Diaspince. 2 5 



the rupture occurring on the under surface of the head at a point 

 between the antennae and the rostrum, the antennae remaining 

 attached to the anterior margin, while the rest of the ventral parts, 

 with the limbs and rostral apparatus, are pushed back to the 

 posterior extremity {pi. I. fig. 9). This character will be found of 

 assistance in determining some doubtful cases. When the male 

 puparium is unknown, it is sometimes difficult to decide whether 

 a particular species should be assigned to the genus Aspidiotiis or 

 Diaspis. If upon examination the larval pellicle is found to consist 

 of the dorsal parts only and no antennae are present, the insect 

 may with confidence be placed under Aspidiotus. But, if, on the 

 contrary, the antennae are found to be still attached to the anterior 

 margin of the pellicle, the insect may be considered a Diaspis. In 

 all cases the harder dorsal parts retain their original form and 

 position. 



So far the puparia of both sexes have undergone a similar 

 development ; but from this point they diverge. With the first 

 moult the insect has discarded its limbs and assumed a pupiform 

 state, which in the case of the female is retained, with some 

 modification, during the rest of its life. It will be convenient to 

 follow the development of the female puparium first. 



After shedding the first skin the insect rapidly increases in 

 bulk, so that its soft body can no longer be protected or concealed 

 by the larval scale. To supply the deficiency, it extends the 

 margin of the discarded pellicle by the addition of a thin mem- 

 brane-like material composed of closely woven filaments secreted 

 by special organs (to be described later) situated on the terminal 

 segments of the body. This thin covering-scale keeps pace with 

 the growth of the insect. At the approach of the second and last 

 moulting period, the dorsal parts of the body become more rigid 

 and horny, the skin splits as before, the pellicle remaining in 

 position attached to the dorsal scale, and the insect assumes its 

 final stage, which does not differ very greatly in external characters 

 from the preceding one. 



There are not the same differences in the mode of shedding 

 the second pellicle that were noticeable at the earlier ecdysis. In 

 all the genera the rupture occurs on the under surface in front of 

 the rostrum, and the ventral skin is pushed back to the posterior 

 extremity, where it remains attached to the hardened dorsal parts. 

 The adult female is at first concealed by the two discarded 

 pellicles, which are cemented together by the thin membranous 



E 



