OF PSEUDOCOCCIDAE & ERIOCOCCIDAE 17 



Thorax 



Makel (1942) was the first to give adequate attention to the pleural region of the 

 thorax ; Ezzat (1956) gave more detailed illustrations, but Theron's (1958) 

 identification of the thoracic structures reached an incomparably higher standard. 



Prothorax 



The prothorax is distinctly separated from the head by the constricted neck ; 

 in this respect, Pseudococcidae and Eriococcidae occupy an intermediate position 

 between Diaspididae, where the neck region is not differentiated, and most Coccidae 

 where the neck is very well pronounced. The pronotum is represented by the 

 following structures : (1) the collar-like transverse pronotal ridges (prnr), which are 

 medially interrupted and extend laterally on each side ; (2) two small lateral 

 pronotal sclerites (prn), one on each side, anteriorly bounded by the pronotal ridge ; 

 (3) a postero-dorsal pair of small sclerites, the post-tergites (pt). 



The proepisternum is a distinct, triangular and well sclerotized pleural sclerite, 

 on each side of the prothorax ; anteriorly it fuses with the rudiment of the cervical 

 sclerite at a weak point to form one structure, the proepisternum -\- cervical sclerite 

 (pepcv), which is dorsally approached near its anterior end by the pronotal ridge, 

 and anteriorly articulates with the postocular ridge (see lateral views). Posteriorly, 

 this sclerite (pepcv) is fused with a short pleural ridge (plr^, which carries a small 

 invaginated pleural apophysis (plai) ; the pleural ridge extends downwards and 

 articulates with the basal process of the coxa. The proepimeron, which is usually 

 apparent in certain families (Margarodidae and Diaspididae), is entirely indis- 

 tinguishable in Pseudococcidae (and Eriococcidae). 



The dorsal margin of the proepisternum is always heavily sclerotized and ridge- 

 like ; in Ceroputo group, the ventral margin also is similarly sclerotized. 



The prosternum (stni) is reduced to a small and usually triangular plate ; in some 

 species (N. bifrons) the plate is very short and wide, and in others (T. newsteadi) 

 comparatively long and narrow ; in C. insolitus (Text-fig. 35) it is represented by 

 two small separate plates. Posteriorly, the prosternum is usually bounded by a 

 narrow transverse prosternal ridge (stnlr) , which however is absent in Saccharicoccus 

 group and replaced by heavier sclerotization of the posterior margin (Text-fig. 27) ; 

 the median longitudinal ridge of the prosternum, which occurs in many members of 

 the other families (Margarodidae, Coccidae and Diaspididae), is absent in Pseudo- 

 coccidae (and Eriococcidae). 



Dermal structures of the prothorax. The hair-like setae are always present on the 

 prothorax ; in Pseudococcus group, the fleshy setae also occur. These setae are 

 arranged in the following groups : 



(1) The medial pronotal setae (mpns), which are present on the median and sub- 

 median areas between the pronotal ridge and the post-tergites ; 3 or more of these 

 setae are usually present on each side of the median line (P. citriculus, Text-fig. 23), 

 but in other species they are less than 3 (e.g. P. citri, Text-fig. 4), or absent altogether 

 (Octococcus, Ceroputo and Nairobia groups). 



