OF THE FAMILY COCCIDAE 25 



of the postnotum is usually weakly sclerotized and irregular, and may be exposed 

 (e.g. P. myrtilli, Ctenochiton sp., Eriopeltis spp, Ceroplastes spp. ; Text-figs. 12, 16, 

 24 & 26, 41 & 43) or medially overlapped by the metathoracic fold (e.g. E. tiliae, 

 Genus A, I. theobromae ; Text-figs. 2, 20, 29), but this varies somewhat individually. 

 Anterolaterally the postnotum bears a deep finger-like apophysis (pna). Some- 

 times the whole postnotum is polygonally reticulated {Ceroplastes spp.) or reticulation 

 occurs near the anterior margin only (P. corni). At the posterior margin of the post- 

 notum a mesopostphragma is formed which is usually deeply emarginated medially. 

 On each side the postnotum is produced into a strong postulate (pa), which extends 

 anterolaterally to articulate with the mesopleural ridge. The anterior postalar ridge 

 (apar) is well developed, while the posterior postalar ridge (ppar) is weak. The 

 anteroventral part of the postalare is densely reticulated. Dorsally the postalare 

 is produced into two small processes ; the hind margin of the wing is attached 

 to the anterior one, and the posterior marginal fold of the notum to the pos- 

 terior. 



Mesopleuron. A striking feature of the mesopleural region is the strong meso- 

 pleural ridge (plr 2 ). The ridge winds obliquely across the pleuron, with a sharp bend 

 which separates the strongly developed vertical part from the weaker ventral 

 section, the latter extending obliquely towards the coxa. The dorsal part of the 

 ridge gives firm support to the pleural wing process, the ventral extremity articulates 

 with the coxa. The ventral part is partly overlapped by the postalare and at this 

 point a pleural apophysis (pla 2 ) is invaginated. In some species (e.g. F. vibumi, 

 Ctenochiton sp., E. pcla ; Text-rigs. 15, 17, 19) the ridge fades away into the pleural 

 sclerite, as is also the case in the margaroid Steingelia (Theron, 1958) and some 

 Pseudococcidae (Giliomee, 1961). The pleural wing process (pwp 2 ) is a large rounded 

 structure. On its lower anterior margin there is a small tendon-like apodeme (t) 

 from which a muscle extends anterodorsally to the tegula. Posterodorsal to the 

 pleural wing process a small, meniscate subalare (Text-figs. 1, A 1( sa ; 18, N, sa ; 

 18, P) is found. Dorsally it is produced into a finger-like process, which apparently 

 articulates with the second axillary sclerite (Text-fig. 18, N). The basalare (bas) is a 

 narrow but distinct sclerite (in the EULECANIUM, ERIOPELTIS and INGLISIA 

 groups) which connects the anterior margin of the wing process with the episternum, 

 or it is vestigial and incorporated into the pleural wing process (in the COCCUS 

 group). The vertical part of the pleural ridge is separated from the episternum by 

 a strip of membrane which corresponds to the basalar cleft of Matsuda (i960). The 

 episternum (epS2) is large and well sclerotized ; a membranous cleft, extending 

 anteriorly from the region of the pleural apophysis completely divides it into dorsal 

 and ventral parts. The dorsal part is strongly convex and sometimes reticulated 

 (e.g. C . hesperidum, Ceroplastes spp ; Text-figs. 17, 40 & 42) ; the ventral part is a 

 narrow elongated sclerite which joins the lateropleurite anteriorly. The dorsal part is 

 bounded anteriorly by a well developed sitbepisternal ridge (ser). This ridge extends 

 dorsally from the triangular plate of the prealare towards the marginal ridge of the 

 basisternum. Below the membranous cleft, however, it is reduced and only marked 



