THE GIPSY AND BROWN TAIL MOTHS I9 



observed feeding on these insects, and quotes Mr Kirkland to the 

 effect that the birds eat not only the moths, but their young. 

 Messrs Fernald and Kirkland state that the notorious English 

 sparrow has a strong redeeming trait in its fondness for the moths, 

 it ranking as their most formidable bird enemy. In addition to 

 the above mentioned birds, Mr E. H. Forbush has recorded the 

 robin, blue jay, black and white warbler, the rose-breasted gros- 

 beak, the chestnut-sided warbler, the scarlet tanager, redstart, 

 chickadees, red-eyed vireos and yellow-throated vireos and the 

 male indigo bird as feeding on the caterpillars. The blue jay and 

 the yellow-throated vireo are specially valuable. The records given 

 by Mr Forbush include the number of larvae eaten by each bird 

 and the time occupied. None ate less than nine, and one as many 

 as 57 caterpillars, the latter operation occupying 20 minutes. 

 These observations show that our native birds will undoubtedly 

 prove very efficient aids in checking this pest. Professor Fernald 

 has also recorded bats as feeding on the moths at night, and he 

 states that toads devour the caterpillars during the early summer 

 and the moths later in the season. 



Remedial measures. The conspicuous hibernating nests [pi. 2, 

 fig. 7] of this species are easily detected at any time when the 

 foliage is off the trees, and one of the most effective, methods of 

 checking this pest is to cut them off and burn them. This can be 

 very easily done with the aid of long handled pruning shears and 

 ladders. The insect is also readily controlled with arsenical poisons ; 

 and Professor Fernald reports experiments in spraying with arsenate 

 of lead, in which i pound to 150 gallons killed 50% of the cater- 

 pillars in four days, 90% in seven days and all in 13 days. Treat- 

 ment with the same insecticide, 2 pounds to 150 gallons, gave 

 similar results, and when 5 pounds were used to 150 gallons 80% 

 were dead within four days and all in nine days. The use of 10 

 pounds to 150 gallons resulted in the destruction of all the cater- 

 pillars in six days. 



Spraying with paris green, i pound to 150 gallons, killed 4% 

 in four days, 70% in six days and 90% in nine days, all being dead 

 in 12 days. 



The methods described above, while applicable to the more 

 valued fruit and shade trees, can hardly be employed to advantage 

 in forest "areas. This species it is feared may become a serious 

 pest in oak and maple timber unless natural enemies, either native 

 or introduced, prevent its becoming unduly abundant. It is 

 difficult at the present time to see how, with our present methods, 

 it can be fought successfully in extensive forest areas. 



