I 
560 HYMENOPTERA. 
amount of property that is at stake, and the serious losses 
already sustained by the ravages of the joint-worm, render 
it necessary to ascertain the true history of the insect be- 
fore proceeding to take measures for the protection of our 
crops. We are to consider, in destroying the Eurytoma, 
whether we shall kill an enemy or a friend. If it be a 
parasite, as the almost universal opinion of entomologists 
would lead us to believe, it would be the height of folly 
to attempt to interfere with its operations. On the other 
hand, if we can show it to be a plant-eating insect, we 
may use such means as arc in our power towards checking 
its career, not only with perfect safety, but with eminent 
advantage. In this case, in dealing with the joint-worm, 
we need not be restrained by the consideration that the 
diseased straw contains also some truly parasitical larvae; 
for these, as already stated, are very few in number com- 
pared with the immense swarms of the Eurytoma that are 
annually produced. If we can succeed in exterminating 
these destroyers, we shall have no occasion for the services 
of the parasites. 
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 further 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 con- 
tinue alive and uninjured under the slight covering of earth, 
and easily make their way to the surface when they have 
completed their transformations. 
