INSECT FOOD. 89 



The particular species eaten was in each case Tlippodamia maculata. 

 It was not noticeably abundant at the time it Avas taken, but during 

 August, 1896, it was the most conspicuous insect on the farm. Then, 

 however, it was not molested. Ladybirds of another species {Cocci- 

 nella 9-notata) weTeyevy numerous when the pea plant-louse was mak- 

 ing havoc, and appeared on ever}' pea vine greedih^ devouring the 

 plant-lice. It was, fortunately, quite free from attack by birds. 

 Indeed, ladybirds appear to be distasteful to birds. I have offered 

 them to a dozen different caged birds, and they have always been 

 refused. 



Flies. — Beneficial diptera, such as the predatory robber-flies and the 

 parasitic tachinid and syrphid flies, are too alert to be caught b}^ any 

 birds except flycatchers and swallows, and even these secure them 

 rarely. During June and July, when robber-flies were plentiful, 

 birds were not found disturbing them. Syrphid flies were so numer- 

 ous during the last of August, 1899, that several would alight on nn^ 

 camera whenever it was set down, but a score of birds collected then 

 had not made use of them as food. 



Bees" and wasps. — The most abundant and conspicuous of the useful 

 insects are bees and the flower-fertilizing species of wasps. Of the 

 615 native birds collected only 31, representing 20 species, had eaten 

 bees. It is interesting to note that the offenders were largely either 

 warblers or aerial feeders. The list is appended: 



List of birds examined vhose stomachs contained bees and vxisps. 



Chimney swift. Song sparrow. Yellow warbler. 



Ruby-throated humming- Scarlet tanager. Black-poll warbler. 



bird. Purple martin. Water-thrush. 



Kingbird. White-bellied swallow. Maryland yellow-throat. 



Rusty blackbird. Bank swallow. Canadian warbler. 



Henslow sparrow. Rough-winged swallow. Catbird. 



Chipping sparrow. Red-eyed vireo. Carolina chickadee. 



Practicall}^ all the bees eaten were small species of the family 

 Andrenid^, mainh^ Andrena and Hal let us; the larger species are 

 seldom taken. During May, 1900. bumblebees and carpenter bees con- 

 gregated in such numbers around locust trees white with grape-like 

 clusters that from sunrise to sunset a deep, continued hum arose as 

 from a hive: and when fruit trees were in blossom bees swarmed about 

 them also: but in both cases observation failed to discover an}^ con- 

 sumption of the insects b}^ birds. Blossoming persimmon trees alive 

 with bees were watched for several hours, but only one bird, a hum- 

 mingbird, visited them. 



No arculate wasps, except certain species of the family Scoliida?, 

 become food for birds: indeed, less than half a dozen of all the birds 



^Exclusive of the honey bee, which is considered separately (seep. 36). 



