INSECTS AFFECTING PARK AND WOODLAND TREES 27 



detailed information concerning- the voracity of certain birds feeding upon 

 gipsy moth caterpillars, a species of much importance not only to Massa- 

 chusetts but to the entire northeastern United States. 



CirSV MOTH tATKKrU.I.ARS KATKN UV lUKDS 



May 12 A yellow warbler ate 15 caterpillars in less than 5 minutes. 

 May 12 A Nashville warbler ate 42 caterpillars in y. hour, in the mean- 

 time taking many more. 

 May 18 A scarlet tanager ate upwards of 30 caterpillars within 5 minutes. 

 May 18 Two scarlet tanagers together ate small caterpillars at the rate of 



35 a minute for 18 minutes. 

 May 20 A crow blackbird ate 40 caterpillars in a little over 3 minutes. 

 May 26 A Maryland yellowthroat ate 52 caterpillars while moving in and 



out among trees. Time not taken. 

 May 26 A redstart ate 31 caterpillars while moving about. Time not taken. 

 A red-eyed vireo ate, in four brief visits to an infested tree, 37 

 caterpillars. 

 July 13 A yellow-billed cuckoo ate 1 every 2 minutes for 36 minutes. 



A red-eyed vireo ate 73 in 40 minutes, 

 luly 14 A yellow-billed cuckoo ate 81 in 48 minutes. 



July 15 A towhee ate 7 pupae and 2 caterpillars in a very short time. 

 Exact time not noted. 

 These facts indicate that birds must be exceedingly effective checks on 

 outbreaks of such leaf feeders. This record is by no means exceptional as 

 may be seen in the following paragraph by Mr E. H. Forbush :' 



As showing the large numbers of these caterpillars eaten by birds, a 

 few notes from^Mr Mosher's observations will be of interest. A black-billed 

 cuckoo was seen to eat 36 forest tent caterpillars within 5 minutes. Red- 

 eyed vireos (probably a pair) took 92 forest tent caterpillars from a tree 

 within an hour. They were also eating span worms and other larvae and 

 plant lice. A male Baltimore oriole went into a tree infested by these cat- 

 erpillars, where he stayed 4 minutes, killing 18 caterpillars in that time; 

 coming a little later he stayed 7 minutes, and took 26 caterpillars. A pair 

 of blue jays came to the tree 24 times during 3 hours, taking 2 or 3 cater- 

 pillars at each visit. 



Those not familiar with bird life will be surprised to know how many 

 species prey on injurious insects. Mr Forbush has recently published a 



■ iQoo Mass. Crop Rep't. July- P- 29. 



