72 



Bureau of Farmers' Institutes. 



Old fruit enemies. — Apple tree bark louse, Mytil&spis pomorum. 

 The general form of the brown scale of this insect is nicely shown 

 at a in figure 4 and were we to examine infested trees in winter 

 we would find under the old scales large numbers of tiny white 

 The scurfy bark louse, Chionuspis furfiirus, is represented 

 The common name is descriptive of the white, 



eggs 



at h in figure 4 



Fig. 4 Scale injects: a apple tree bark louse; b sciirfj- bark louse; c San Jos6 scale d male 

 Of same; e English oyster scale; /Putnam's scale (original). 



scurfy condition of badly-infested trees. On breaking away the 

 protecting scale in winter numbers of purplish eggs may be 

 found occupying the scale cavity. The winter is passed by both 

 species in the egg stage. About June 1st the young appear and 

 may be seen crawling in large numbers over the trunk and limbs 

 of the infested trees. Either of these scale insects can be kept 

 under control by spraying the young with a contact insecticide 

 like whale oil soap solution, kerosene emulsion, the formulas for 

 which are given at the close of this article. 



San Jose scale. — The most important pest represented in figure 4 

 in this species, Aspidiotus perniciosus. Figure 4c represents the 

 female scale and at d the male scale is shown. Observe the round- 

 ness of the ash-gray scale, the central nipple and the lighter ring 

 surrounding it. The adult female scales are frequently consider- 

 ably larger and of a yellowish white color. The scale covering 

 these insects is quite variable, and it requires considerable experi- 

 ence to enable one to distinguish with surety between this species 

 and certain closely related forms and even then the entomologist 

 frequently prefers to take the trouble to make a mount for the 

 microscope and study the insect itself before passing on the iden- 

 tity of the species. A closely related form is Aspidiotus ancylus 



