Some Special Injurious Insects 



173 



ent wings. They almost always occur in colonies, 



frequently of immense numbers. They feed upon the 



leaves, buds, tender stems, and even the roots in some 



sorts of plants. They 



do much damage by 



sucking the plant j uices. 



Some species secrete a 



substance known as 



"honey dew," which is 



sought after by ants. 



The ants care for the 



aphis and protect them 



from the depredations 



of predaceous insects. 



The scale insects are 



somewhat allied to the 



plant-lice. The San 



Jose scale is the most 



serious representative of the many scale insects. (Fig. 100.) 



239a. Colonies of plant-lice may be found frequently on road- 

 side weeds, sometimes under the folded edges of leaves tended by 

 ants. Such a colony should be closely observed. Small tubes may 

 usually be seen on the abdomen of the lice. The ants have a way of 

 stroking the lice to make them give off the honey dew. This action 

 is often fancifully called "ants milking their cows." 



240. Insects Injurious to Stored Grain. The insects 

 that damage stored grain are the larvaB of moths and 

 beetles, and several species of weevils remotely akin to 

 the plum-gouger and cotton boll-weevil. Corn, wheat, 

 peas, and many other seeds are often damaged by these 

 insects while stored. Some species are very destructive. 

 The " grain- weevil" is the most destructive, particularly 

 to corn, peas, barley, kafir corn, etc. The two most 

 common species of weevil are shown in Fig. 111. The 



Fig. 110. The spring-grain aphis, a, wing- 

 less female; 6, larva; c, pui 



migrant. After Webster, 

 Department of Agriculture. 



a,, d, winged 

 nited States 



