48 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE. 



FLIES (DIPTERA); AND ANTS, BEES, AND WASPS (HYMENOPTERA), 0.07 PER CENT. 



Most of the flies eaten by wood ducks were in the larval form. 

 Larvae of soldierflies (Stratiomyidae) predominated, having been 

 taken by 33 of the ducks, while the gnats and midges (Chironomidae)., 

 craneflies (Tipulidae), flowerflies (Syrphidae), and the Scatophagidae 

 were sparingly represented. Ants were commonly eaten, but always 

 singly or in small numbers, never constituting a very large percentage 

 of the total food. Seven genera were identified, Crematogaster and 

 Campoiwtus predominating. Wasps (Vespoidea), parasitic wasps 

 (Ichneumonoidea) , sawflies (Tenthredinoidea), bees (Apoidea), chal- 

 cids (Chalcidoidea), and serphoids (Serphoidea) also were occasionally 

 taken. 



MISCELLANEOUS INSECTS, 0.97 PER CENT. 



Prominent among the miscellaneous insect food of the wood ducks 

 were the caterpillars and chrysalides of moths and butterflies (Lepi- 

 doptera), and the larvae and larval cases of caddisflies (Phryganoidea). 

 One stomach examined contained no fewer than 85 noctuid moths, 

 many of them with eggs. This family includes the cutworm moths, 

 and practically all of its members are injurious to cultivated crops. 

 A few Mayfly nymphs (Agnatha), termites (Isoptera), unidentified 

 larvae, pupae, and galls, etc., were included among the miscellaneous 

 insects. 



SPIDERS AND MITES (ARACHNIDA), 0.63 PER CENT. 



The wood duck's taste for spiders is quite marked. Several full 

 stomachs from southern localities contained remains of from 20 to 40 

 spiders, these in some cases constituting as much as 75 or 80 per cent 

 of the contents. Leathery or silken cases containing spider eggs 

 occasionally are taken, and tiny water mites (Hydrachnidae) were 

 found in 5 stomachs. 



MISCELLANEOUS ANIMAL FOOD, 2.79 PER CENT. 



Contrary to the habit of most other ducks, the wood duck pays 

 little attention to mollusks, probably because they are not plentiful 

 in its usual haunts. A very few snails and small bivalves were found 

 in the stomachs examined. Crustaceans (0.08 per cent) were also 

 scarce, being represented by a few beach fleas (Amphipoda), sowbugs 

 (Oniscidae), water asels (Asellidae), and occasional claws of crawfish 

 (Astacidae). Remains of small fishes, found in 5 stomachs; bones 

 of frogs, in 2; 2 centipedes, and a few of the reproductive buds, or 

 statoblasts, of fresh-water bryozoa, complete the list of food items. 



