32 MORPHOLOGY AND TAXONOMY OF ADULT MALES 



The coxa (ex) is short and broad. Its base is strengthened by a well sclerotized 

 basal ridge which articulates dorsally with the pleural ridge by means of a short 

 basal process. The apical margin is also ridge-like and bears an anterior and a 

 posterior process, which articulate with corresponding processes on the trochanter. 

 The hair-like setae on the coxae vary considerably in length, those near the basal 

 process being very short and those near the apex being longer. The longest seta 

 on the inner terminal part, called the apical seta (ase) may be short, i.e. length about 

 half that of the trochanter (e.g. E. tiliae, F. viburni, Pidvinaria spp. ; Text-figs. 2, 

 14, 35 & 37) or long, i.e. as long as the trochanter (ERIOPELTIS group ; Text-figs. 

 24, 26, 27). Coxal bristles were found in some species of the EULECANIUM 

 group (e.g. E. tiliae, N. abietis ; Text-figs. 2, 3 ; M ; cb) and all the species of the 

 COCCUS group (Text-figs. 31, 33, 35, ^y, 38, 41 ; M ; cb), except C. berliniae. 

 They appear to be capitate in all the species of the COCCUS group except P. 

 pomeranicum and pointed in most species of the EULECANIUM group ; in some 

 specimens of E. tiliae both capitate and pointed bristles may occur. The number 

 of coxal bristles varies from 1-2 (average 1-4) in P. bitubercidatum to 5-8 (average 

 6-2) in E. tiliae. 



The trochanter (tr) is elongate, narrow basally and broad distally. The strong 

 basal ridge bears an anterior and posterior articular process and continues for some 

 distance along the outer margin. The trochanter is separated from the femur by a 

 narrow membrane. A minute hair-like seta occurs both anteriorly and posteriorly 

 in the membrane near the basal ridge and a small rigid seta is always present on the 

 outer margin. These setae appear to be proprioceptors. Ventrally near the apex 

 there is usually one, but in some species (e.g. E. tiliae, P. piceae, R. spiraeae) two 

 long hair-like setae. The longest seta, the apical seta (ase), may be comparatively 

 short, i.e. less than i\ times as long as the width of the trochanter (Genus A, C. 

 hesperidum ; Text-figs. 20, 31) or long, i.e. more than 3 times as long as the width 

 of the trochanter (E. tiliae, N. abietis, Eriopeltis spp., Text-figs. 2, 4, 24 & 26). A 

 ring of oval campaniform sensilla are found in the basal half of the trochanter. 

 They are usually 6 in number, but in E. pela up to 8 may be present. 



The femur (fm) varies in shape from being long and narrow, i.e. 6 times longer 

 than wide (C. hesperidum, Genus B ; Text-figs. 31, 33) to short and broad, i.e. 3I 

 times longer than wide (Genus A, S. pranastri ; Text-figs. 20, 22). The distal ridge 

 is well developed and bears an anterior and posterior process which articulate with 

 corresponding processes on the tibia. All the setae are of the ordinary fleshy and 

 hair-like types. 



The tibia (tib) is long and slender. The width/length ratio varies from about 

 1 : 11 in S. prunastri and L. luzidae (Text-figs. 22, 27) to about 1 : 21 in C. hesperidum 

 (Text-fig. 31). Basally it articulates with the femur by means of two processes and 

 distally it is connected to the tarsus by means of a narrow, articular membrane, with- 

 out a sclerotized joint being formed. The relative numbers of fleshy and hair-like 

 setae vary ; in the COCCUS and INGLISIA groups and some species of the 

 EULECANIUM group the fleshy setae are more numerous and in the ERIOPELTIS 

 group and some species of the EULECANIUM group the hair-like setae are more 



