OF PSEUDOCOCCIDAE & ERIOCOCCIDAE 21 



of disc pores, namely the mesospiracular disc pores (sp2p) and the median or sub- 

 median postmesostigmatal pores (pmp). 



Metathorax 



The metathorax is largely membranous and the metathoracic sclerites are con- 

 siderably reduced, as a result of the modification of the hind pair of wings into 

 hamulohalterae. The metanotum overlaps the inflected mesopostnotum and is 

 indicated externally by a pair of small lateral suspensorial sclerites (ss), attached 

 to the base of the hamulohalterae by means of a fine sclerotized tendon. The 

 metapostnotum (pn3) is represented at the posterior extremity of the metathorax 

 by small subtriangular sclerites, one on each side of the median line ; these sclerites 

 are usually connected by a distinct transverse metapostnotal ridge (pn3r) (Piano- 

 coccus, Pseudococcus and Saccharicoccus groups) ; this ridge is weakly developed 

 in Octococcus and Ceroputo groups (Text-figs. 31-36), and entirely absent in Nairobia 

 group (Text-fig. 37). The metapostnotal ridge, which is apparently absent in all 

 other studied families, was overlooked by Theron (1958) and illustrated but not 

 discussed by Giliomee (1961). 



The metapleuron : The metapleural ridge (plr3) is well developed and articulates 

 ventrally with the hind coxa ; as the ridge obliquely extends antero-dorsally, it 

 attenuates near the middle where a small metapleural apophysis (pla3) is inwardly 

 invaginated ; at the lower part, the ridge separates two irregular, sclerotized areas, 

 the anterior metepisternutn (eps3), and the posterior metepimeron (epm3) ; dorsally 

 it supports a minute metapleural wing process (pwp3). The precoxal ridge of the 

 metathorax (pcr3) originates below the episternum and extends ventro-medially ; 

 this ridge, while being well developed in Planococcus, Pseudococcus, Saccharicoccus 

 and Octococcus groups, is comparatively weak in Ceroputo and Nairobia groups. 

 The metathoracic spiracle (sp3) is identical with that of the mesothorax, and lies 

 ventro-laterally in the membrane anterior to the metepisternum. 



The metasternum is represented by a pair of small submedian metasternal apophyses 

 (sta) ; according to Ghauri (1962) and Giliomee (1967) these apophyses are absent 

 in Diaspididae and Coccidae. The metasternal plates are absent in Pseudoccidae 

 (and Eriococcidae). 



The dermal structures of the metathorax : Fleshy setae occur in Pseudococcus 

 group only, but the hair-like setae are present in all species. The metathoracic 

 setae include the following groups : The metatergal setae (mts), anterior to the 

 metapostnotal sclerites ; the metapleural setae (mps), just behind the metathoracic 

 spiracles ; the anterior metasternal setae (amss), in the median and the submedian 

 areas on the membrane between the basisternum and the metasternal apophyses ; 

 the postmetastigmatal setae (eps3s), on the metepisternum along its antero- ventral 

 margin, or just below it on the membranous area (this group of setae was found in 

 P. citriculus only) ; and the posterior metasternal setae (pmss), medially on the 

 metasternal membrane behind the metasternal apophyses. 



The following groups of metathoracic derm pores, associated with the corres- 

 ponding groups of setae, are also recognized : The metatergal pores (mtp) ; the 



