12 RELATION OF BIRDS TO COTTON BOLL WEEVIL. 



about the field, continue to stir or harrow the ground and thus give 

 the birds a chance to pick up the weevils as they are driven from 

 their hiding places. 



2. Destroy every stalk of volunteer or seppa cotton before planting 

 time. Investigations during the very mild spring of 1907 showed 

 clearly the folly of allowing seppa cotton to grow. The weevils 

 emerged early from hibernation and at once began to feed on the 

 sprouted plants, which were very numerous all over south Texas 

 and as far north as northern Louisiana. The birds were unable to 

 find the weevils readily after the latter had taken to the plants, and 

 hence large numbers survived until the new cotton was large enough 

 for them to feed upon. Had there been no seppa cotton in the fields 

 the weevils would have been exposed to the attacks of all ground- 

 feeding birds and their numbers would have been materially reduced. 



STATUS OF THE SPECIES OF BIRDS KNOWN TO EAT THE BOLL 



WEEVIL. 



SWALLOWS AND MARTINS. 



Six kinds of swallows occur commonly in Texas, and four are 

 known to eat the boll weevil. Since the habits of all the species are 

 essentially alike, eventually doubtless all will be found to feed on 

 the insect. Swallows are migratory, nesting in the United States 

 and wintering chiefly in Central and South America. Vast numbers 

 pass through Texas in September on their way to their winter homes, 

 and at this season they find many boll weevils in the air, where they 

 are easily captured. So abundant are the swallows and so marked 

 is their taste for boll weevils that they must be accorded very high 

 rank in the list of the enemies of this destructive insect. 



Cliff swalloic. — Cliff swallows, eaves swallows, or mud swallows, 

 as they are variously called, nest commonly in the northern and 

 western States and in the western portion of Texas as far east as Aus- 

 tin and Waco. They breed in colonies, and their pouch-shaped nests 

 of mud are plastered to the face of cliffs or stone walls or under the 

 eaves of barns. They are abundant over the greater part of Texas 

 during the autumn migration, and in September thousands pass over 

 the cotton fields every day. 



Thirty-five specimens were collected in the fall of 1906 and all but 

 one of them had eaten boll weevils, the majority having taken 

 nothing else. Many of the stomachs were crammed full of the 

 weevils. The largest number eaten by a single bird was 47, while 

 many others had taken from 20 to 30 at a meal. The total number 

 destroyed by these thirty-five birds was 638, an average of 18 weevils 

 to each bird. It is of course impossible to estimate with any degree 



