156 
Date 
Averag-fc Grubs 
per Square 
Range in Depth 
Average Depth 
Oct. 3,1905.... 
Oct. 10, 1905 
Oct. 23, 1905.... 
Oct. 31, 1905.... 
Nov. 22, 1905.... 
29.2 
22^6 
25.3 
22. 
24.75 
Near surface to 8 in. 
Near surface to 10 in. 
Near surface to 10 in. 
Near surface to 16 in. 
Three in. to 23 in. 
3.5 
3.1 
3.1 
6.4 
10. 
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. 
Principal 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 consequently 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." 
Crozvs 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 
