446 INSECTS INJURIOUS TO VEGETATION. 



Admitting the Eurytoma to be the sole cause of the mischief, 

 the following suggestions will be found useful in arresting its 

 ravages. As the disease is seated mostly near the base of the 

 straw, in or near the second or the third joint, the greater part 

 of the diseased portions will be left in the stubble when the 

 grain is reaped. Most of the insects remain unchanged in the 

 stubble till the following year. If, then, we can destroy the 

 maggots in the stubble before they have acquired wings and 

 made their escape, we shall, in great measure, restrain their fur- 

 ther propagation and increase; for it is in the winged state 

 alone that insects propagate their kind. It has been found in 

 Massachusetts that ploughing in the stubble has little or no 

 effect upon the insects, which continue alive and uninjured 

 under the slight covering of earth, and easily make their way to 

 the surface when they have completed their transformations. 

 The only practicable method of destroying the insects is to burn 

 the stubble containing them. All the straw and refuse, which 

 is unfit for fodder, should likewise be consumed, because it will 

 be found occasionally to contain a small amount of diseased 

 portions of the straw. Some of these may remain among the 

 grain itself, being too heavy to be separated by the process of 

 winnowing. These will have to be picked out by hand. 

 Moreover, as some few of the insects are transformed to files 

 during the first summer, and these will suffice to continvie the 

 race, it becomes important that all the means above recom- 

 mended should be continued during several successive years; 

 and when these are universally, carefully, and thoroughly put 

 in practice, they can hardly fail to exterminate the Eurijtoma. 

 A free use of manure and thorough tillage, by promoting a 

 rapid and vigorous growth of the plant, may render it less 

 liable to suffer from the attacks of the insect. Large fields, 

 well seeded, will probably escape better than those that are 

 smaller and thinner sown, in which the insects, when about to 

 lay their eggs, can penetrate easily and to a greater distance. 



