40 N.S. ENTOMOLOGICAL SOCIETY. 



The females are wingless and usually stationary with head and thorax 

 united ; the males are usually provided with two transparent wings, have 

 no mouth and unlike the females undergo a complete metamorphosis. 

 In nearly all forms the tarsus has but a single segment provided with a 

 single claw. 



Most scale insects are oviparous, but a few, e. g. the San Jose Scale 

 (Aspidiotus perniciosus) are viviparous. The female only produces young 

 once in a lifetime. The eggs may be protected by a waxy covering se- 

 creted by the female as in most of our common species, or by the body of 

 the insect itself, or in other ways. In their nymphal state, scale insects 

 are active, possess well developed antennae and the three pairs of legs 

 typical of insects. In this stage they are strikingly unlike the motionless, 

 legless females from which they spring. 



San Jose Scale. 



(Aspidiotus perniciosus Comst.) 



This insect has done so much damage throughout the fruit growing 

 districts of North America that its name is familiar to everyone. On 

 account of its very small size, however, it is seldom recognized by the 

 ordinary observer. 



Fig. 4. Female Scale. Fig. 5. Male Scale. 



When very numerous the insects form a greyish coating over the 

 bark, which, when examined with a magnifying glass, will be seen to be 

 composed of a large number of tiny bodies, circular in outline and about 

 the size of a pinhead. The scales are slightly raised and the female scales, 

 which are most numerous, have a nipple-like prominence in the centre. 

 The male scales are smaller than the females and with sides nearly par- 

 allel. The nipple-like prominence is at one side of the scale. 



