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* 

 which a thorough system of irrigation would render comparatively- 

 harmless. 



This has been recognized by the prominent writers upon economic 

 entomology, and I may quote the words of my chief, Professor Eiley, as 

 follows : 



I have repeatedly laid stress in my writings on the importance of irrigation in com- 

 batting several of our worst insect enemies, and, aside from its benefits in this direc- 

 tion, every recurrence of a droughty year convinces me of its guarding against failure 

 of crops from excessive drought. I am glad to know that many farmers, and espe- 

 cially small-fruit growers in the vicinity of New York, are preparing in one way or 

 another for irrigation whenever it becomes necessary, and I was pleased to hear Dr. 

 Hexamer, at the late meeting of the American Pomological Society, urge a general 

 system of irrigation as the most profitable iavestment the cultivator can make in a 

 climate subject to such periods of drought as onrs is known to be. 



Perhaps the most striking example among this class of insects is the 

 Chinch Bug — a species which damages certain cereal crops to the extent 

 of upwards of five millions of dollars in years of abundance. This insect 

 is directly influenced by moisture and seldom occurs in numbers in the 

 more eastern States except after two or more successive seasons of 

 drought. After a year of excessive multiplication these insects will 

 often be found to have hibernated in immense numbers, and it is a well- 

 known fact that heavy rain-falls the succeeding spring will destroy them 

 almost completely. This being the case an artificial system of irrigation 

 will enable the agriculturalists to hold this insect completely in check, 

 and such a system as it is proposed to introduce in the West will render 

 the grain-growers of the reclaimed regions independent of the damage 

 which may be done by this insect and will enable them to compete on 

 most advantageous terms with the grain-growers of the more eastern lo- 

 calities, whose crops are occasionally subject to almost total loss by this 

 insect enemy. I may again quote from Professor Riley : 



Irrigation where it can be applied — and it can be in much of the territory in the 

 vicinity of the Rocky Mountaios, where the insect commits sad havoc, as with a little 

 eifort in many regions in the heart of the Mississippi Valley — is the only real availa- 

 ble practicable remedy after the bugs have commenced multiplying in the spring. I 

 wish to lay particular stress upon this matter of irrigation, believing, as I do, that it 

 is an effectual remedy against this pest, and that by overflowing a grain field for a 

 couple of days, or by saturating the ground after as many more in the month of May, 

 we may effectually prevent its subsequent injuries. — (Seventh Report Insects of Mis- 

 souri.) 



We may mention also the case of the Grape-vine Phylloxera and 

 may again quote from Professor Kiley : 



Submersion, where practicable, and where it is total and sufficiently prolonged, is 

 a perfect remedy. This is what even the closest student might expect, as he finds 

 that excessive moisture is very disastrous to the lice. M. Louis Faucon, of Graveson 

 (Bouchesdu-Rhone), France, has abundantly proved its efficacy, and has by means 

 of it totally annihilated the insect in his vineyard, which was suffering from it four 

 years ago. From his experience we may draw the following conclusions : 



(1) The best season to submerge is in autumn (September and October), when the 

 lice are yet active and the vines have ceased growing. Submergence for 25 to 30 

 days at this season will generally rout the lice. 



