59 



a noxious species seems often to depend upon some interference with the usual natural 

 checks in the shape of parasites, or to the prevalence of suitable weather to the develop- 

 ment and increase of the broods. When we cultivate cereals or any plant of economic 

 value we, in effect, afford an abundance of good and appropriate food for the insects which 

 habitually live upon it. It will be recollected that the maple and other shade trees in 

 Brooklyn and New York used to be completely defoliated by the middle of summer by 

 the common Brown Drop or Measuring Worm, Eudalimia subsignaria. The European 

 sparrow rid the cities of this nuisance completely ; it cleaned them all out. Becent 

 examinations of the stomachs of this bird in Europe prove that, although it eats also 

 grain or farinaceous food, over fifty per cent, of its food is animal, chiefly the larvse of 

 insects. But other writers make, from experiment, the percentage less, and I do not feel 

 certain that the introduction of the sparrow is defensible on the ground that it is a strictly 

 useful bird on all occasions. But few things, animals or man himself, are always a prac- 

 tical success and on all occasions. Except as against this Brown Measuring Worm New 

 York could have got along without the help of the sparrows. 



Fig. 30. 



A common pest in the east is the hairy larva (Fig. 30) of the Yapourer Moth, Orgyia 

 leucostigma (Fig. 31), which, owing, perhaps, to its long hair-pencils used in making its 

 cocoon, is less readily eaten by sparrows or other birds. 



The true remedy for the Yapourer is the sweeping down of the egg masses laid out- 

 side of the cocoon by the wingless female. (Fig. 32 represents a, the wingless female 

 and the mass of eggs laid on the outside of the cocoon ; b, a young larva suspended by 

 its silken thread; c. the female chrysalis, and d that of the male.) With industry 

 and care there need never be any trouble from this insect, and a small sum of 

 money would rid all cities in a short time of this pest, were the cleaning of the city 



undertaken at the proper moment. Other species occasionally increase largely in certain 

 seasons from unknown causes. On Mount Desert one season I saw myriads of 

 the Pretty Pine Spanner, Cleora pulchraria, which is not usually so plentiful. The 

 several species of pine, native and imported, become infested by the Pine Pest, Pinipestis 

 zirrvtnermani, a small pyralid, the larva of which seems to have but one annual 

 brood, feeding beneath the bark, causing the gum to exude and deforming the tree 

 by swellings. This insect is widely spread over the Middle States. Now it is evi- 

 dent that we can only diminish effectively the numbers and the damage caused by 



