468 



Bulletin No. 116. 



[Avigust, 



November 22, the last of the above dates, most of these grubs 

 were from 7 to 14 inches below the surface; but one was found only 

 3 inches down, seven had stopped at a depth of about 6 inches, and 

 three had gone to 20 to 23 inches below the surface. The ground 

 did not freeze permanently until several days after this date. 



The grubs approach the surface in spring when the frost leaves 

 the ground and the soil becomes fit to plow, and one often sees in 

 the bottom of the furrow the tubular burrows made by them in 

 coming up from their winter quarters. 



Principai, Enemies. 



Swine. — Pigs are by far the most destructive enemies of white- 

 grubs and of May-beetles. They are extremely fond of these insects, 

 and of all others within their reach which are large enough to at- 

 tract their attention, and the diligence with which they will tear in 

 pieces the sod of an infested pasture, and the depth to which they 

 will dig in pursuit of grubs in cultivated ground are matters of 

 common observation. They will also search out and destroy the 

 May-beetles in May and June if allowed to range over pastures and 

 meadows where these insects hide by day and to which they resort 

 to lay their eggs. Pigs are conseqaently our most useful agents for 

 the destruction of these insects — a point which will be more fully 

 discussed in this paper under "Measures of Prevention and Rem- 

 edy." 



Crows and Blackbirds. — Next to pigs the most efficient destroy- 

 ers of white-grubs among our common larger animals are crows 

 and crow-blackbirds, both of which eat them greedily where they 

 can find them in sufficient numbers to make them an important ar- 

 ticle of food. Evidence on this point is less positive "with respect to 

 crows than concerning blackbirds. Mr. W. B. Burrows of the U. S. 

 Department of Agriculture, who has studied the food of the com- 

 mon American crow by examining the contents of more than a 

 thousand stomachs, reports that he has found white-grubs in a com- 

 paratively small number of these stomachs, but that May-beetles had 

 been eaten by very nearly all the crows taken at a time when these 



