short and stout, 2.0 (2.7–3.0) mm long, 2.5 (2.5–2.7) mm wide. Length about 8 mm (young specimens 1.35–1.58) mm, width 6.5 mm (young specimens 0.98–1.23) mm.

Dorsum. Derm membranous, apart from heavily sclerotised caudal process and for a broad area of sclerotisation in all 4 stigmatic areas on old specimens, each nearly twice as broad as group of conical setae; some specimens with light sclerotisation along margins (youngest specimens without sclerotisation on either head or in stigmatic areas). Presence of clear areas unknown (derm with eight clear areas, distributed as usual; dorsomedial clear area rather narrow). Dorsal setae each large and sharply spinose, straight, with more or less parallel sides towards base or slightly constricted; each 11–18 (10–20) µm long; basal socket width 5.0–6.0 (5.5–6.5) µm, each subequal to or wider than loculate microducts; frequent (abundant but absent from all clear areas apart from anterior area which has a few setae). Dorsal pores: (i) loculate microducts of complex type, each with 1–4 small, more or less round, satellite loculi; those with 1 loculus mainly along margins of clear areas and lateral margins; each pore 4–5 µm wide with 2–4 loculi, those with 2 and 3 satellite loculi most abundant; distribution apparently random; abundant throughout apart from clear areas, with no signs of wax-plate lines; and (ii) simple microducts not detected (present in marginal regions of clear areas each with a long inner ductule; not detected elsewhere). Preopercular pores probably present (narrow transverse band of 9–23 pores present). Anal plates each with 3 pairs of dorsal setal sockets, all setae missing (each seta 50–60 µm long), plus a shorter apical seta (33–38 µm long); length of each plate 132 (128–155) µm, width of both plates 150 (140–160) µm. Anal ring setae (each about 155–170 µm long).

Margin. Marginal setae not differentiated from dorsal setae but perhaps a little shorter; frequency unknown due to similarity with dorsal setae; each anal lobe with 1 (1–3) longer seta about 40–46 (28–55) µm long. Stigmatic clefts narrow but distinct, each with 2 types of stigmatic setae: (a) sharply-pointed spinose setae present on ventral surface amongst spiracular disc-pores, each 11–20 (10–23) µm long, with 12–15 (9–23) in each cleft, and (b) roundly conical setae, in a large oval sclerotised area on dorsum on older specimens (sclerotisation absent on young specimens), setae along basal margin larger than most other conical setae, each about 13–15 µm long and 10 µm wide at base; most other setae 8–10 (9–12) µm long and 6–8 (6.5–8.0) µm wide but with a single larger seta about 1/3–1/2 towards centre of each group, each 18–20 (–23) µm long and 10 (–11.5) µm wide; each group with a total of about 85–105 (70–150) conical setae; each group with 3–5 (2–7) conical setae along basal margin, 28–32 (24–36) around dorsal margin and with about 12 (8–17) across widest part; each group almost circular on young specimens but becoming elongate oval on oldest specimens. On older specimens, sclerotisation in each cleft about twice width of stigmatic setal group. Eyespots each perhaps 48 (about 33–35) µm wide.

Venter. Derm entirely membranous but with anterior margin of head heavily sclerotised on old specimens (entirely membranous on young specimens). Pregenital disc-pores abundant around genital opening (segment VII) and across preceding segment ( VI); segment V with a group medially and mediolaterally (10–16 medially + 1–15 mediolaterally); segment IV with 2 medially + 1 mediolaterally (0–7 medially and 0–11 mediolaterally); segments III & more anteriorly with 0 (III 0 or 1 medially and 0–2 mediolaterally; II with 0 or 1 medially; none on thorax). Spiracular disc-pores present in sparse bands (of about 100–120 pores), each band narrow in centre of band, widening considerably near margin, becoming subequal to width of sharply-spinose group of stigmatic setae; none or very few disc-pores extending medially past peritremes. Ventral microducts either very sparse or absent medially on abdominal segments and on meta- and mesothorax. Ventral tubular ducts apparently few in cephalic region on lectotype specimen (but present in a large group of about 30–70 in cephalic area on other material), these extending to area laterad of each scape but with 0 laterally on head, thorax and abdomen (with 0–8 mediolaterally on each side of head anterior to anterior spiracles; rarely with 1–4 ducts mediolaterally on mesothorax and 1 on abdomen); also present medially on abdomen, just anterior to disc-pores: 1 on abdominal segment VII (0 detected), 1 (0–5) on VI, 0 (0–3) on V and 0 (0) on segment IV (i.e., some specimens totally lacking abdominal tubular ducts); some ducts with a long, narrow inner ductule and a small glandular end. Submarginal setae frequent, mostly 16–20 µm long, but some in clefts up to 23 µm (with 7–13 between clefts).

Antennae each with 7, or more usually 8, segments, all segments distinct, total length 370–400 (280–400) µm. Clypeolabral shield missing on all type specimens (about 185–230 µm long). Spiracles: width of peritremes 80–90 (70–95) µm. Legs well developed, each with a well-developed tibiotarsal articulatory sclerosis; claw denticle obscure or absent; claw digitules both very broad and slightly shorter than tarsal digitules; dimensions of metathoracic legs (µm): coxa 173–180 (145–175); trochanter + femur 205–215 (180–227); tibia 145–165 (145–160), and tarsus 80–85 (75–95); claw 30–35 (33–37); setal distribution: coxa 6 (4 or 5); trochanter 1 long seta ventrally plus 2 short setae on dorsal margin; femur 3; tibia 5 (5–7), and tarsus 4 (4 or 5).

Discussion. Ben-Dov (1986) redescribed W. africana based on new material collected from several areas in Cape Province and some of that material was also seen during the above study. Waxiella (Ceroplastes) africana (Green) had been previously synonymised with Waxiella (Ceroplastes) mimosae (Signoret) ( Lindinger, 1912) but, based on the material seen during his study, Ben-Dov (1986) concluded that they were clearly separate species. He considered that they differed particularly in the absence of ventral tubular ducts medially on the abdomen of W. africana , these being present on W. mimosa . In fact, as can be seen from the above description, many specimens of what are here considered to be W. africana (even some listed as having been seen by Ben-Dov, 1986) actually have these ducts—indeed, specimens from the same collection may or may not have them. Good characters for separating these 2 species are: (i) the shape of the group of conical stigmatic setae, narrow with a broad area of sclerotisation on W. africana but almost round with (at most) a narrow area of sclerotisation on W. mimosae ; (ii) the paucity of ventral microducts medially on W. africana , these being much more abundant on W. mimosae , where they are frequent on all abdominal segments; (iii) the absence of multilocular disc-pores laterad to each metacoxa on W. africana , but with (0)–10 pores present on W. mimosae , (iv) the many fewer spiracular disc-pores on W. africana (about 100–120 as compared with 150–250 on C. mimosae ) and (v) the absence of multilocular disc-pores along the anterior border of each band of stigmatic disc-pores and mesad to each spiracle on W. africana (present in both areas on W. mimosae ). In addition, W. africana is here believed to be restricted to southern Africa whereas W. mimosae appears to be restricted to the eastern Sahara area.

Ben-Dov (1986) also commented on the identity of the species studied by Cilliers (1967) (previously identified as W. mimosae ) and suggested that they were probably W. africana . Some specimens collected by Cilliers are amongst the material studied here (see under Material studied above) and this material is clearly W. africana .

Qin and Gullan (1995), on the basis of their morphological cladistic analysis of the wax scales, only found one character separating W. africana , W. mimosae , W. ugandae and W. vuilleti . Here we consider that W. ugandae is a synonym of W. egbarum (see below) but believe that many specimens of these species have been misidentified in the past. Unfortunately, Qin and Gullan (1995) do not list the specimens used in their study and so we cannot check their identity. Here we accept W. africana , W. mimosae and W. vuilleti as good species.

W. africana is very similar to W. senegalensis (raised to specific rank below). Both have the same shaped stigmatic cleft (see Fig. 92) but the group of stigmatic setae on the latter species is somewhat larger and has more conical and sharply-spinose stigmatic setae ( Fig. 92). W. senegalensis appears to be restricted to the northern areas of Africa around the Sahara whereas W. africana is apparently restricted to southern Africa ( South Africa and Namibia) where it has only been collected on Acacia sp. ( A. karroo and A. longifolia ). Because many specimens of Waxiella from countries north of South Africa have been considered to be W. africana in the past, the present list of countries and host plants in ScaleNet ( Ben-Dov et al., 2011) is largely wrong and all records outside South Africa should be treated as misidentifications (see, for instance, material listed below under W. egbara , W. mimosae and W. senegalensis ).