No. 4.] BIRDS USEFUL TO AGRICULTURE. 49 



before night, as it had done before when I was watching it. 

 It was gone half an hour at one time." 



While this cannot be considered as proof that the downy- 

 woodpecker is a sapsucker, still, it shows that one bird cer- 

 tainly did take sap, though not from a fruit tree or in any 

 harmful quantity. Therefore, it seems probable that an 

 occasional individual of the same or allied species may have 

 the same habit, and that the only reason it has not been 

 observed before is that the birds have not been watched with 

 sufficient care. For the good they do, woodpeckers are 

 deserving all that they can ask at the hands of the farmers. 

 One useful trait of the downy woodpecker not generally 

 known is its feeding upon the woolly aphis, which is so often 

 seen on our apple trees. This has been observed by Mr. A. 

 H. Kirkland. Woodpeckers not only secure many wood- 

 boring insects which are injurious to trees, but they destroy 

 many eggs and hibernating pupae during the winter months. 



The Goatsuckers (Caprimilgidce). 

 These, represented in Massachusetts by the night hawk 

 and whippoorwill, are without doubt of great utility. Both 

 these species destroy such night-flying insects as the May 

 beetle, which is the parent of the white grub. They also 

 eat night-flying moths, so many of which escape diurnal 

 birds. Dr. B. H. Warren reports the whippoorwill as 

 feeding on potato beetles.* Dr. L. O. Howard sa^^s that 

 night-flying birds, such as night hawks and whippoorwills, 

 destroy the adult mosquitoes, f Mrs. Aaron, in the 

 ''American Naturalist," says that Harvey found six hundred 

 mosquitoes in the stomach of a single night hawk.| Unfort- 

 unatel}', these birds have been so hunted that there are now 

 few where once there were many. 



Swifts ( Mici'opodidce ) . 

 The swifts, of which our chimney swallow, so called, is the 

 sole example inhabiting this State, are believed to feed 



* "Birds of Pennsylvania," revised edition, 1890, page 180. 



t Dr. L. O. Howard: "The Mosquitoes of the United States," Bulletin 25, new- 

 series. United States Department of Ai^riculture, Division of Entomology. 

 X "American Naturalist," 1880, page 896. 



