1XSECT PESTS AND DISEASES, 



181 



This freezes in the crevices of the bark, and when thaw- 

 ing, brings away all insects, together with eggs that may 

 be sheltering there. During summer, should the trees be 

 infested, syringe them with soap-suds of the above strength, 

 to stupefy the insects upon the leaves and shoots, and 

 follow up the application with a mixture of Gishiirst 

 compound and tobacco-water. 



PEAR OYSTER-SCALE (Diaspisostreaformis*), Fig. 53. The 



FIG. 53. PEAK OYSTER-SCALE. 



damage done by this insect (which is peculiar to the pear) 

 is similar to that caused by the mussel-scale to the apple. 

 The latter also attacks the pear to a slight extent. The 

 name oyster-scale refers to the covering of the female 

 insect being like an oyster-shell on a small scale. Under 

 this the legless, yellowish-white, maggot-like female lives, 

 and feeds upon the shoots by inserting her proboscis into 



