equate answer, and, in a brief way, we may call attention to 

 certain such specific cases. 



METHOD OF INJURY. 



The injury done by insects to cultivated crops may, for 

 the present and in a general way, be considered as result- 

 ing from the insect's effort to get food. There are, un- 

 doubtedly, injurious effects to the plant frequently accom- 

 panying this food-getting effort that cause more damage to 

 it than can be laid to the mere loss of material taken by the 

 insect. However, the primary damage, from which these 

 other causes of loss spring, is done by the insect in feeding: 

 upon the plant. It therefore becomes of importance to 

 know just how the insect feeds, so that the character of the 

 damage may be understood and further, that economical 

 and practical means of control may be applied. The insect's 

 method of eating largely determines the character of the 

 control means to be used. Insects feed upon plants in one 

 of two ways, and on these feeding methods the whole series 

 of injurious insects can be divided into two great groups- 

 Either the insect that is causing damage to our crops has 

 biting mouth parts and obtains its food by eating out por- 

 tions of the attacked plant, from the fruit, the leaves, the 

 branches and trunk, or from the roots, or it has sucking 

 mouth parts and obtains its food by piercing the tissue of 

 the part of the plant attacked, and sucking the sap. These 

 two very different methods of feeding are readily recogniz- 

 able. The work of the leaf eating caterpillars, cut-worms; 

 the damage caused by certain leaf attacking beetles; the 

 feeding marks of grasshoppers upon twigs and branches; 

 the gnawing out done by mole crickets in Irish potatoes; 

 the burrowings and minings of various borers; these forms 

 of damage are v haracteristic of the work of insects with 

 biting mouth parts. It does not require a high degree of 

 expert knowledge to determine the facts as to eating meth- 

 ods in such cases as these, yet on these facts will depend, in 

 large measure, the method of control most likely to be 

 effective. On the other hand, we shall find that the meth- 



