72 



The alfalfa crop is a very profitable one aud easily grown with irrigation and has 

 been very extensively planted, the fields devoted to it covering many thousands of 

 acres. 



The injury to this crop is of such a nature that I believe practical remedies may 

 be adopted, and. as will be stated later, active measures should be adopted this fall and 

 next spring. 



THE AMOUNT OF INJURY. 



The great loss this year has resulted from the destruction of the seed crop. In many 

 fields this has has been a total failure, and the loss may be considered as covering thou- 

 sands of acres and involving many thousands of dollars. One man who had something 

 over 100 acres in alfalfa considered that his loss amounted to about $2,000. While he 

 expected to cut and use the crop for hay, the damage had been such that the hay would 

 •be little better than after the seed crop had been secured, and he reckoned the full loss of 

 the seed crop for the season. In some cases farmers were cutting for hay when they had 

 intended to allow the crop to go to seed, and in this way were reducing the amount of 

 their loss by the value of the crop of hay cut early over what the hay would be worth 

 after maturing seed, the latter, of course, being much less valuable than the hay cut 

 before seed matures. In many cases the farmers had been ccpending largely upon the 

 crop of seed to help them out of debt, and the loss from the grasshopper injury falls 

 heavily upon them. 



THE SPECIES DOING THE DAMAGE. 



The Differential Locust is, I think, chargeable with fully nine-tenths of the de- 

 struction, both in alfalfa and orchards, and the reasons for its increase in this section 

 seem to be quite evident. The irrigated fields of alfalfa furnish it with favourite food in 

 abundance throughout the year, and have given it an opportunity to multiply rapidly 

 without exhausting its food supply. 



The ditches which traverse the fields and possibly parts of the fields themselves 

 furnish a most excellent location for the deposition of eggs, the ground being compact 

 and for the most part undisturbed throughout the year. That the eggs are deposited in 

 or alongside the ditches is indicated by several facts, though at the time of my visit the 

 locusts, while pairing, were none of them ovipositing. In the first place, the greatest 

 damage had occurred in strips on either side of the ditches, and only in the worst fields 

 extends over the entire field ; second, at the time of my visit the pairing individuals were 

 quite evidently collecting more particularlj'^ in these locations ; third, the testimony of 

 those who seemed to have observed most closely agreed in placing the greatest number of 

 young hoppers in spring along the borders of the ditches, a point which is clearly sup- 

 ported by the injured strips so plainly to be seen. No one whom I questioned had seen 

 the locusts in the act of ovipositing. 



The ditches contain no water during a large part of the year, and in fall the com- 

 pact bottom, which doubtless affords more moisture than the fields in general, would seem 

 an excellent place for the deposition of eggs, as well as the banks on either side. Judging 

 by the habits of these and allied species in other locations it would be hard to conceive 

 a more favorable place for the deposition of eggs, and it seems to me very probable that 

 this, as well as the suitability and abundance of the food, may be considered an import- 

 ant factor in the rapid increase of the species in the last three or four years, an increase 

 that has taken place directly with the cultivation of alfalfa by irrigation. 



It would seem also that this habit renders the insect especially open to attack, and 

 1 see no reason why concentrated effort may not entirely prevent a repetition of the 

 damage another year. 



MEASURES RECOMMENDED. 



The situation, it seems to me, is one deserving serious attention, but one which ofiers 

 every hope for successful work, if the residents of the affected localities can but be in- 

 duced to make a little effort at the proper time. 



