FOOD HABITS OF THE SWALLOWS. 17 



beetles were identified, of which the majority are injurious to plant 

 life in some form. 



Ants (6.37 per cent), many of which are winged forms, seem to be 

 well relished by tree swallows. Most of them are eaten from May to 

 October. February is the month of maximum consumption (25 per 

 cent) ; but as only 4 stomachs were taken in this month, the record 

 can not be considered representative. The great bulk of this food 

 was taken from May to October. Hymenoptera other than ants 

 (7.58 per cent) were taken in every month but two, March and 

 December; and as but few stomachs were secured in these months, 

 the omission is probably accidental. This item of food is made up 

 of wild bees and wasps, with a large proportion of parasitic species. 

 No domestic bees were observed. 



Hemiptera, the order including widely different insects, from the 

 little plant louse (aphid) to the large harvest fly (cicada), do not 

 appear repugnant to birds because of their odor ; in fact, the family 

 Pentatomidse, generally known as stinkbugs, forms a staple article of 

 diet of most insectivorous birds. They were found in 5 stomachs 

 of the tree swallow. Tree hoppers (Membracidse) were found in 6 

 stomachs, leaf hoppers ( Jassidse) in 9, and plant lice (Aphididse) in 

 11. Probably more of the last were present, but these fragile creatures 

 are so easily reduced to a pulp that the action of the stomach soon 

 renders them unrecognizable. The most interesting family of the 

 Hemiptera in this connection are the Lygseidae, found in only 3 

 stomachs, but in one represented by the remains of 80 chinch bugs 

 (BUssus leucopterus) . The bird had evidently encountered a swarm 

 of these insects in flight and had filled up on them, an indication that 

 they are palatable and will be taken whenever found. 



Diptera form the largest item of the tree swallow's food (40.54 

 per cent) . They were eaten all through the year, but mostly in the 

 colder months. The greatest quantity (89.5 per cent) was taken in 

 November and the least (6.98 per cent) in August, which is prover- 

 bially the month of flies. While numerous, they represent but few 

 families, and only 5 were identified in the stomachs: Craneflies 

 (Tipulidse), horseflies (Tabanidse), robberflies (Asilidse), flower flies 

 (Syrphidse), and house flies (Muscidse), the last of which were by 

 far the most numerous. The syrphus flies, found in 10 stomachs, are 

 usually considered useful insects, as many when in the larval state 

 feed upon plant lice and others act as scavengers. 



Lepidoptera were eaten only in the months from April to Septem- 

 ber, the greatest quantity in August (5.02 per cent) . They were found 

 in 20 stomachs, 15 of which contained the adult moths and 5 the larvae, 

 or caterpillars; an indication that the bird takes the adult insect 

 probably because of its method of feeding — upon the wing. The 

 average for the year is only 1.07 per cent. 



