Pulvinaria tenuivalvata Newstead, 1911

Abdel-Razak, Soad I., Matile-Ferrero, Daniele & Soulier-Perkins, Adeline, 2017, Redescription of the red-striped soft scale, Pulvinariatenuivalvata (Newstead), with a new synonymy (Hemiptera, Coccomorpha, Coccidae), ZooKeys 647, pp. 101-107 : 102-104

Pulvinaria tenuivalvata Newstead, 1911

Lecanium tenuivalvatum Newstead, 1911: 92.

Pulvinaria tenuivalvata (Newstead), De Lotto 1965: 217.

Pulvinaria elongata Newstead; Karam and Abu-Elkhair 1992: 587, misidentification.

Saccharolecanium krugeri (Zehntner); Ali et al. 1997: 149, misidentification.

Pulvinaria saccharia De Lotto, 1964: 863, 2 paratype adult females, South Africa, Natal, Durban, on Saccharum officinarum , J. Munting, 25/03/1964 (BMNH); De Lotto 1966: 468; Hodgson 1968: 207; 1969: 29, 30; Qin and Gullan 1992: 121. syn. n.

Description of the adult female.

Figs 1-6. The adult female of Pulvinaria tenuivalvata is very elongate, convex with the cephalic region flattened. The body colour varies from pale crimson to flesh-coloured with two irregular longitudinal bands of bright crimson on the dorsum. No true ovisac is formed, except under the body where it extends forward to the eyes and may project slightly from beneath the female body.

Body (Fig. 1A): very elongate, oval, narrow at both ends, 3.4-6.5 mm long, 1.5-2.5 mm wide. Derm membranous. Anal cleft rather shallow ranged from 0.70 to 0.74 mm in length. Stigmatic clefts poorly developed.

Margin: marginal setae (Fig. 1B) numerous, slender and pointed, with well-developed basal-sockets, distributed in one row with 12-18 setae on each side between the anterior and posterior stigmatic clefts, mostly about 35-40 µm long, a few only approximately 20 µm long, the longest setae similar in length to the median stigmatic setae (Fig. 2A). Three stigmatic setae present (Fig. 1F) in each stigmatic cleft; these setae short, stout, pointed, the median seta longest (Fig. 2B), straight or more-or-less curved, variable in size and thickness, 25-40 µm long, lateral spiracular setae also variable in size and shape, each 15-20 µm long, pointed (Figs 2B, 5A).

Dorsum: dorsal setae (Fig. 1G) stout, conical, 10-15 µm long, not lanceolate (Fig. 6), scattered all over body surface. Submarginal tubercles absent. Preopercular pores minute (Fig. 1D) about 3 µm in diameter, grouped in small number (6-18) anteriorly to the anal plates. Filamentous pores minute (Fig. 1E), evenly distributed. Anal plates (Fig. 1C1) together quadrate, each plate 125-140 µm long and 70-75 µm wide. Each plate with four short setae; one apical, one subapical, one inner margin seta and one outer margin seta. Ano-genital fold (Fig. 1C2 with two pairs of long anterior marginal setae (a median pair each nearly 45 µm long and a submedian pair each around 65 µm long) and three pairs of long lateral margin setae, 55-65 µm. Anal ring with four pairs of long setae and two rows of pores.

Venter: submarginal setae (Fig. 1J) setose, approx. 7 µm long, placed in a submarginal row. Interantennal setae long, present in three pairs. Prevulvar setae long, one pair on each of the three prevulvar segments. Minute ventral setae evenly distributed. Antennae well developed, eight segmented (Figs 1H, 4), 300-370 µm long, 3rd segment longest. Legs well developed, each with a distinct tibio-tarsal articulatory sclerosis (Fig. 3A), claw without distinct denticle (Fig. 3C). Tarsal digitules, slender, knobbed at apex (Figs 1M, 3B), 45-50 µm long. Hind trochanter + femur 200-260 µm long. Claw digitules unequal, one twice diameter of other, both slender, of the same length, each slightly knobbed at the apex (Figs 1M, 3C), 35-40 µm long. Anterior and posterior spiracles well-developed. Spiracular disc-pores (Fig. 1K) with five loculi, some with four or three loculi, 3-4 µm in diameter, present in a narrow band extending from each spiracle to margin. Multilocular disc-pores (Fig. 1N) with 7-8 loculi, some pores occasionally with fewer loculi, approx. 5 µm in diameter, numerous around vulva, in single rows on all preceding abdominal segments and a few present, submedially, on metathorax and mesothorax. Ventral microducts present, minute (Fig. 1I), sparse. Ventral tubular ducts (Fig. 1L) in a submarginal band, 4 - 6 ducts wide, numerous around entire body, except caudal area and head region where they are sparse. Three types of ventral tubular ducts are present, all of similar diam eter. Type I (Fig. 1L1) long and narrow, numerous, with outer ductule about 20 µm long, approx. 3 µm in diameter, inner ductule approx. 24 µm long, longer and wider than outer ductule and with a large terminal gland. Type II (Fig. 1L2) shorter than type I, less numerous, 10 µm long and 3 µm in diameter, inner ductule 7 µm long, narrower than outer one and with a terminal gland. Type III (Fig. 1L3), the shortest, with outer ductule 5 µm long and inner ductule slender and short, without a terminal gland, very few in number.

Material examined.

Egypt: 100 km south of Cairo, Benisueif, on sugarcane and rarely on maize, M.A. Shalaby,? 1997 (BMNH); upper Egypt, Giza, on sugarcane leaves, 1997 (BMNH); Qena Governorate, Luxor and Qus (700 km south of Cairo), on undersides of sugarcane leaves, S.A. El-Serwy, 01/1999 (BMNH); Giza region, 40-80 km south of Cairo, on Saccharum officinarum (commercial), S.A. El-Serwy, 10/08/1999 (BMNH); upper Egypt, Qena Governorate, on sugarcane leaves, 12/2000 (BMNH); on sugarcane, S. Ramadan, 2011 (MNHN). Uganda: Entebbe, on citronella grass, C.C. Gowdey, 18/02/1910, G. De Lotto, 1960, B.M. 1963-473 (BMNH). South Africa, Natal, Durban, on Saccharum officinarum , J. Munting, 25/03/1964, Pulvinaria saccharia , 2 paratypes, B.M. 1964-662 (BMNH).

Host plants.

The main host plant in Egypt is sugarcane, Saccharum officinarum , but it has also been recorded from several other Poaceae in Egypt: Imperata cylindrica , Sorghum vulgare saccharatum, and Zea mays . The species is known on Cymbopogon citratus (citronella grass) and Pennisetum purpureum in Uganda ( García Morales et al. 2016), and from Zimbabwe and South Africa (Natal), on Saccharum officinarum (as Pulvinaria saccharia ).

Comments.

Two paratypes of Pulvinaria saccharia De Lotto, 1964, have been examined, both adult females. The dorsal setae are short, strong and spiniform, but certainly not lanceolate as stated by the previous authors ( De Lotto 1964; Williams 1982). The claw digitules are unequal, one much thicker than the other one, but of the same length. This character was first observed by De Lotto (1964; 1965) and confirmed by Williams (1982) and Watson and Foldi (2002). These two paratypes show the presence of three types of ventral submarginal tubular ducts, as always. Pulvinaria saccharia has ventral multilocular disc-pores on the metathorax and the mesothorax. The range of setae between the anterior and the posterior spiracles is about 29-31. The combined length of hind trochanter plus femur is about 200-220 µm. On the appearance in life of Pulvinaria saccharia , De Lotto (1964) mentioned that " Pulvinaria saccharia does not form any ovisac but a thin layer of white cottony wax laid beneath the body along the margin". A similar type of ovisac on adult females of Pulvinaria tenuivalvata was observed in Egypt. All these characters fall within the range of the morphological characters of Pulvinaria tenuivalvata , so Pulvinaria saccharia is here treated as a synonym of Pulvinaria tenuivalvata .