TRAILL *S AND ALDER FLYCATCHERS. 61 



near the ground in bushes beside the water — in willows in the central 

 and western portions of the country and in alders in the east. No 

 special differences in the food habits have been noticed, and as many 

 of the stomachs used in this investigation were collected before the 

 two forms had been clearly distinguished, it is not practicable to 

 separate them now. 



In determining the food of this species there were available 135 

 stomachs collected in 17 States, the District of Columbia, New Bruns- 

 wick, Nova Scotia, and Ontario. California represents the farthest 

 point west and Texas the farthest south, but the Texas bird was 

 probably migrating. The stomachs are well distributed through the 

 months from May to September. One was taken in October, but as 

 its contents were somewhat exceptional it was not included in the 

 investigation. 



In the first analysis the food was found to consist of 96.05 per cent 

 of animal matter to 3.95 of vegetable. Nearly the whole of the vege- 

 table food was taken in August and September, and more than three- 

 fourths of it in the latter month, just previous to and during migra- 

 tion. 



Animal food. — Beetles of all kinds amount to 17.89 per cent. Of 

 these a few were the useful ladybird beetles that eat plant lice and 

 scales, but an overwhelming majority were harmful species, among 

 which were three specimens of the notorious cotton-boll weevil 

 (Antlionomus grandis) from a stomach taken in Texas, also the western 

 spotted cucumber beetle (Didbrotica soror), locust leaf miner (Odontota 

 dorsalis), and Lema trilineata. The last was the beetle that fed upon 

 and injured the potato before the introduction of the potato beetle 

 from Colorado. Besides these are a number of harmful weevils, 

 including 1 scolytid or engraver. Beetles were found in 108 stom- 

 achs, and 1 was entirely filled with them. They constitute a good 

 percentage of the food in every month, with the least in September, 

 when vegetable food is at a maximum. 



Hymenoptera are the largest item of animal food, not only in the 

 aggregate but in every month. They are mostly in the form of wasps 

 and bees, but there are a few of the parasitic species and some ants. 

 They amount to 41.37 per cent of the food, a record which is exceeded 

 by but 2 other flycatchers. Hymenoptera of all kinds were found in 

 93 stomachs and were the sole contents of 1 . 



Diptera, such as crane flies, robber flies, house flies, and dung flies, 

 were found in 47 stomachs and were the entire contents of 4. They 

 amount to 14.20 per cent of the food and are eaten very regularly in 

 every month except September, when they fall to 8.05 per cent. 



Hemiptera, mostly stinkbugs, but with representatives of several 

 other families, were contained in 44 stomachs, and amount to 7.24 per 

 cent of the food. The most interesting point connected with this item 



