OF THE FAMILY COCCIDAK 127 



being reduced to a greater or lesser degree in the ERIOPELTIS and INGLISIA 

 groups, but complete in the COCCUS and EULECANIUM groups ; the absence 

 of the lateral arms separates E. Pfestitcae from all other species. The dorsal part of 

 the midcranial ridge is frequently absent or vestigial and in the latter case it can 

 usually only be seen in well stained preparations, thus it is not particularly useful, 

 but apparently operates on the specific level. The postoccipital ridge, which pro- 

 vided a series of characters in the Diaspididae (Ghauri, 1962), is absent in this 

 family. The absence of reticulation on the median crest is peculiar to two genera of 

 the EULECANIUM group. The degree of development of the postocidar ridge 

 separates groups of genera, genera and species in so far as it (i) is generally weak 

 and tapering dorsally, but strong in the COCCUS group and the genus Eriopeltis, 

 (ii) usually forks below the ocellus, except in the ERIOPELTIS group and (iii) is 

 reduced posteromedially in some species but not in others. A broad interocular 

 ridge is characteristic of the ERIOPELTIS group. The preoral ridge is absent in 

 the ERIOPELTIS group and two genera of the EULECANIUM group. The 

 size of the cranial apophysis and the shape of its apex show some variation which 

 can be used at the generic and specific level. The number of simple eyes is a very 

 distinct and useful character. In the ERIOPELTIS and COCCUS groups the 

 number is constant (4), but in the EULECANIUM group the number varies from 

 4-10, separating genera. Thus four closely related genera, Eulecanium, Nemole- 

 caninm, Physokermes and Rhodococcus can easily be separated in having 10, 6, 4 

 and 8 eyes respectively. This character was suggested to be of generic importance 

 by Newstead (1903), and Sulc (1908) when he defined the genus Eulecanium Ckll. 

 and his two new genera Sphaerolecanium and Palaeolecanium. The large size of the 

 lateral eyes is characteristic of the INGLISIA group. 



The setae of the head provide a number of important characters and their absence 

 or presence in various regions of the head can be used to separate groups of genera. 

 In the EULECANIUM and ERIOPELTIS groups there are no fleshy dorsal head 

 setae, no setae at all between and behind the ventral simple eyes and no genal 

 setae ; in the EULECANIUM group there are also no fleshy ventral head setae. 

 In the INGLISIA and COCCUS groups there are present fleshy dorsal head setae as 

 well as fleshy ventral head setae, setae between and behind the ventral eyes, and 

 setae on the genae. The number of setae varies individually, but the differences 

 in the ranges of individual variation can be used to separate some species and 

 genera. 



The antennae provide a number of characters which can be used at the generic 

 and specific levels. These are (i) the length of the antenna in relation to the length 

 of the body, the posterior leg and the penial sheath, (ii) the width of the 2nd segment 

 relative to that of the 1st, (iii) the length of the 3rd segment in relation to its width, 

 (iv) the relative lengths of the 3rd and 10th segments and (v) the shape of the 

 terminal segment. In addition the relative length of the fleshy setae and the antennal 

 bristles, and also the number of subapical setae can be used to separate 

 genera. 



