OF THE FAMILY COCCIDAE 129 



berliniae). (iii) the total number of setae on the fore tibia and the preponderance 

 of fleshy setae on the hind tibia separate the COCCUS and INGLISIA groups from 

 the ERIOPELTIS group, but only distinguish genera within the EULECANIUM 

 group. Other characters are mainly significant at the generic and specific levels, 

 e.g. (i) the relative lengths of the apical setae on the coxa and trochanter, (ii) the 

 shape of the femur, (iii) the size of the apical spur of the fore tibia in relation to 

 those on the other tibiae, (iv) the length of the fleshy setae in relation to the width 

 of the tibia, (v) the number of fleshy setae relative to the number of hair-like setae 

 on the hind tarsus, (vi) the length of the hind tarsus in relation to its width and 

 (vii) the relative length of the hind claw. 



The Abdomen. 



The abdomen and genitalia also provide a series of important characters. The 

 number of tergites and sternites usually vary within the group. The absence or 

 degree of development of the pleural sclerotization, however, remains constant 

 within the groups. A prominent, tapering caudal extension on segment VII is char- 

 acteristic of the COCCUS group. The shape of the caudal extension of segment 

 VIII and the position and size of the cicatrix differentiate the genera of the COCCUS 

 group. The number of dorsal abdominal setae on certain segments varies somewhat 

 individually, but can be used as a supplementary character to separate genera and 

 species. The length of the setae of the glandular pouch shows considerable differ- 

 ences between species and genera ; in Luzulaspis lu:ulae the pouch itself is absent. 

 The presence of fleshy setae lateral to the glandular pouch is characteristic of the 

 genus Ceroplastes. Fleshy pleural setae occur in the ERIOPELTIS, INGLISIA 

 and COCCUS groups and the genus Sphaerolecanium, but only in the COCCUS 

 group are they present on segments I— III. Fleshy ventral setae are characteristic 

 of the same genera as the pleural setae, but Sphaerolecanium differs from the others 

 in that the fleshy setae only occur on segments II and sometimes III ; a large 

 number of fleshy setae on segment VIII is typical of the INGLISIA group. The 

 number and arrangement of the hair-like ventral setae can be used as a supporting 

 character to separate genera and species. 



The relative lengths of the various structures of the genital segment show consider- 

 able differences, usually on the generic, but also on the specific level. The following 

 ratios were found useful : (i) length of penial sheath to body length, (ii) length of 

 basal rod to length of aedeagus, (iii) length of aedeagus to length of penial sheath, 

 (iv) length of aedeagus to length of basisternum. A finger-like membranous exten- 

 sion of the apex of the penial sheath is characteristic of the genus Ceroplastes. 



