19 



feed upon them. When the moths emerge in number, however, they 

 are preyed upon b}^ a great many birds, and even the English spar- 

 row destroj^s large numbers of them. Jul}- 16, 1897, Mr. Kirkland 

 observed whole flocks of English sparrows following along the lines 

 of fences carefully searching for the moths, which when found were 

 greedily devoured. Of course many of these moths will have laid 

 their eggs before they are destroyed, yet the work as a whole counts. 

 Bats and toads also eat the moths as they fl}'^ about electric lights, 

 the latter devouring them when the}^ fall to the ground. 



Certain of our native parasites which destroy allied insects like the 

 fall webworm and the tussock moth also breed in the brown-tail moth, 

 but the percentage of parasitism is very small. 



An effort is being made to introduce the European parasites of both 

 the brown-tail moth and the gipsy moth, and during the past year 

 many thousands of such parasites have been introduced and liberated 

 in the vicinity of Boston. They are first cared for in a laboratorj^ at 

 North Saugus; many of them are afterwards studied under outdoor 

 tents, while still others have been liberated in the open in badl}^ 

 infested woodlands. The results down to the present time are encour- 

 aging, but it may be a matter of some years before appreciable results 

 are obtained, and there is a possibility, also, that these P^uropean para- 

 sites will not multiply to the same extent as in Europe. Therefore 

 active mechanical measuj-es must still be continued, and perhaps for 

 years to come, in the actual destruction of the injurious insect. 



REMEDIES. 



The most obvious means of controlling the brown-tail moth, and the 

 easiest one, is the collection and destruction of the winter nests after 

 the leaves have fallen. These webs, elsewhere described, are con- 

 spicuous from October to April. Many of them are within reach, and 

 as each contains 200 caterpillars or more, each one capable of destroy- 

 ing a number of buds in the spring, the value of this work is at once 

 evident. The webs should be removed before the first part of April. 

 In Massachusetts, on the larger trees, are used long ladders and climb- 

 ing irons, and some men make a business of destroying these nests 

 upon private estates. The twigs carrying the nests are clipped off 

 with one of the ordinar}^ tree pruners (fig. 10) and the collected nests 

 are burned. 



After the leaves come out in the spring the nests remaining on the 

 trees will be empty, and it is no longer worth while to make an effort 

 to collect them. Practically the only remedy after this date is spray- 

 ing with an arsenical mixture. When they are young the larvae may 

 be effectively destroyed by spraying with arsenate of lead. They may 



364 



