Gigantococcus bicolor (Newstead)

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 : 52-53

Gigantococcus bicolor (Newstead)

Palaeococcus bicolor Newstead, 1917: 5 .

Crypticerya bicolor (Newstead) ; Vayssière (1926: 313).

Gigantococcus bicolor (Newstead) ; Unruh & Gullan (2008: 37) .

Unmounted material. Adult female covered with tufts of white or yellow wax, arranged in seven longitudinal rows, a short median row plus three others on each side, lateral rows continuous and intervening spaces with granular wax. Hair-like setae longest around margins. Ventral abdomen with a thin layer of white wax, not forming an ovisac or marsupium (adapted from Newstead, 1917).

Slide-mounted material. Adult female oval (lectotype 5.4 mm long, 4.8 mm wide). Antennae at least 10 segmented (antennae of lectotype broken). Eyes, mouthparts and legs as for tribe. Thoracic spiracles as for genus; derm at atrial opening with 6–15 simple multilocular pores, each 10–11 µm in diameter, with bilocular or trilocular centre and 6–8 outer loculi. Hair-like setae scattered on derm, longest setae forming dense marginal clusters and with one very long setae on each segment of dorsum in submedial longitudinal rows; long, fine hair-like setae covering ventral surface. Flagellate setae as for genus, densest on ventral head and thorax. Simple multilocular pores, each 10–11 µm in diameter, with bilocular or trilocular centre and 4–6 outer loculi, scattered on ventromedial head and thorax. Simple multilocular pores, each 12–14 µm in diameter, with trilocular (sometimes bilocular or quadrilocular) centre and 6–9 outer loculi, covering dorsal surface and ventral margin. Marsupium present, shaped as for genus, marsupial band made of simple multilocular pores, each 8–10 µm in diameter, with bilocular or trilocular centre and 4–6 outer loculi. Simple multilocular pores, each 10–11 µm in diameter, with trilocular centre and 7–10 outer loculi, surrounding outer edge of marsupial band. Simple multilocular pores, each 10–11 µm in diameter, with bilocular or trilocular centre at 4–8 outer loculi and appearing slightly bluish when stained, scattered on ventromedial abdomen (within marsupial cavity). Multilocular pores, each 8–10 µm in diameter, with quinquelocular or hexalocular centre and 5–8 outer loculi, sparsely scattered across ventral abdomen and around ventral submargin to margin. Compound multilocular pores, each 10–11 µm in diameter, with 8–lobed centre and 6–8 slightly reniform outer loculi, scattered around ventral submargin to margin. Vulvar opening as for genus. Cicatrices hourglass-shaped, numbering 3, subequal in size. Abdominal spiracles as for genus. Anal tube as for genus; anal opening as for genus, surrounded by long, hair-like setae.

First-instar nymph as for genus, except with three pairs of long hair-like setae at abdominal apex, median pair half as long as lateral pairs.

Type data. GHANA [=GOLD COAST]: Aburi, ex Thespesia sp., 1913 (W.H. Patterson) .

Type material. Lectotype here designated: ad ♀, “ W.H. Patterson Aburi. /On Thespesia ./No. 736/Newsteads No. 4/88.”//“Brit. Mus./ Reg. No. 1916.136”//“ Palaeococcus /bicolor, nsp./Newst./Cotype ♀ adult./RN./ Co–type [round sticker]” ( BMNH) . Paralectotypes: pupal ♂, 2 nd -instar nymph, 3 rd -instar nymph (one slide), “ W.H. Patterson Aburi. /On Thespesia ./No. 736./Newsteads No. 4/88/ B.M.N.H. Reg. N.1916.136”//“ Palaeococcus /bicolor, nsp./Newst./Cotype ♀ Juv./B.M.N.H. 1916.136” ( BMNH) ; 2 2 nd -instar nymphs (one slide), “ W.H. Patterson Aburi. /On Thespesia ./No. 736./Newsteads No. 4/88./B.M. 1945, 121”//“Palaeaococcus/ bicolor, nsp./Newst./Co-type/larvae/co-type ♀ Juv./R.N.” ( BMNH) ; ad ♀, 3 3 rd -instar nymphs, ca. 5 2 nd -instar nymphs (dry material), “ Palaeococcus bicolor, Newst (Cotypes) / Aburi / Gold Coast. On Thespesia sp. !1913./ W.H. Patterson (yellow forms)” ( BMNH) .

Taxonomic notes. Refer to the Gi. ewarti group for discussion of similar species.

Newstead (1917: 6) stated that in life this species resembles young adult females of I. seychellarum . He stated also that the wax of the females occurs in one of two colours, yellow and white, and that a single specimen either is entirely white or entirely yellow, with no intermingling of colours. The adult female from the dry material appears to have yellow wax on the dorsal surface and white wax on the ventral surface. Although Newstead believed this species formed neither an ovisac nor marsupium, a careful examination of the lectotype female reveals that it is most likely in a teneral state and had just started to form a marsupial band. The vulva and cicatrices are found towards the middle of the ventral abdomen and in other non-ovisac/marsupium species, those features are found near the posterior end. Also on the ventral abdomen is a transverse row of simple multilocular pores with trilocular centre and 6–8 outer loculi. Posterior to this row are compound pores with an 8–12 lobed centre and 8–10 reniform outer loculi. Anterior to the row of the simple multilocular pores are vulvar pores. Often, species that form neither an ovisac nor a marsupium have a single pore type on the ventromedial abdomen, in addition to the typical vulvar pores.