16 MORPHOLOGY AND TAXONOMY OF ADULT MALES 



Silvestri (1919a, 1919b, 1920), Sulc (1932) and Jancke (1955) ; it has been called the 

 chitinous apodeme (Pesson, 1941) and lateral arches (Borchsenius, 1957 ; Bustshik 

 & Saakjan-Baranova, 1962). 



Sometimes the pre- and postocular ridges are joined together below the ocellus 

 by a strong ridge ; this ridge has not been observed before and is here called the 

 interocular ridge (ior). Its presence is constant in a few species (the ERIOPELTIS 

 group ; Text-figs. 25, 28), where it is a broad ridge ; in one other species (Genus A ; 

 Text-figs. 20, C ; 21) its occurrence is irregular : it is very narrow if present, some- 

 times present on one side only and occasionally absent on both sides. On the 

 preocular ridge in I. theobromae (Text-fig. 30) a small posteriorly directed process 

 below the articular process apparently represents a rudiment of this ridge. The 

 homology of the interocular ridge and its possible relation to the conditions found 

 in the Pseudococcidae will be discussed later. 



The ocular sclerite bears a number of simple eyes and a pair of lateral ocelli. 

 The simple eyes comprise a pair of dorsal and a pair of ventral eyes, while 1-3 pairs 

 of additional lateral ones may be present. 



The dorsal eyes (dse) are situated on the anterolateral part of the head above the 

 bases of the antennae and are widely separated from each other. The ventral eyes 

 (vse) are located on the medioventral bulge close to each other in a submedian 

 position ; the area between the ventral eyes is somewhat raised (e.g. E. tiliae, 

 Text-fig. 3) or flat (e.g. L. luzulae, Text-fig. 28). The lateral eyes (lse) occur on each 

 side of the head, more or less in line with the dorsal and ventral eyes. The dorsal 

 and ventral eyes are usually large and subequal in size, while the lateral ones are 

 considerably smaller. Sometimes (I. theobromae, Text-fig. 29, 30 ; Ceroplastodes 

 chiton Green) the lateral eyes are only slightly smaller or as large as the others. 

 The corneae of all these simple eyes are circular, deeply produced into the head- 

 capsule and surrounded by a narrow membranous ring. The dorsal and ventral 

 eyes are always present and are the only ones which occur in the ERIOPELTIS and 

 COCCUS groups and some species of the EULECANIUM group (Text-figs. 24-43, 

 6, 10, 22) ; some other species have one (N. abietis, Text-fig. 4), two (R. spiraeae, 

 P. myrtilli, Ctenochiton sp., Genus A, I. theobromae ; Text-figs. 8, 12, 16, 20, 29) or 

 three (E. tiliae, F. viburni, E. pela ; Text-figs. 2, 14, 18) additional lateral eyes. 

 The lateral ocellus (o) usually appears as a weakly sclerotized spot on a membranous 

 bulge, which is somewhat conical in Eriopeltis spp. (Text-figs. 24, 26). It is situated 

 posterolateral to the dorsal simple eye, immediately anterior to the postocular ridge. 

 The structure of the eyes and their innervation in P. corni were studied by 

 Pflugf elder (1936). From his work it seems certain that the simple eyes on one 

 side represent the isolated facets of a single compound eye. He also claimed that 

 the lateral ocelli are persisting larval ocelli, a view already held by Putnam (1879) 

 and Moulton (1907). 



The large lateral bulge posterior to the postocular ridge corresponds to the gena (g). 

 It is weakly sclerotized and in most species it is distinctly reticulated (e.g. Eriopeltis 

 spp., Parthenolecanium spp. ; Text-figs. 24 & 26, 38 & 39). The sclerotization and 



