26 Bulletin of the New Yoke State Museum. 



2. The strongest applications that may with safety be applied, 

 would be so impaired in strength in entering and penetrating the 

 ground as to become inefficient at a moderate depth.* 



3. The grub has the ability of withdrawing itself from the 

 obnoxious application by burying itself deeper in the ground. 



In consideration of the above and like difficulties, effort should 

 be directed toward the discovery of some substance which will act 

 upon the grub through other means than its exceeding strength. 

 Should it be of such a character as simply to be repulsive to its 

 taste, there is reason to believe that, rather than to feed upon roots 

 that are saturated with it, it would die of starvation. In this 

 manner, perhaps, may be found the reputed efficacy of the bur- 

 dock infusion and of the application next to be noticed. Experi- 

 ments in this direction are very desirable. 



Salt. — The application of salt has been pronounced an effectual 

 remedy, while it has also been said to be of no aA^ail whatever. 

 The remedy would be so simple, and withal so inexpensive, that 

 the claim made for it should be tested by careful experiments. It 

 is possible that the reputed success may have resulted from its 

 employment in the year of the greatest ravages — that preceding 

 the transformation to the beetle, for during this latter year (next after 

 the application), the newly-hatched grub will have made so little 

 progress in its growth that there would necessarily be a com- 

 parative immunity from its injury. On the other hand, the 

 ascribed failure may have followed a too economical use of the 

 cheap material — perhaps through fear of injury to the crop. 

 A gentleman ^who strongly recommends this remedy, presumably 

 from having thoroughly tested its value, deems it essential 

 that the salt should be used in large quantity. He writes : 

 "The great error with those who have used it with unsatis- 

 factory results has been its scanty application. I can assure the 

 reader that grass or potatoes will grow luxuriantly under an appli- 

 cation of one ton and a half p&>* acre, which quantity would be sure 

 to result in the complete extermination, not only of the grub, but 

 every other kind of worm, and prevent the scab and other excres- 



* Some of the Lachnosterna grubs ordinarily feed at a considerable 

 depth. Thus the larvas of Polyphylla decemlineata Say, has been found by 

 Mr. Eivers at a depth of from one foot to two feet among the root-fibers of 

 a coarse grass and roots of a Californian laurel, Umbellularia Califomica 

 {Bull. Gala. Acad. Sci., 1886, ii, p. 69). 



