76 



THE SCALE INSECT IN NEW HAMPSHIKE 



ger. The presence of sucli a layer indicates that the saj) from 

 the bark is being sucked out by millions of the insects and that 

 the health of the tree is being seriously impaired. 



The scales that are found through the winter develop in early 

 spring into mature insects that give birth to many young scale 

 lice. These are tiny whitish or yellowish white creatures that 

 crawl about over the bark for about thirty hours before they 



finally fasten themselves to 

 it, inserting their curious 

 beaks to suck the sap. They 

 then begin to secrete the 

 scale which is so charac- 

 teristic of this family of 

 insects. Certain definite 

 stages have been observed 

 in the formation of this 

 scale. At first there is a 

 white or fluffy stage due to 

 the secretion of cottony 

 threads; then a tufted stage 

 due to waxy threads; then 

 a black stage during which 

 the scale becomes thicker, 

 and finally passes into the 

 mature form. These are 

 the periods of the female 

 scales. The male scales 

 finally develop into minute two-winged creatures which are able 

 to fly about. 



When the San Jos6 scale occurs upon older trees it is most 

 likely to be found on the twigs and smaller limbs, but upon 

 young trees it may occur over the whole surface. But it does 

 not confine its attacks to the bark, for the leaves and fruit are 

 often infested; upon the young bark and the leaves and fruit 

 there is a very characteristic purplish ring around each scale. 

 When the leaves are infested the insects are likely to be found 

 along the midrib. 



This pest is most likely to be introduced into new localities 

 upon nursery stock imported from infested regions. This is 

 believed to be the way in which it was first brought to the 

 Eastern states. It is also likely to be carried upon apples and 



Fig. 2. 'San Jose Scale: Apple Branch, with 

 scales — natural size ; enlarged scales above, 

 at left (after Howard). 



