Waxiella mimosae (Signoret), 1912

Hodgson, Chris J. & Peronti, Ana L. B. G., 2012, 3372, Zootaxa 3372, pp. 1-265 : 215-218

Waxiella mimosae (Signoret)

( Figs 93, 97; Map fig. 105; Table 8)

Ceroplastes mimosae Signoret, 1872: 46 .

Waxiella mimosae (Signoret) ; De Lotto, 1971: 148.

Waxiella tamaricis Ben-Dov, 1986: 171 . Syn. nov.

Type material not seen. Egypt, on Mimosa (Acacia) nilotica (VMNH) ; lectotype ♀ designated by Ben-Dov (1986: 171) .

Material examined. Waxiella mimosae : Egypt, Beni Suef, on “Sunt” ( Acacia nilotica ), 2.x.1922, W.J. Hall ( BMNH): 1/2 (young, good, identified as C. africana ); Luxor, on Acacia sp. , 17.iv.1988, C. Malumphy ( BMNH): 1/1 (fair-good; identified as C. mimosae ); Cairo, no host, 12.vi.1922, W.J. Hall ( BMNH): 1/3 (fair-good; identified as C. africana ); Nag Hamadi, on “Sunt”, 28.iii.1921, W.J. Hall ( BMNH): 1/1 (good; identified as C. africana ).

Waxiella tamaricis : Paratype ♀: Israel, Mivtahim, on Tamarix articulata , 30.xi.1987, Y. Ben-Dov ( BMNH): 1/2 young (good; paratype specimens of W. tamaricis ). Also: as previous ( USNM) 1/2 (good).

Note. The main description is taken from the specimens from Egypt. The data given in (..) brackets are those given by Ben-Dov (1986) for W. mimosae and W. tamaricis combined. See also Table 8.

Unmounted material. “Covered in wax, dirty-white in colour” ( Ben-Dov (1986) after Signoret, 1872). “Young adult female, just after the last moult, is covered with a white wax test; oval in outline, 2.5 mm long, 2.0 mm wide, 0.5 mm high; the test is divided with distinct fissures into 9 plates: median, cephalic, anal and 3 lateral pairs; white mealy secretion (its colour distinctly different from that of the test) extends from the lateral end of each stigmatic furrow towards the dorsal surface of the test; the test at the site of anal opening with a circular area devoid of wax, thus the opening is exposed. In a female of more advanced stage of growth, the test becomes orange-pink; the stigmatic mealy secretions are distinct. In females with a test measuring 4.5 mm long, 4 mm wide, 3 mm high, the anal opening becomes completely covered with the test wax, and remains concealed until the end of oviposition. Fully grown, ovipositing females with a test up to 10 mm long, 8 mm wide and 7 mm high; test colour orange pink, slightly brighter along the margin and on top of the test, stigmatic mealy wax white, distinct, occasionally it is fused with the dorsal test. Body of young adult female 2 mm long, 1.5 mm wide, 1 mm high, without a cephalic projection; body of fully-grown ovipositing female with membranous derm; the cephalic projection well developed, sclerotised; the areas carrying the stigmatic setae sclerotised. Body of fully grown, ovipositing female convex; up to 6 mm long, 5 mm wide, 4 mm high; dorsum sclerotised; with a well-developed cephalic projection.” (Description of W. tamaricis, Ben-Dov (1986: 171)) .

Mounted material. Body elongate oval, probably quite convex, with distinct, shallow, stigmatic clefts; dorsum without distinct tubercles. Stigmatic setae of 2 types, with sharply-spinose setae amongst spiracular discpores and conical setae in a roundly oval group on dorsum. Caudal process short and stout, 0.25–1.12 mm long, 0.25–1.49 mm wide. Body length 2.1–4.5 (2.5–6) mm, width 1.5–3.8 (2–4) mm.

Dorsum. Derm membranous on available specimens except for heavily sclerotised caudal process; older specimens from Nag Hamadi with heavy sclerotisation around anterior margin of head; also each group of stigmatic setae sclerotised but sclerotisation only slightly wider than each group of stigmatic setae; body margins of available specimens not sclerotised. Derm with eight clear areas; mediodorsal clear area rather narrow. Dorsal setae each strongly spinose, straight, with more or less parallel sides or slightly constricted towards base; each 10–19 (15–20) µm long; basal socket width 5–6 µm, subequal to or wider than loculate microducts; abundant but absent from all clear areas apart from an occasional seta in anterior clear area. Dorsal pores perhaps of 1 type only: (i) loculate microducts of complex type, each with 1–5 (2–5) more or less round, satellite loculi; those with 1 satellite loculus rare and mainly along lateral margins; those with 2–5 satellite loculi each about 4–5 µm wide; those with 2–4 satellite loculi most abundant; long, branched inner filament unclear; pores apparently randomly distributed; abundant throughout apart from clear areas; with no signs of wax-plate lines; (ii) simple microducts not detected. Preopercular pores present in a transverse band of 5–16 (10–14), mainly in a single line. Anal plates each with 3 pairs of dorsal setae, each seta 75–85 µm long, plus a shorter apical seta about 50–55 µm long; length of each plate 145–165 (138–170) µm, width of both plates 145–160 (individual plates 62–92) µm. Anal ring setae each about 165–170 µm long.

Margin. Marginal setae similar to dorsal setae but perhaps a little shorter; frequency unknown due to similarity with dorsal setae; each anal lobe with 1 longer seta about 35–50 µm long. Stigmatic clefts fairly shallow, each with 2 types of stigmatic setae: (a) sharply-pointed spinose setae on ventral surface amongst spiracular discpores, each 10–21 µm long, with 17–42 (30–60) in each cleft, and (b) roundly conical setae, in a large sclerotised oval to almost circular area on dorsum; setae along basal margin larger than most other setae and in at least 2 rows; each about 11–13 µm long and 8–12 µm wide at base; most other setae 6–11 µm long and 5–8 µm wide but with a single seta near centre of each group larger, similar to basal conical setae; each group with at least 200 (240–340) conical setae; each group of conical setae with 6–11 setae along basal margin, 40–53 around dorsal margin, and about 21–25 widest part of each group. Eyespots each about 28–33 µm wide.

Venter. Derm entirely membranous on young specimens but anterior area of head becoming heavily sclerotised on old specimens. Pregenital disc-pores abundant around genital opening (segment VII) and across segments VI–IV; segment III with a total about 9–25 medially and mediolaterally; segment II with 4–20 medially and mediolaterally; metathorax with 4–8 medially between coxae; also with 0–10 (0–9) just posterior to each metacoxal articulation [but see discussion below]. Spiracular disc-pores each mainly with 5 loculi but usually with several multilocular disc-pores along anterior border of each disc-pore band; each band with about 150–200 (250) pores, narrow near spiracle but widening considerably near margin, becoming subequal to width of group of sharply-spinose stigmatic setae; with a group of disc-pores also extending medially past peritremes and muscle plates, those furthest from margin becoming multilocular. Ventral microducts very sparse medially and mediolaterally. Ventral tubular ducts present in a large group (50–80) in cephalic area anterior to antennae, these extending to submarginal area laterad of each scape; also with 0–3 laterally on each side of head anterior to anterior spiracles, 0–2 (generally 0) laterally on thorax and rarely 1 laterally on abdomen; also with groups of tubular ducts medially on abdominal segments as follows: 1–12 on VII; 1–10+ on VI; 0–4 on V; 0–3 on III and II; and with a few ducts mediolaterally in segments V & VI but these generally hidden under caudal process; each duct apparently without an inner ductule. Submarginal setae frequent, mostly 14–20 µm long, but some in clefts up to 25 µm.

Antennae each with (6)–8 segments, when less than 8, segmentation sometimes obscure, total length 400–440 (370–456) µm; setal distribution normal. Clypeolabral shield about 205–230 µm long. Spiracles: width of peritremes 80–112 µm. Legs well developed, each with a well-developed tibio-tarsal articulatory sclerosis; each claw rarely with just a hint of a denticle; claw digitules both very broad and slightly shorter than tarsal digitules; dimensions of metathoracic legs (µm): coxa 170–190 (145–210); trochanter + femur 215–260 (205–266); tibia 150–185 (138–190); and tarsus 80–108 (87–110), and claw 33–38.

Discussion. Ben-Dov (1986) considered that W. tamaricis differed from W. mimosae due to the absence of tubular ducts medially on the ventral abdomen. However, the 2 specimens of W. tamaricis seen during this study had 1 and 5 ducts respectively in abdominal segment VI and 1 or 2 ducts in segment VII. As all other characters agree closely with those of W. mimosae , W. tamaricis is here synonymised with W. mimosae . Recently, Ben-Dov and Gurreira (2009) recorded C. mimosae from the Arava Valley in Israel.

The differences between W. mimosae and W. africana (which can also have tubular ducts medially on the ventral abdomen) are discussed under W. africana above. In addition, most of the specimens listed above from Egypt had a few ventral tubular ducts submarginally on the head posterior to each scape or submarginally on the thorax. These have only been noted rarely on W. africana and W. egbarum . Ben-Dov (1986) also suggested that C. mimosae and C. africana differed in: (i) the absence of cruciform pores medially on the abdomen in W. africana (present on W. mimosae ); (ii) slightly longer antennae on W. mimosae than on W. africana , and (iii) the colour of their wax test. It is here considered that these characters are too variable to be reliable. However, W. africana has about half as many conical and sharply-spinose setae in each stigmatic cleft and the shape of each group is quite different (see Table 8 and Fig. 93). For a comparison of W. mimosae with W. egbarum and W. senegalensis , see under those species.

Some of the specimens from Egypt here considered to be W. mimosae had fewer multilocular disc-pores and no multilocular disc-pores just posterior to the metacoxal attachment on one side of the specimen. Some specimens from Mali, Senegal and Saudi Arabia [ Mali, Yelaminé, on Acacia scorpioides , no date, P. Makyrea (MNHN #14780): 1/1 (fair). Senegal, Richard Toll, on Acacia nilotica , 16.viii.1979, B. Sigwalt (MNHN #7862): 1/1 (fair); Matam, on Acacia nilotica , 18.viii.1979, B. Sigwalt (MNHN #7865): 3/3 (fair); Saudi Arabia, South Tihama, on Tamarisk, 21.xii.1975, P.D. Manset (BMNH): 1/2 (fair-poor, identified as W. tamaricis ] lacked loculate pores in this position and also along the anterior margin of the spiracular disc-pore band. In addition, none of these specimens had ventral tubular ducts submarginally in the head and thorax and, whereas all specimens did have spiracular disc-pores extending medially past the peritremes, they were absent elsewhere on the thorax. The identity of this material therefore remains uncertain. It is possible that our diagnosis of W. mimosae should be broadened to include these but they could also be young W. egbara or W. senegalensis .

From our study, it looks likely that all of the records given in Hall (1926) as Ceroplastes africanus refer to W. mimosae . The only other Waxiella sp. accepted in this study as being present in Egypt is W. senegalensis . This latter species is reasonably easily separated from W. mimosae because of the characters given in the key, but particularly by the shape of the stigmatic groups and the distribution of the multilocular disc-pores and ventral tubular ducts on the venter.

As can be seen under material studied for W. africana and W. egbara above, many specimens previously identified as W. mimosae were misidentifications, whereas few of the specimens listed above under W. mimosae had been previously considered to be this species! The only countries for which we have definite records of W. mimosae are Egypt and Israel, and the only hosts are Acacia (Fabaceae) and Tamarix (Tamaricaceae) . All records from elsewhere in Ethiopian Africa should be treated with caution. Thus the record from Mauritania ( Balachowsky & Matile-Ferrero, 1970) is here considered to be more likely to be W. senegalensis .