) 
FOOD HABITS OF SHOAL-WATER DUCKS, 21 
adept at fly-catching. The larvae of midges (Chironomidae) were 
found in 61 stomachs, sometimes in very large numbers, and formed 
the bulk of the dipterousfood taken. They are abundant in shallow, 
standing water and slow streams almost everywhere, feeding upon 
decayed vegetable matter, and evidently are eagerly sought by the 
ducks. The larvae and pupae of craneflies (Tipulidae), soldierflies 
(Stratiomyidae), and Ephydridae were also commonly taken. 
Although beetles (Coleoptera) formed only 0.65 per cent of the 
total food, they were represented by a larger number of families and 
genera than the flies. ‘Those most commonly taken were predacious 
diving beetles (Dytiscidae), water scavenger beetles (Hydrophilidae), 
crawling water beetles (Haliplidae), snout beetles and other weevils 
(Rhynchophora), and ground beetles (Carabidae). 
Next in order of importance in the insect food of this teal come 
the bugs (Hemiptera), with 0.54: per cent, including both the true 
bugs (Heteroptera) and the cicadas, leafhoppers, etc. (Homop- 
tera). Of the true bugs, water boatmen (Corixidae) were found in 
32 stomachs, sometimes in very large numbers; back swimmers 
(Notonectidae) in 4 stomachs; water striders (Gerridae) in 4; and 
unidentified bugs in 6. The Homoptera were represented by a single 
jassid, or leafhopper. 
Caddisflies (Phryganoidea) furnished 0.31 per cent of the total food 
of the birds examined. ‘These were taken in the form of the larvae, 
or caddis worms, which abound in creeks and ponds, or anywhere 
in shallow water containing the vegetation upon which the fly lar- 
vae feed. ‘They live within silk cases or hollow cylinders made by 
themselves and covered with a variety of materials, such as grains 
of sand, bits of leaves or rushes, or pieces of mollusk shell. These 
cases are open at each end, and the larva pulls itself along by means of 
three pairs of legs which, with the head, can be protruded from one 
end. Caddis larvae or cases were found in 46 stomachs, never in 
very large numbers. 
The remaining insect food (1 per cent) was made up of damsel- 
flies (Zygoptera), dragonflies (Anisoptera), stoneflies (Plecoptera), 
bird lice (Mallophaga), grasshoppers (Orthoptera), ant-lions (Neurop- 
tera), moths and butterflies (Lepidoptera), ants, bees, and wasps . 
(Hymenoptera), and a number of miscellaneous unidentified insects 
and their eggs, pupae, and larvae. Probably the largest single item 
among these miscellaneous orders of insects was the nymphs of 
damselflies and dragonflies, identified from 23 stomachs. 
MOLLUSKS (MOLLUSCA), 3.59 PER CENT. 
Next to insects, mollusks furnished the largest item of animal 
food for this teal, 3.59 per cent of the total. They were usually 
found broken, although whole snails were sometimes present. Empty 
