SONG BIRDS OF ORCHARD AND WOODLAND. 203 



lice and their eggs, house flies and other diptera, and a very 

 few hymenopterous flies. I can only add to this the fact 

 that I have seen this species feeding on the woolly apple tree 

 aphis (Schizoneura lankfera) in late October and early No- 

 vember, after all the birch plant lice, of which these birds 

 are very fond, had disappeared. This apple tree aphis is a 

 particularly destructive species, Avhich has done great injury 

 in the past. Young trees are frequently injured b}^ these 

 aphids, which also attack the roots and the new growth 

 on older trees. As spring approaches, the Myrtle Warbler 

 feeds less on berries and seed, but eagerly hunts the early 

 flies, moths, and gnats that appear on warm days in sheltered 

 swamps and along water courses. It now ])ecomes of great 

 service to orchard and woodland, for large flights of these 

 birds move slowly northward through the State, feeding- 

 very largely on the tree pests that develop with the open- 

 ing foliage. 



VIREOS. 



The Vireos all normally seek orchard, woodland, or swami)y 

 thicket. The three species, however, that breed commonly 

 in the greater part of Massachusetts, have all learned to nest 

 about the habitations of man. They perform an economic 

 service similar to that rendered by the AVarblers, except that 

 during summer they feed to a greater extent upon wild fruits. 

 They live mainly among the foliage, and in action much re- 

 semble Warblers, except that, being heavier in build, their 

 motions are usually more deliberate. The Solitary Vireo 

 and the White-eyed Vireo breed here, but only uncommonly 

 or locally. The latter is common in some places near the 

 coast, but I have found it in only a few favored localities in 

 the interior. The Solitary Vireo is regarded as rare in the 

 breeding season, but it probal)ly breeds in nearly all the 

 counties in most seasons. It may be present in a certain 

 piece of woods during one breeding season and absent the 

 next, and is sometimes fairly common in considerable areas 

 in some counties. 



