OF THE FAMILY COCCIDAE > 3 



laterally to occur anterior to the mesothoracic spiracle. This group therefore 

 corresponds to the prosternal and antespiracular ventral setae of the Pseudococcidae 

 (see Giliomee, 1961). They include both fleshy and hair-like types. The number 

 of these setae varies considerably individually and within the family. The fleshy 

 setae are usually numerous (up to 54) in the COCCUS group and less numerous (up 

 to 25) in the ERIOPELTIS and INGLISIA groups ; they are absent in the 

 EULECANIUM group with the exception of S. prunastri, which has 7-16 setae. 

 The hair-like setae are never more than 4 in number and are often entirely absent. 



In Ctenochiton sp., C. hesperidum and Genus B a number of circular pores, some- 

 what reminiscent of vacant hair sockets, are situated on each side dorsally, posterior 

 to the pronotal ridge. They number 3-7 (average 6-i), 0-1 (average 0-4) and 2-5 

 (average 3-6) respectively. 



Mesothorax 



The mesothorax, as the principal wing-bearing segment, is well developed and 

 sclerite degeneration is much less pronounced than in the other thoracic segments ; 

 in addition, some of the sclerites are bounded by strong ridges. The shape of the 

 sclerotized areas varies comparatively little within the family and consequently 

 provides only a few characters of taxonomic importance. 



Mesotergam. The usual subdivisions of the mesotergum can easily be discerned. 

 Thus the notum (or alinotum) is widely separated from the postnotum, the former 

 being distinctly subdivided into a prescutum, scutum and scutellum ; this was 

 already recognized by Sulc (1932), Pesson (1941) and Jancke (1955). 



The prescutum (prsc) is situated anteromedially and is surrounded laterally and 

 posteriorly by the scutum. It has the shape of a large subrectangular bulge. 

 Anteriorly it curves sharply downwards and forms the mesoprephragma (Text-figs. 

 D) ; the latter has the shape of a simple lamina with the inner margin slightly 

 emarginated in the middle. This emargination varies somewhat individually, but 

 it is inconspicuous or absent in some species (e.g. E. Pfestitcae, Text-fig. 26, D) and 

 pronounced in others (e.g. C. hesperidum and Genus B ; Text-figs. 31, 33 ; D). 

 The phragma was regarded as the prescutum by Ezzat (1956). Laterally the 

 prescutum is separated from the scutum by strong prescutal ridges (pscr), which 

 are fused anteriorly with the mesoprephragma, and extend posteriorly for some 

 distance along the sides of the membranous area of the scutum. The posterior 

 margin is bounded by the prescutal suture (pscs) with its corresponding internal 

 ridge. The median part of the prescutum is often more heavily sclerotized and 

 sometimes a median, ridge-like structure occurs at the posterior (P. bituberadatum, 

 Text-fig. 10) or near the anterior margin (Ceroplastes spp.). In some species the 

 cuticle of the prescutum shows reticulation, which may be regularly polygonal 

 (e.g. P. piceae, L. luzulae, Parthenolecanium spp. ; Text-figs. 6, 27, 38 and 39) or 

 irregular (C. hesperidum, Genus B ; Text-figs. 31, 33). The prescutum has been 

 called the " scutum of the prothorax " (Putnam, 1879), the " proscutum " (Jancke, 

 1955) and the " scutum " (Ezzat, 1956). 



