Margarodes Guilding
Creators: name: Watson, Gillian W.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Margarodidae
Margarodes

description: Genus Margarodes Guilding
Margarodes is a genus of 29 species, 14 of which have been recorded from continental Africa. The immature cyst stages (Fig. 6A) feed on roots and are known as “ground pearls”; they have pores in the spiracular atria. Several species are pests in vineyards in southern Africa.
Field key to soil-dwelling cysts of pest Margarodes on grapevines in southern Africa, derived from de Klerk et al. (1982) and de Klerk (2017)}
1(0) Cyst soft and white, no more than 2.5 mm in diameter, subspherical........................................ greeni
- Cyst hard and yellow to bronze, more than 3.5 mm in diameter, ovoid or subspherical.............................. 2
2(1) Cyst wall smooth, yellow to bronze with a metallic lustre, ovoid........................................... trimeni
- Cyst wall textured, dull yellow or brown, subspherical........................................................ 3
3(2) Cyst wall with a bark-like texture, light brown........................................................ capensis
- Cyst wall warty or with a raised reticulated pattern, dull yellow or light to dark brown.............................. 4
4(3) Cyst wall warty, light to dark brown; up to 8.6 mm in diameter...................................... vredendalensis
- Cyst wall with a raised reticulate pattern, dull yellow; up to 6.0 mm in diameter.......................... prieskaensis
Key to slide-mounted cysts of six species of Margarodes in southern Africa, based on de Klerk et al. (1983)
1(0) Abdominal spiracles numbering 6 pairs. Derm around labium without multilocular pores............................ 2
- Abdominal spiracles numbering 7 pairs. Derm around labium with multilocular pores............................... 3
2(1) Cyst with metallic lustre. Maximum body diameter about 6.0 mm......................................... trimeni
- Cyst without metallic lustre. Maximum body diameter about 2.5 mm ....................................... greeni
3(1) Thoracic spiracles associated with multilocular pores on surrounding derm............................. upingtonensis
- Thoracic spiracles not associated with multilocular pores...................................................... 4
4(3) Ventral cicatrices present between abdominal spiracles on segment V and anal opening............. prieskaensis (Fig. 6A)
- Ventral cicatrices absent from area between abdominal spiracles on segment V and anal opening, but present between posteriormost abdominal spiracles and anal opening............................................................... 5
5(1) Cicatrices numbering fewer than 10, present in pairs................................................... capensis
- Cicatrices numbering more than 10, present in pairs and singly...................................... vredendalensis
Key to slide-mounted adult females of ten species of Margarodes in southern Africa, based on de Klerk et al. (1983)
1(0) Abdominal spiracles numbering 8 pairs............................................................... pilosus
- Abdominal spiracles numbering 6 or 7 pairs only............................................................ 2
2(1) Abdominal spiracles numbering 7 pairs.................................................................... 3
- Abdominal spiracles numbering 6 pairs.................................................................... 6
3(2) Posterior end of abdomen with bulbous spines.............................................. prieskaensis (Fig. 6)
- Posterior end of abdomen without bulbous spines............................................................ 4
4 (3) Ventral setae long, each measuring 380‒490 µm.................................................. vredendalensis
- Ventral setae short, each measuring 108‒194 µm............................................................ 5
5(4) Multilocular pores restricted to metathorax and head. Spines present over entire thorax........................ capensis
- Multilocular pores present over entire body. Spines absent from prothorax, present on meso- and metathorax.. upingtonensis
6(2) Abdominal venter with multilocular pores.................................................................. 7
- Abdominal venter without multilocular pores........................................................... ruber
7(6) Multilocular pores present over entire body................................................................. 8
- Multilocular pores absent from both surfaces of head and prothorax, present on other parts of body.................... 9
8(7) With both surfaces of thorax and abdomen densely covered with spines.................................. newsteadi
- Dorsal medial area without spines; marginal and medial areas of ventral metathorax and abdomen with low-density spine covering............................................................................................ greeni
9(7) Mid- and hind-leg claws each long (182‒201 µm), only slightly curved, with inner surface smooth................ trimeni
- Mid- and hind-leg claws each short (71‒100 µm) and strongly curved, with inner surface rough............... peringueyi
description: Published as part of Watson, Gillian W., 2022, Towards identification of the scale insects (Hemiptera: Coccomorpha) of continental Africa: 2. Checklists and keys to six archaeococcoid families, pp. 301-356 in Zootaxa 5105 (3) on pages 308-313, DOI: 10.11646/zootaxa.5105.3.1, http://zenodo.org/record/6332761