31 



BULLETIN OF 



Massachusetts Board of Agriculture. 



THE GYPSY AND BROWN-TAIL MOTHS. 



By A. H. KiUKLAND, M.S., Boston, Mass. 



Westward the course of insect damage takes its way. Civilization, 

 after all, has hard work to escape from some of its drawbacks. It is 

 unfortunate that in the westward march of mankind certain foes which 

 levy a constant and heavy tax on the products of the soil could not have 

 been left behind ; yet the agencies of commerce are subject to natural 

 laws, and in bringing to a new land the plants, trees and seeds of other 

 climes, have naturally brought also many of the insect pests of foreign 

 lands. Recently a nurseryman brought to Boston by accident a serious 

 scale insect of stone fruits. The elm leaf beetle was introduced at Bal- 

 timore in the early part of the nineteenth century in packings surround- 

 ing a lot of European elms. Within a few years a grower of Dutch roses 

 at Somerville, Mass., imported with his bushes the serious and annoying 

 brown-tail moth pest. These instances, tiiken at random, show the dan- 

 ger to which we are continually exposed by unrestricted commercial 

 activity. On the other hand, we have abundant evidence that nowhere 

 in the world has the subject of economic entomology received the atten- 

 tion or reached such a state of development as in our own land. This 

 potential knowledge has been particularly valuable in the case of warfare 

 against imported insect pests. 



Foes of this class are usually on a difterent basis than native species. 

 In its native environment a species is subjected to the balancing process 

 of nature. In other words, it feeds and is fed upon. It destroys the 

 foliage, perhaps, of some staple crop, and in turn is attacked by para- 

 sites, predaceous insects and birds. Its numbers may vary from year to 

 year, Vivit when it becomes over-abundant it immediately oftex's a larger 

 food supply for its natural enemies. They soon gain ascendency, the 

 host insect is reduced in point of numbers and its ravages may even 

 cease to be noteworthy. A knowledge of this shifting relationship, this 

 " balance of nature," is of importance since it underlies the problem of 

 dealing with all insect pests, jjarticularly those of foreign origin. 



Take the case of the gypsy moth for example. This creature was 

 brought here free from the controlling influence exerted by half a hun- 



