168 USEFUL BIRDS. 



of their increase, we may be content that Chickadees and 

 other birds eat them. 



Dr. Weed, who has studied the winter food of the Chick- 

 adee, says that the destruction of the myriad eggs of plant 

 lice, which infest fruit, shade, and forest trees, is probably 

 the most important service which the Chickadee ren- 

 ders during its winter residence. More than four 

 hundred and fifty eggs are sometimes eaten by one 

 bird in a single day. On the supposition that one 

 hundred were eaten daily by each of a flock of ten 

 Chickadees, there would be destroyed one thousand a day, 

 or one hundred thousand during the days of winter, by ten 

 birds onl}", — a number which he believes to be far below 

 the real condition, could we determine it precisely. Dr. 

 Weed has found in Chickadees' stomachs a carabid beetle, 

 a snout beetle, a leaf hopper, and remains of what appeared 

 to be the oyster-shell bark louse. This prying bird eats 

 many of the most injurious insects that might escape the 

 observation of larger birds. The cocoons of certain mici'o- 

 lepidoptera that hibernate on the twigs of fruit trees are 

 eagerly songht by these birds. The little case-bearers are 

 greedily eaten by them. 



Thus we see that the Chickadee feeds on borers which live 

 under the bark, on plant lice which suck the sap, on cater- 

 pillars which destroy the leaves, and on the cod- 

 ling moth which injures the fruit. It even digs 

 into decaying twigs, and extracts wood borers. 

 It has not the skill of the Woodpecker in going Fig. 5i.-Cort. 

 directly to the spot where the l)orer is located, imgmotb.par. 



•^ ^ entof theapple 



but it finds the burrow, and pecks and chips worm, eaten by 

 away the decayed wood along it until the larva 

 is reached. Undoubtedly Chickadees kill many of the de- 

 structive white pine weevils (Pissodes strobi). While work- 

 ing among pine trees I saw several Chickadees go to infested 

 shoots, peck them, and apparently extract the larva\ These 

 dying shoots seemed to he the principal attraction which 

 brought them to the pines. 



The practical value of the Chickadee to the orchard! st may 

 be inferred from the results of the experiment referred to on 





