^2 NEW VOUK STATE MLSELM 



Tl-<0<iUOnYTIOAK 



Jl'rn/s 



Tlu- house wren is the only species tliat has been seen by our observers 

 to cat hairv caterpillars. It can hardly be called a common birtl, and it has 

 only occasionally been seen to eat these caterpillars. 



PARIDAE 



Xitlhalclics and tiliiiicc 



The chickadee, the common representative of the titmouse family, and 

 one of the most useful of all i)irds, is a <rreat destroyer of hairy caterpillars. 

 .\'ot only does it eat caterpillars of ;dl sizes, feedin^r them to its young, but 

 it destroys all forms of tiiese insects, except, perhaps, the eggs of some 

 species. Too much can not ije said in favor of this most useful and harmless 

 bird. Both species of nuthatch take these larvae only as they come in their 

 way on the trunks of trees, and not always even then. 



XURRIOAK 



Tliriixlifs 



While the thrushes eat hairy catc-rpillars wlicn they come in their wa\\ 

 they do not, with the e.xception of the robin, a|)pear to search them out. 

 The robin seems to be in this way the most useful of all thrushes. The 

 wood thrush and Wilson's thrush occasionally visit localities infested by the 

 caterpillars and cat a few, but the robin visits them frequent!)' and eats 

 many. The thrushes eat mainly the larger caterpillars. 



The bluebird is useful in destroj'ing most forms of these insects, Iiut as 

 bluebirds are not plentiful in the infested region the opportunity for obser- 

 vation has not been so good as in the case of some other species. 



Prof. .S. A. Forbes, state entomologist of Illinois, has made an extended 

 study of the food habits of different birds and he estimates that there are 

 about 10,000 insects per acre; over the entire stale, and on this basis con- 

 cludes that if the operations of birds were suspended entirely for a period 

 of seven years, the entire state would !>(■ carpeted with insects, one to the 

 s(|uare inch. Professor Forbes gives this as an illustration, liy no means as 

 a prediction, and it certainly is a graphic wav of stating the high value he 

 places on bird life as a means of checking the depredations of insect pests. 

 Professor I-'orbes has estimated that should the ])eopIe of the state apply 

 appropriate measures to increase the efticiency of bird life in destroying 

 insects, even if it was no more than \'',, the agriculturists of that state would 

 be saved $76,000 a yc^ar at the lowest, and ])robaI)ly five times that amount. 



