﻿18 BULLETIISr 1359, U. S. DEPAETMENT OF AGRICULTURE 



27 times, were most abundantly represented. Remains of many were 

 found in several of the stomachs opened, and small fragments were 

 often present in stomachs filled with other insects. Water stridors 

 (Gerris) were found three times, true water bugs of small size (Belo- 

 stoma) six times, and back-swimmers (Notonectidse) twice. A shore 

 bug {Salda) was identified once. Shore bugs are often abundant on 

 mud bars where stilts delight to feed, but apparently are usually 

 overlooked or disregarded. 



Coleoptera. — Beetles, practically as important in the food as the 

 bugs, composed 32.4 per cent, but were present in much greater 

 variety. A tiger beetle (Cicindela), founa in one instance, is the 

 only species taken that may be considered beneficial. Small flat 

 beetles of the genus Bembidion, of which a variety of species inhabit 

 muddy shores, were found twice and other ground beetles (Cara- 

 bidse) seven times. Crawhng water-beetles (Haliplidse) were identified 

 in 18 instances, among them representatives of various species. Pre- 

 dacious diving beetles were identified 26 times and their larvse 9 

 times. The species of this group taken by the stilt were those of 

 small size, as the bird is unable to swallow the larger forms. The 

 same fact was observed in the water-scavenger beetles identified in 

 58 stomachs. The genus Berosus, the species of which are frequently 

 abundant in shallow water, was found 21 times and the genus Tropi- 

 sternus, 28. Larvae of water-scavenger beetles were identified in 22 

 instances, so that on the whole this group of beetles was abundantly 

 represented. 



An abundance of weevils is noted as one of the prominent items 

 among the beetles. Curculionidse alone were represented in 44 stom- 

 achs and billbugs (SpJienophorus) in 6. The curculios eaten were 

 mainly individuals of the genera Bagous and Ony chilis, which occur 

 on aquatic vegetation. Weevils are mostly injurious, and attention 

 may be drawn to the evident predilection for these beetles shown 

 by the stilt. 



Diptera. — Flies amount to 9.7 per cent of the total food. The 

 majority were still in the immature stages, though occasionally adult 

 flies were eaten. These remains were most abundant in material from 

 the Great Basin region, where certain groups of dipterans abound. 

 The young of small crane flies (Limnobiinse) were found 3 times and 

 of gnats (Chironomidas) 4 times. The larval forms of mosquitoes 

 were identified twice, evidence of good that may be accomplished in 

 the destruction of these pests. Alkali flies (Ephydridse) , and soldier 

 flies (Stratiomyiidae) , represented by several forms, were encoun- 

 tered 9 times each. The species of flies taken, so far as it was 

 possible to identify them, are without exception those having larval 

 forms of aquatic habit. 



MoUusca. — Represented by several common species of marsh or 

 pond inhabiting snails, moUusks make up 7.9 per cent of the food, and 

 were identified 35 times in all, most abundantly in material collected 

 in Florida. In 37 birds taken in April (all but 2 from Florida) snails 

 amounted to 15.4 per cent of the food. 



Pisces. — Small fishes were identified in 7 instances, but amount 

 to only 3.2 per cent of the total food. A carp was found once and 

 tiny sunfishes twice, but remains of others were not identified. The 

 fishes eaten were of the smallest size and have little economic 

 significance. 



