i 4 4 MORPHOLOGY AND TAXONOMY OF ADULT MALES 



The ERIOPELTIS group can be regarded as being more specialized than the 

 next group, the EULECANIUM group. This conclusion is at variance with the 

 views of Borchsenius (1957), who held that they were the most primitive Coccidae. 



4. The EULECANIUM group : In this group the rest of the genera studied 

 have been included, i.e. Eulecanium, Nemolecanium, Physokermes, Rhodococcus, 

 Parthenolecanium, Phyllostroma, Filippia, Ctenochiton, Ericerus, Genus A and 

 Sphaerolecanium. There is little doubt that this group is a temporary assemblage 

 of genera, related to each other to a greater degree than to the three groups already 

 discussed. The relationships between these genera are very complex and until 

 more representative material has been studied in detail it seems best to treat them 

 together, although further subdivision appears to be inevitable. The heterogeneity 

 of this group of genera is reflected in the comparatively small number of characters 

 (about 25) that are common to all of them. Four of these are exclusive to this 

 group, namely (i) pleural sclerotization on the abdomen absent, (ii) fleshy ventral 

 head setae absent, (hi) posterior metasternal setae less than 4, and (iv) fleshy setae 

 absent posteriorly beyond abdominal segment III. 



All the genera included in the EULECANIUM group appear to be more primitive 

 than those of the other groups, especially the genera Eulecanium, Nemolecanium, 

 Physokermes, Rhodococcus, Palaeolecanium, Ericerus and Genus A. They have in 

 common the following characters, which can be regarded as being primitive : (i) a 

 scutellum which is not tubular, (ii) a basalare connecting the pleural wing process 

 with the episternum, (iii) a comparatively less specialized metathorax with the 

 episternum and metapleural ridge well developed, the latter with a vestigial pleural 

 wing process which supports the haltere, which is in turn connected to a small 

 suspensorial sclerite, (iv) the absence of prominent caudal extensions on abdominal 

 segment VII, (v) the absence of prominent caudal extensions with a cicatrix on 

 abdominal segment VIII. Furthermore, three of these genera namely Eulecanium, 

 Nemolecanium and Physokermes share a sixth primitive character in possessing small 

 tergites and sternites on all abdominal segments (this is also shared by Phyllostroma). 

 The other four genera share some of the above-mentioned characters, though not all 

 of them. All the genera except Physokermes, Palaeolecanium and Sphaerolecanium 

 share an additional feature which is probably primitive, i.e. having more than 4 

 simple eyes. 



Of the genera in this group, Sphaerolecanium appears to be the most specialized. 

 In this genus the scutellum is tubular (though the ventral foramen is large), the 

 halteres are absent and the metathorax reduced, the caudal extension of the VHIth 

 abdominal segment forms a prominent cylindrical lobe, and only 4 eyes are present. 

 This genus might be regarded as linking the EULECANIUM group with the 

 ERIOPELTIS or COCCUS groups. 



If relationships are estimated by calculating the total number of characters 

 shared by pairs of genera it appears that the genera Eulecanium, Nemolecanium, 

 Physokermes, Rhodococcus and Palaeolecanium are very closely related, with pairs of 

 genera sharing between 75 and 85 characters. Phyllostroma also comes close to 

 this group, especially to Palaeolecanium. The two genera Filippia and Ctenochiton, 



