Gigantococcus bimaculatus (De Lotto)

Unruh, Corinne M. & Gullan, Penny J., 2008, Identification guide to species in the scale insect tribe Iceryini (Coccoidea: Monophlebidae), Zootaxa 1803 (1), pp. 1-106 : 53-54

Gigantococcus bimaculatus (De Lotto)

Icerya bimaculata De Lotto, 1959: 385 .

Gigantococcus bimaculatus (De Lotto) ; Unruh & Gullan (2008: 37) .

Unmounted material. Adult female covered by white cottony wax with two red-orange spots on dorsal surface of thorax, represented by two small areas devoid of any wax covering. Tufts of cottony wax found around margin, tufts shorter and stouter on head and thorax, becoming longer and slender towards posterior end. Ovisac large, rounded, strongly convex, extending beyond posterior wax tassels, which may become broken with age. Total length 10–12 mm (adapted from De Lotto, 1959).

Slide-mounted material. Adult female elongate, 5.9–7.4 mm long, 3.1–4.2 mm wide (paratype 6.8 mm long, 3.9 mm wide) widest across abdomen with a slight constriction just above first abdominal segment. Antennae 11 segmented. Eyes and mouthparts as for tribe. Legs slender, as for tribe. Thoracic spiracles as for genus, derm at atrial opening with 3–5 simple multilocular pores, each with trilocular centre and 6 outer loculi. Hair-like setae as for genus, longest around margins. Flagellate setae as for genus, densest on ventral head and thorax. Compound pores, each 10–15 µm in diameter with trilocular, quadrilocular or quinquelocular centre and 10–14 rectangular outer loculi and appearing slightly bluish when stained, forming dense clusters on ventromedial thorax. Compound multilocular pores, each 18–20 µm in diameter, with quadrilocular, quinquelocular or hexalocular centre and 6–8 semicircular outer loculi, forming segmental clusters on submarginal to marginal venter. Simple multilocular pores, similar to vulvar pores, each pore 10–12 µm in diameter, with trilocular centre and 5–12 outer loculi, scattered on ventromedial head. Compound multilocular pores, each 10–11 µm in diameter, with trilocular centre and 3 elongate rectangular outer loculi, scattered on dorsal medial to submedial head and thorax. Simple multilocular pores, each 9–10 µm in diameter, with trilocular centre and 3–6 outer loculi, scattered across dorsal surface and margin. Ovisac band made of two types of simple multilocular pores: (i) pores forming inner band 3–5 pores wide, each pore 8–10 µm in diameter, with bilocular (rarely trilocular) centre and 10–16 outer loculi, and (ii) pores forming outer band, 1 or 2 pores wide, each pore 8–12 µm in diameter, with trilocular or quadrilocular centre and reniform outer loculi. Simple multilocular pores, similar to vulvar pores, each 10–15 µm in diameter, with bilocular or trilocular centre and 8– 12 elongate outer loculi, scattered on ventromedial abdomen. Vulvar opening as for genus. Cicatrices elongate to reniform, numbering 3. Abdominal spiracles as for genus. Anal tube and anal opening as for genus.

Type data. KENYA: Nairobi , ex underside of leaves of Chaetachmae aristata , 20.viii.1958 and 13.i.1951 (G. De Lotto), Collection Nos. 373 and 2393 .

Type material. Holotype: ad ♀ ( BMNH) (not examined) . Paratypes: ad ♀, “3 Icerya 373/ bimaculata DeLotto /ex Chaetacme [sic] aristata /Nairobi: 13.i.1951 / PARATYPE ” ( USNM); 4 ad ♀♀ ( Kenya Department of Agriculture ) .

Other material examined. KENYA: 3 ad ♀♀, 1 3 rd -instar nymph, Nairobi, ex Schinus sp. , 27.ii.1993 (D. Smith) ( QDPI) .

Taxonomic notes. Gigantococcus bimaculatus looks unlike any other species of iceryine. Several compound multilocular pore types on the derm of this species are not found on any other species.

De Lotto (1959: 385) stated in his description that the holotype was deposited at BMNH, a paratype was deposited at USNM and remaining material was deposited in the collection of the Department of Agriculture, Nairobi, Kenya. His description was based on 6 slide-mounted adult females. We were unable to confirm the presence of slides in the Kenyan depository, but presumably, four of the six females were placed there. DeLotto provided a thorough description and illustration of this species. Based on the structure of the ventral pores, DeLotto believed that it approached Gi. schoutedeni and differed by the number of pores in the ovisac band. Gigantococcus bimaculatus looks unlike any other iceryine species, however, and the pores differ greatly from those of Gi. schoutedeni .