often occur in enormous numbers, as many as 200 having been 

 found in an area covering a little over a square foot, feed upon 

 the roots of various plants. ... In feeding, these larvae move 

 about in the ground quite freely, as is evidenced by the small 

 molehill-like ridges they leave in going from plant to plant, 

 just under the surface of the ground. They "(Tipula infus- 

 cata (a kind to appear as adults in October)" become full- 

 grown about the middle of July, form perpendicular cells about 

 three to four inches underground when they pupate (p. 127), 

 The pupa then by means of the abdominal spines works its way 

 to the surface from which it protrudes two-thirds of its entire 

 length" (p. 128). "The adults . . . are about in great numbers 

 among the tall, rank grass, clover and weeds, from which they 

 rise awkwardly as one approaches, flying but a few yards be- 

 fore alighting" (p. 126). 



Natural enemies, at times at least, manifestly do not 

 amount to anything, else we would not have cases of nearly 

 200 larvae to the square foot. However, the Bureau of En- 

 tomology on page 129 gives a list of 86 kinds of birds that, ac- 

 cording to the findings of the Bureau of Biological Survey 

 feed on Tipulidae or their eggs. Among the larger birds thus 

 feeding there are varieties of jays, blackbirds, cukoos, and, one 

 kind each of nighthawks, woodpecker, grouse, snipe and gulL 

 The inference then simply is that these birds, and other birds, 

 under primitive conditions readily hold the pest in check, but 

 that with most of the lands given over to agriculture the birds 

 do not find even at best the necessary favorable conditions to 

 multiply sufficiently to keep the vast areas protected. 



