COCCIDM 135 



resemble the lobes. The incision of the margin by their 

 shape and extent afford characteristics of value. 



Spines on the lobes are commonly present and aft'ord quite 

 serviceable characters. There are generally two for each 

 lobe — one on each of the dorsal and ventral surfaces. In some 

 cases these spines are tubular and threads may sometimes 

 be seen issuing from them. 



The plates are distinctly modifieil spines. They are gf^n- 

 erally flattened and frequently notched. The simi)le forms 

 differ from spines in that they do not have a globular base. 

 Wax ducts a])i)ear as hairs on spines which extend into the 

 body. 



Chionaspis Salicis. — The willow scale {Chiomispis salicis) 

 possesses a, dense waxy structure overlying and separate 

 from the body of the insect. The mouth parts are imbedded 

 in the bark and saj) wood. The head is pretty well marked 

 but antenupe and legs are reduced. There are two entirely 

 different kinds of scales on the willow. The larger is an oval, 

 somewhat elongated scale, the smaller narrow and with 

 three rather fine ridges. The large scale is the female, the 

 smaller the male. The growth of scales takes place during 

 summer months; they increase in size by successive moults. 

 As the larval scale is shed it is left attached to the new scale, 

 and so on, often two or three are attached to the outer sur- 

 face of the scale. By autumn these will have reached 

 maturity, and mating will occur prol)ai)ly by early October. 

 The males all die off" immediately and the females deposit 

 eggs and then shrivel u}) and die before winter. The female 

 never leaves the scale at all. 



At the beginning of winter there is tiiis mass of eggs 

 protected under a scale as the means of carrying the insect 

 over to the spring. They hatch probably during early Jime, 

 possibly the latter part of May. Eggs are reddish-purple. 

 The larvffi crawl from under the scale and scatter out and 

 make a special effort it would seem to get on new twigs and 

 fresh growth of wood. They seem to travel upward in the 

 lightest direction and this naturally carries them out to the 

 ends of the twigs and leaves. Diu-ing this migration period, 



