14 MORPHOLOGY AND TAXONOMY OF ADULT MALES 



The abdomen is parallel-sided, with a slightly tapering posterior end. It consists 

 of 8 pregenital segments and the genital segment ; the latter is narrow, elongated, 

 partly sclerotized, and carries the genital organs. The pregenital segments are 

 usually almost entirely membranous (e.g. P. pomeranicum), but sometimes with a 

 small tergite and sternite on each segment (e.g. E. tiliae). Sometimes (the COCCUS 

 group) segments VII and VIII are each produced laterally into a finger- or lobe-like 

 caudal extension ; posteriorly segment VIII usually carries a subdorsal glandular 

 pouch, from the bottom of which two long setae arise ; they serve as a supporting 

 core for a long wax filament. 



The Head 

 Head Capsule 



Theron (1958) showed that, of the three regions of the generalized homopteran 

 head (Weber, 1928 ; 1935), only one of them, i.e. the epicranium, makes up almost 

 the entire head capsule in the Coccoidea ; of the other two regions the so-called 

 ' Vorderkopf " is reduced to a small area around the non-functional mouth opening, 

 while the third, the labium, is absent altogether. Compared with other families, 

 the head of the Coccidae is peculiar in having the anterodorsal part of the head 

 capsule considerably expanded, with the apex sometimes produced into an antero- 

 dorsal bulge. Apparently the enlarged dorsal part has shifted forwards and the 

 ventral part backwards ; this process of transformation appears to resemble rotation 

 about a point near the lateral ocellus. As a result some structures, which in the 

 other Coccoidea are situated on the dorsal surface of the head, have been trans- 

 located forwards or even to the ventral side. Thus the antennae occupy a ventral 

 position, the median crest extends anteriorly over the apex of the head and termi- 

 nates between the antennae, and the ventral part of the midcranial ridge does not 

 reach the apex of the head. At the same time the dorsal membranous area of the 

 posterior part of the head and neck has become extended. The degree of this 

 deformation of the head varies within the family from a condition that is com- 

 paratively normal and similar to the Pseudococcidae (e.g. E. tiliae, Text-fig. 3) to 

 the extreme as shown by C. hesperidum (Text-fig. 32). 



The dorsomedial part of the epicranium, which corresponds to the median crest 

 (mc) of the Diaspididae (see Theron, 1958 ; Ghauri, 1962), is slightly raised, weakly 

 sclerotized, and usually polygonally reticulated, but in a few cases (F. viburni, 

 Ctenochiton sp. ; Text-figs. 14, 16 ; B) with only weak striations. The posterior 

 margin is usually broadly rounded, but sometimes obtuse (/. theobromae, Text-fig. 

 29, B), and somewhat more heavily sclerotized, although no distinct ridge is present 

 as found by Theron (1958) and Giliomee (1961) in the Pseudococcidae. The heavier 

 sclerotization probably serves to strengthen the epicranium in a region where, 

 according to Theron (1958), the mesothoracic muscles are attached. Borchsenius 

 (1957) referred to the median crest as the " cephalic longitudinal plate ". 



In the anterior part of the median crest there is sometimes a linear vestigial ridge 

 (dmcr) , which corresponds to a similar structure found in Planococcus citri (Theron, 

 1958) and interpreted by Theron as a detached dorsal part of the midcranial ridge. 



