OF PSEUDOCOCCIDAE & ERIOCOCCIDAE 19 



groups), and with the anterolateral extensions surrounding the prescutum latero- 

 posteriorly. These lateral extensions are produced into the prealares (pra), from 

 which they are separated by the secondary prealar ridges (prar) ; the latter are 

 anteriorly invaginated into small finger-like apodemes (a), and posteriorly support 

 small anterior notal wing processes (anp). Each prealare is laterally differentiated 

 into a strongly sclerotized triangular plate (tp) which forms the antero-dorsal 

 boundary of the episternum ; this plate was called " prealar wing process " by 

 Ezzat (1956). Behind the anterior notal wing processes, the postero-lateral exten- 

 sions of the scutum are inflected downwards and then upwards to form the posterior 

 notal wing processes (pnp) which are attached to the postalare. 



The scutellum (scl) is pentagonal in dorsal view ; antero-laterally bounded by the 

 scutoscutellar suture (sets), and posteriorly by the inward fold of the posterior margin 

 of the notum (rd) ; the semi-cylindrical structure of the scutellum is due to deep 

 inward inflection of its anterior and posterior margins ; these invaginated margins 

 do not meet internally, thus the scutellar foramen which occurs in other families, 

 e.g. Margarodidae, Diaspididae and Coccidae (Theron, 1958 •; Ghauri, 1962 and 

 Giliomee, 1967) is absent in Pseudococcidae (and Eriococcidae). 



The relative lengths and widths of the various mesonotal structures differ con- 

 siderably within the family and the following ratios were found of taxonomic 

 importance : length to width of prescutum ; length of prescutum to length of 

 scutum ; length to width of scutellum ; length of scutellum to length of scutum. 



The posteriormost part of the mesotergum, the mesopostnotum, is overlapped by 

 the metanotum and thus externally invisible. This invaginated part constitutes 

 the mesopostphragma (phr2) which is slightly larger than the mesoprephragma, 

 and also has a small median notch. Laterally, the postnotum gives rise to a pair 

 of strong finger-like postnotal apophyses (pna) within the mesothoracic cavity. 

 Antero-lateral of the apophysis, the postnotum is produced into a postalare (pa) 

 which reaches the pleural area and articulates with the pleural ridge of the meso- 

 thorax. The postalare is reinforced by the distinctly separated anterior and 

 posterior postalar ridges (apar & ppar) ; dorsally, it bears two small processes 

 associated with the posterior margin of the wing and the posterior marginal fold 

 of the notum, respectively. 



The mesopleuron : The mesopleural ridge (plr2) posteriorly articulates with the 

 base of the coxa, and extends antero-dorsally towards the base of the wing. At 

 about half length, the ridge makes the characteristic sharp double bend and carries 

 at this point the internal mesopleural apophysis (pla2) ; externally, this part of the 

 ridge is overlapped by the postalare. The ridge is interrupted at a short distance 

 above the coxal articulation ; this interruption was overlooked by Theron (1958) 

 on describing P. citri, and according to Ghauri (1962) and Giliomee (1967) does not 

 occur in Diaspididae and many Coccidae. The dorsal part of the (plr2) is relatively 

 strong and terminates in a semi-circular pleural wing process (pwp2) ; the anterior 

 margin of the latter is connected with the episternum by means of a ridge-like 

 basalare (bas). Behind the pleural wing process, there is a small sclerite, the 

 subalare (sa), whose articulation with the alary sclerites is rather obscure. The 



