220 THE COCCIDAE 



siderable time, several months, the length of this stage varying 

 greatly with the species. When the insects of this stage molt, 

 there is no variation in the way in which the cuticle ruptures, but 

 in all species there is a transverse rupture on the ventral aspect 

 cephalad of the rostrum which connects on each side with the 

 lateral margin, the further rupture of the cuticle extends caudad 

 along each side to the pygidium. The ventral portion of the 

 exuvia is rolled back upon the caudal portion of the ventral aspect 

 of the body. 



The females at the completion of the second nymphal stage 

 and after the second molt assume the adult condition. The most 

 striking variation found in the adult female from that of the 

 second nymphal stage is the great increase in size and the greater 

 complexity in the structure of the caudal portion of the abdomen. 



The male of the second nymphal stage is similar to the same 

 stage of the female. It lacks both legs and antennae, but possesses 

 a rostrum and rostralis. At the second molt all similarity between 

 the male and female is lost and the males of the third nymphal 

 stage are elongated. The rostrum and rostralis are wanting and 

 the developing legs and antennae have become of such size that they 

 show externally, each enclosed in a cuticular sac. The male 

 nymphs during this stage because of their similarity to the pupae 

 of insects with a complete metamorphosis are often incorrectly 

 designated as pupae and those of the second stage as propupae. 

 The third nymphal stage requires only a few days for its comple- 

 tion and after the final or third molt the insect transforms to an 

 adult. 



The adult males, after completing their nymphal development, 

 push the exuvia of the last molt out under the margin of the scale 

 and the fully formed insect normally remains for several days 

 under the scale. This is evidently for the further completion of 

 the development of the adult organs. The wings are fully ex- 

 panded during this time. 



The completely formed male is very different in appearance 

 from the adult female. The constrictions separating the segments 

 of the body are distinct. The eyes are simple and six in number, 

 four dorsal ocellanae, two of which are large and subequal in size 

 to the two ventral ocellanae. The antennae are typical in form 

 and consist normally of ten segments. The thorax is characteristic 

 in form and bears the nine-segmented abdomen. The stylus is 

 long and pointed, often one-half or more the length of the abdomen. 



