i68 



THE STUDY OF INSECTS. 



Mealy Bugs are the most common and the most noxious of 

 green-house pests ; and in the warmer regions, as in Florida, 

 they infest plants in the open air. Two species are shown 

 greatly enlarged in Figures 204 and 205. These insects are 

 extremely difficult to combat, as the white powder with 

 which the body is clothed protects them from the sprays 

 and washes ordinarily used. 



Kcnncs. Species of this genus are common upon oaks 

 wherever they grow. These insects are remarkable for the 

 wonderful gall-like form of the adult females. So striking is 

 this resemblance, that they have been mistaken for galls by 

 many entomologists. Figure 206 represents a species of this 

 genus upon Qucrcus agrifolia. The gall-like swellings on the 



stem are the adult females 

 are the immature males. 

 Orthezia (Or-the'zi-a).- 



the smaller scales on the leaves 



genus 



The members of this 

 occur not uncommonly on vari- 

 ous weeds. They are remark- 

 able for the calcareous secretion 

 with which the body is clothed. 

 This is in the form of lone 



o 



plates. Figure 207 represents 

 a nymph ; in the adult female 

 the secretion becomes more 

 elongated posteriorly, and 

 forms a sac containing the eggs 



mixed with a fine down. Later 







when the young are born, they 

 remain in the sac till they have 

 themselves secreted a sufficient 



FIG. 207. Orthezia, enlarged. (From ^ n -, n ., nt - o f t ] 1p lamellar rnnf-t-f-r 

 the Author's Report for iSSoj "<ll 



to cover them. 



Pulrinaria (Pul-vi-na'ria). This genus includes species 

 in which the body of the female resembles Lecanium, de- 

 scribed below, but which excrete a large cottony egg-sac. 

 This egg-sac is not ribbed, but is of the form shown in 



