WEENS. 59 



Other beetles, mostly leaf -beetles (Chrysomelidse) were eaten to 

 the extent of a little more than 8 percent. While nearly all of the 

 leaf-beetles are theoretically harmful none of those identified in the 

 food are especially destructive to crops. 



Hymenoptera, including both ants and wasps, aggregate a little 

 more than IT percent of the wren's diet. They are a fairly constant 

 constituent of the food and do not appear to vary much according to 

 season. The greater number was found in March, but as only two 

 stomachs were collected in this month the record is not conclusive. 

 Ants form about 7 percent of the food. The economic relations of 

 these insects have been discussed elsewhere. Wasps make up the rest 

 of the item, about 10 percent, and have no especial economic signifi- 

 cance. Caterpillars and a few moths and some cocoons constitute a 

 little less than V2 percent of the wren's food. Contrary to what 

 might be expected, not all these are taken in summer. The 1-t 

 stomachs obtained in February contained caterpillars to the amount 

 of over 13 percent of their contents. They were probably found 

 hibernating in crevices of bark. A few moths were eaten, but, as 

 usual, they were only a small item of the food. Small cocoons of 

 tineid moths were found in a number of stomachs. 



Grasshoppers amount to 4 percent of the wren's diet. Most of 

 them are eaten during the summer and fall, though some appeared in 

 stomachs taken in January. While these insects are a favorite food 

 for many birds they are probably rather large and too terrestrial in 

 habits to be eaten in great numbers by wrens. Other insects, mostly 

 flies and a few remains which could not be identified, make up about 

 G percent of the stomachs' contents. Flies (Diptera) are eaten very 

 irregularly and appear not to be relished. Spiders are taken to the 

 extent of somewhat more than 5 percent of the total food. As spiders 

 live about trees, bushes, fences, rocks, and outbuildings it is not sur- 

 prising that they are captured by wrens, but the rule seems to be that 

 while all insectivorous birds eat spiders to some extent no species eats 

 many. 



List of insects found in stomachs of Bewick wren : 



COLEOPTERA. 



Cercyon fulvipenne. Diabrotica soror. 



Tlippodamia convergens. Cryptocepliahis castaneus. 



Cocinella t. calif ornica. Gastroidea sp. 



Scymnus marginicollis. Bruchus seminulum. 



Aphodius rugifrons. Blapstinus dilatatus. 



Microrhopala montana. Notoxus alamedce. 



Diachus auratus. Ccutorhynchus nodipennis. 



Crepidodera helwines. Pelenomus cavifrons. 



Bpitrix parvula. Apion sp. 

 Bxema conspersa. 



