Icerya pilosa Green, 1896

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 : 91-93

Icerya pilosa Green

Icerya pilosa Green, 1896: 7 .

Icerya seychellarum nardi Green, 1922: 441 . Synonymy by Rao (1951b: 129).

Icerya nardi Green ; Morrison (1928: 226).

Icerya pilosa nardi Green ; Green (1937: 281).

Unmounted material. Adult female covered by creamy white wax secretion, interspersed with erect tubular filaments. Mature female forming an indistinct ovisac that extends beyond body margin and is covered by long, stout waxy processes produced from ventromarginal area (adapted from Green, 1922).

Slide-mounted material. Adult female oval 2.6–7.5 mm long, 1.7–4.0 mm wide (lectotype of I. pilosa , 3.3 mm long, 1.9 mm wide; lectotype of I. seychellarum nardi 6.0 mm long, 3.6 mm wide). Antennae 8 or 9 segmented; antennal segments appearing more elongate in larger females. Eyes, mouthparts and legs as for tribe. Thoracic spiracles as for genus; derm at atrial opening lined by 5–9 simple multilocular pores with bilocular centre and 6–8 outer loculi. Very straight hair-like setae scattered on derm, longest around margins and at posterior end. Flagellate setae as for genus. Open-centre pores, each 25–30 µm in diameter, 20 µm long, with sclerotized outer rim and 6–8 small, widely spaced outer loculi, forming dense marginal clusters (densest at anterior and posterior margins) and transverse bands across dorsal head and thorax; derm immediately surrounding pore sclerotized. Simple multilocular pores, each 10–12 µm in diameter, with bilocular centre (rarely trilocular) and 6–10 outer loculi, covering dorsal surface and ventral submargin and margin. Ovisac band 2–4 pores wide, made of simple multilocular pores, each 10–12 µm in diameter, with bilocular (rarely trilocular) centre and 6–10 outer loculi. Simple multilocular pores, each 7–8 µm in diameter, with bilocular centre (appearing reniform) and 4 or 5 outer loculi, scattered on ventromedial head and thorax and across ventromedial abdomen. Vulva as for genus. Cicatrix round. Abdominal spiracles in 3 pairs. Anal tube and anal opening as for genus.

Slide-mounted first-instar nymph with very long, straight hair-like setae on dorsal surface. Simple multilocular pores with large bilocular centre (appearing bilobed) and 6–8 outer loculi present around margin and across dorsal head and thorax. Hair-like setae at abdominal apex in 2 pairs.

Type data. Icerya pilosa : SRI LANKA: Chilaw, on a species of wiry grass growing on seashore. Icerya seychellarum nardi : SRI LANKA: Diyatalawa, ex Andropogon nardus .

Type material. Lectotype of I. pilosa here designated: ad ♀, “ Icerya /pilosa/ Green / on Spinifex / Chilaw / Ceylon ” ( BMNH) . Paralectotypes: 2 ad ♀♀, 3 1 st -instar nymphs (same slide as lectotype); 3 ad ♀♀, 3 2 nd - instar nymphs, 1 1 st -instar nymph (all on one slide, same data as lectotype) ( BMNH); dry material ( USNM) . Holotype of I. seychellarum nardi , by monotypy: ad ♀, “ Icerya /pilosa nardi/ Green / on Andropogon /nardus/ iv.1911 / Ceylon. (Diyatalawa)” ( BMNH) .

Other material examined. SRI LANKA: ad ♂, Chilaw , iii.1897 (E.E. Green) ( BMNH) ; INDIA: ad ♀, Andhra Pradesh, University of Hyderabad , ex unidentified grass, 2.xi.2004 (N. B. Hardy) ( BME, CMU157 ) .

Taxonomic notes. Refer to I. pilosa group for a discussion of similar species.

The lectotype female is on the far left of the slide when the original label is held on the left. Green’s (1896: 7) original description of I. pilosa is very brief and the host is "a species of wiry grass growing on seashore”. In a later description, Green (1922: 443) clarified that the host is Spinifex squarrosus , and the type material is labelled accordingly. The adult male is described and illustrated by Green (1922), but according to the information on the slide label, it was collected a year after the type material was described. This slide was incorrectly labelled "type". This species has only been collected on grasses.

The holotype of Icerya seychellarum nardi is much larger than the specimens of I. pilosa (6.0 mm long, 3.6 mm wide and 2.6–3.3 mm long, 1.7–2.1 mm wide, respectively). The difference in size appears to be the only difference between specimens of I. seychellarum nardi and I. pilosa . They share the same pore types and distribution and the size of the open-centre pores found on both species is the same. We examined several specimens of I. purchasi and I. seychellarum in the BME slide collection to investigate the differences in open-centre pore size relative to changes in body size because both species vary greatly in size and have opencentre pores. Within each of these species, we found that a change in body size does not affect the size of the open-centre pores.

Rao (1951b) redescribed this species and, in contrast to Green (1922), did not consider the adult female to produce an ovisac, but rather "a pad of wax secreted by the ovisac band of pores on the ventrum forming a sort of marsupium …"

Green did not formally designate a holotype or type material in his description of I. seychellarum nardi . The present concept, however, is based on a single specimen. Article 72.1.2 of the ICZN states, “If the nominal species group taxon is based on a single specimen, either so stated or implied in the original publication, that specimen is the holotype fixed by monotypy” (ICZN, 1999: 79). Therefore, the single adult female used to describe this species is the holotype by monotypy.