OF THE FAMILY COCCIDAE 35 



plastes spp.) it is weakly sclerotized in the middle. The structure, which can conven- 

 iently be called a cicatrix (c), varies in shape and relative size ; in Ceroplastes spp. it 

 is large, circular and occurs dorsally ; in C. hesperidum and Genus B it is also large 

 but occupies the posterior surface of the lobe and in Parthenolecaniam spp. it is 

 small and occurs apically. The caudal extensions resemble the fleshy tassels of 

 some Monophlebidae (Morrison, 1928), presumably through convergence. Newstead 

 (1916), in describing the male of C. hesperidum, referred to the caudal extensions of 

 the 7th segment as " long slender hairy tubercles " and those of the 8th as " pro- 

 truding gland-like processes ". 



Dermal structures. Both fleshy and hair-like setae are present on the abdomen. 

 They are segmentally arranged and occur in distinct groups on the dorsal, pleural 

 and ventral surfaces and are referred to as abdominal dorsal (ads), abdominal pleural 

 (dps and vps), and abdominal ventral (avs) setae. 



The dorsal setae (ads) normally consist of 2 hair-like setae (one on each side) on 

 all but segments II and III, but in P. bituberculatum and Genus B (Text-figs. 10, 33) 

 they are regularly present on all segments. In addition to these a small but variable 

 number of fleshy dorsal setae occur in the ERIOPELTIS and COCCUS groups 

 (Text-figs. 24-43). 



The pleural setae can be subdivided into a dorsopleural group (dps) and a ventro- 

 pieural group (vps). These two groups are not in line with each other, the former 

 being situated nearer to the posterior margin of the segment. When numerous the 

 two groups coalesce to a certain degree ; on the 7th segment the two groups are not 

 differentiated. The dorsopleural group consists of both fleshy and hair-like setae, 

 occurring in different proportions and numbers in different species. In some 

 species (most of the EULECANIUM group, Text-figs. 2-21) all dorsopleural setae 

 are hair-like ; except for the COCCUS group, there are no fleshy setae on segments 

 I— III, and frequently the anterior segments have no dorsopleural setae at all. The 

 ventropleural setae usually consist of a single hair-like seta and none or but a few 

 fleshy setae ; they are never found on I and rarely on segments II and III. 



The ventral setae are arranged in a median group in the middle of each segment. 

 They often consist of both fleshy and hair-like setae. The hair-like setae are always 

 present, arranged on each side of the body into two longitudinal series, one median 

 and one lateral, each series usually with one seta per segment. Both series are 

 usually present on segments V-VII, but on segments II-IV either median or lateral 

 setae are frequently absent, and on segment II hair-like ventral setae are often 

 absent altogether (e.g. L. htzulae, C. hesperidum, Ceroplastes spp.). In most species 

 (S. prunastri, ERIOPELTIS, INGLISIA and COCCUS groups ; Text-figs. 22-43) 

 fleshy ventral setae are also present. If present, they are usually numerous, except 

 on segment VIII, but a comparatively large number (more than 5) on this segment 

 is characteristic of the INGLISIA group. In S. prunastri fleshy setae occur only 

 on segments II and sometimes III. 



In addition to the above-mentioned setae, a number of setae are present on the 

 posterior margin of segment VIII. Lateral to the glandular pouch this segment 

 always carries 3 hair-like setae ; occasionally a fleshy seta may also be present, 



