34 MORPHOLOGY AND TAXONOMY OF ADULT MALES 



The tergites (at) of segments I— III are situated in the intersegmental or ante- 

 costal region and they usually consist of a small transverse sclerite on each side. 

 Those in front of segment I are enlarged and can perhaps best be regarded as the 

 postnotum of the metathorax ; in the other segments they can be regarded as 

 belonging to the segments posterior to them (similar tergites in Planococcus (Theron, 

 1958) and Pseudococcus (Giliomee, 1961) are probably also intersegmental and do not 

 belong to the preceding segments as has been indicated). In some of the species, 

 e.g. Genus B, Pulvinaria spp. (Text-figs. 33, 35 & 37) the tergites of segments II— III 

 consist of a small sclerite on each side and a separate additional median sclerite, but 

 in Genus A and sometimes in P. myrtilli there is a continuous transverse median 

 sclerite. In segments IV-VIII the tergal plates are large, transverse and situated 

 in the middle of each segment. 



The sternites (as) also consist of large, transverse, segmental plates. In the more 

 anterior and posterior segments they are usually complete, but in the intermediate 

 segments they are either interrupted or completely absent. In some of the inter- 

 mediate segments the membrane near the segmental boundary is bulging and 

 irregularly folded. 



Pleural sclerotization is only found on the caudal extensions of segment VII of 

 the ERIOPELTIS and COCCUS groups (Text-figs. 24-43), on the caudal extensions 

 of VIII in the COCCUS group, and in the pleural region of the INGLISIA group 

 (Text-fig. 30). In /. theobromae a continuous band of sclerotization extends along 

 the pleural region of segments IV-VII, with a small sclerotized area situated some- 

 what more ventrally on each of segments V-VI. This bears some resemblance to 

 the condition in the winged female of Aphis fabae, where the lateral plates occur on 

 abdominal segments II and VI (Weber, 1928) and, according to Weber, are morpho- 

 logically part of the terga. This resemblance is probably merely superficial and 

 devoid of any phylogenetic significance as no lateral sclerotization is present in any 

 of the other Coccoidea studied so far. 



In the COCCUS group, segment VII laterally bears a very prominent, tapering, 

 caudal extension (ce). In the other groups this extension is small and broadly 

 rounded or somewhat pointed. In the COCCUS and ERIOPELTIS groups they 

 are weakly sclerotized lateroventrally. Theron (1958) incorrectly describes them as 

 belonging to abdominal segment VIII and Sulc (1932) correctly illustrates the 

 segmental position in one of his figures (fig. 23), but incorrectly in another (fig. 25). 

 The caudal extension (ce) of segment VIII is also shaped in a variety of ways. It 

 may form a small, simple lobe (the ERIOPELTIS group, the INGLISIA group and 

 most of the EULECANIUM group), a papilla-shaped lobe (Parthenolecanium spp.; 

 Text-figs. 38, 39 ; Q), a large, straight, cylindrical lobe (S. prnnastri, Text-fig. 22 ; 

 C. hesperidum ; Text-fig. 31, Q) or a somewhat geniculate lobe (Genus B ; Text- 

 fig. 33, Q), a mammillate lobe (Pulvinaria spp. ; Text-figs. 35, 37 ; Q) or a prom- 

 inent and semicircular lobe (Ceroplastes spp. ; Text-figs. 41, 43 ; Q). In the 

 COCCUS group the distal part of the lobe is weakly sclerotized and it bears a 

 structure which is usually membranous but weakly reticulated; sometimes (Cero- 



