DiaspincB. 29 



in the genera ^^;//^z« and Fiorinia it is greatly enlarged, the female 

 insect attaining its greatest dimensions during this second stage 

 (//. I. figs. 2, 3). 



The adult female varies considerably in form in different genera 

 and even species. The body is either discoidal as in many species 

 o{ Aspidiotiis, more or less oblong as in Chionaspis, or linear as in 

 hchiiaspis and some forms of Mytilaspis. The skin usually remains 

 soft and flexible throughout the adult stage, though in some few 

 species it becomes highly chitinised and indurated. 



It is probable that this final stage really represents the pupa, 

 the further development of the female insect being suppressed, 

 although the reproductive system is complete. It is certain that 

 this is the stage corresponding with the true pupa of the male 

 insect. 



As in the previous stage, there is no vestige of the limbs and 

 the antennae remain only in the form of minute setiferous tubercles 

 {pl.l.fig.ii). 



The spiracles are in two pairs, opening on the under surface. 

 They have usually an intersegmental position, between the head 

 and prothorax and the mesothorax and metathorax respectively, 

 though they probably belong to the hinder segment in each case. 

 The anterior pair is frequently situated close to the rostrum ; the 

 openings of the second pair are usually more widely separate. 

 The anterior stigmatic orifices are often — and more rarely the 

 posterior pair also — associated with a small group of glandular 

 pores known as the parastigmatic glands. 



The rostral apparatus, which is ventrally situate at a point near 

 the middle of the cephalothorax, consists of a complicated chitinous 

 piece forming the rostrum, which probably represents a fused 

 clypeus and labrum {fig. 10, U), and a small conical mentum {fig. 

 10, c), which in this family is invariably of a single joint (mono- 

 merous). The four long curling setae {fig. 10, e), which together 

 form the sucking-tube, arise from the rostrum and pass along a 

 channel on the upper surface of the mentum, emerging at a point 

 near its extremity. The rostral setae are considered to represent 

 the maxillae and mandibles of the insect. They can be withdrawn 

 into the body, when they lie in a loop which extends into the 

 abdominal parts of the insect. In prepared specimens two of the 

 setae usually become separate, while the other two remain in close 

 contact. For a more detailed description of the parts of the 

 rostrum Dr. Berlese's excellent work should be consulted. 



