THE NEW MEXICO RANGE CATERPILLAR. 95 



gap that it might make in the ranks of the invading hordes would 

 soon be closed by successive broods that would appear in unburned 

 sections. 



INTRODUCTION OF NATURAL ENEMIES. 



The matter of the introduction of parasitic insects for control of 

 the Hemileuca will probably be investigated further. 



The importation of birds to feed on the caterpillars has been sug- 

 gested, but in the infested regions the wide treeless plains afford but 

 little encouragement for nesting birds. Besides this, it is a lament- 

 able and criminal fact that in spite of laws that are designed for the 

 protection of bird life in New Mexico, a constant and indiscriminate 

 slaughter of all sorts of birds is in perpetual progress until the com- 

 panionable species and those of high economic importance have been 

 practically exterminated in many parts of the Territory. This con- 

 dition of things may possibly account, in some measure, for this 

 Hemileuca invasion, and may in the not remote future bring into 

 prominence other insects now few and harmless, but multiplying 

 because their bird foes have perished at the hands of the hunter. 

 This bids fair to become a serious matter, and not alone in New 

 Mexico. 



ROLLING THE GROUND. 



Rolling the surface of the country to crush the larva? has been 

 suggested, and even using some sort of oil-burning apparatus that 

 would surely destroy all the eggs or larvae within a given area. 

 The roller has never been tried in an actual experiment, but it is 

 obvious to one familiar with the region that the surface is too uneven 

 to justify hopes for the destruction of more than a small percentage 

 by this method. 



THE CHIEF DIFFICULTY IN APPLYING REMEDIAL MEASURES. 



Another and more serious objection to any scheme of destruction 

 that involves either labor or expense is found in the extremely small 

 value per acre of the grass crop. When land rents for from 2 to 5 

 cents per acre for the year's pasturage it would not be reasonable to 

 expect any party interested to expend a very large sum per acre, 

 even to destroy a range pest. The aggregate damage resulting from 

 the attack of the range worm is enormous. But such large areas 

 are involved that when the loss is reduced to the acre unit it seems 

 entirely out of the question to the large ranch owners to involve 

 themselves in any method that aims to destroy the range worm by 

 expensive means. From their standpoint, it would be better to go 

 out of the cattle business and let the worms take the range than 

 to spend the income of a series of years in a doubtful experiment. 



