Plants as Affected by Animal Parasites. 177 



Any light wood frame, covered with cloth may be used 

 as a substitute for the more convenient device shown 

 in the figure. Where the substitute is used, the beetles 



must be looked for on 

 the sheet and de- 

 stroyed as found. 



315. The Prompt 

 Destruction of Iti- 

 fested Fruit mate- 



FiG. 76. Curculio catcher. It is wheeled . ,, ., . , 

 beneath the branches of the tree, and rialJy aids in KCep- 

 the latter are struck with a light, cloth- . . , 



covered mallet, which jars the beetles ing the iruit-bur- 

 upon the sheet-covered frame, from 



which they roll into the box beneath, rowing insects in 

 For small trees, the trunk slips in 

 through the slot at the left. subjection. H O g S 



and sheep in the orchard are most valuable assistants in 

 this work. The apple-maggot* is more effectually con- 

 trolled in this manner than by any other known method. 



316. Sucking Insects include many species. They 

 feed on the juices of the plant which they infest, and 

 do not directly devour its tissues, as do the eating in- 

 sects; but they reduce its vitality by their continual 

 drain upon the reserve food. The so-called scale in- 

 sects belong to this class. These are especially difficult 

 to destroy, since they are dormant the greater part of 

 the year, and in this condition are protected by their 

 comparatively resistant scales. 



Sucking insects are not susceptible to poisonous in- 

 secticides, hence we must resort to materials that clog 

 their breathing pores, as kerosene (294), that dissolve 

 their eggs and scales, as potash solutions or that form 



* Trypela pomonella. 



