NO. 7 



PROTECTIVK ADAPTATIONS M cATKK 



Identifications of Hymciwptcra — Continued 



91 



Number of 



Family identifications 



Panurgidae 2 



Nomadidae 12 



Euceridae 10 



Anthophoridae 4 



Hylaeidae i 



Colletidae 8 



Megachilidae 18 



Ceratinidae 2 



Stelidae i 



Xylocopidae 2 



Apidae 130 



Apoidea (further unidenti- 

 fied) 372 



Unidentified 10,682 



Examination of the preceding tabulation shows again the influence 

 of availability upon choice of food. It is at once evident that the 

 groups more numerous in species and individuals are taken most often 

 by birds. Whether all are taken in sufficient number to satisfy expec- 

 tations is subject to discussion but the relativity of capture to abun- 

 dance is unmistakable. Superfamilies such as the Cynipoidea and 

 Chalcidoidea, owing to the minute size of most of their species, could 

 not be expected to figure largely in the diet of birds, and the same is 

 true for most Serphoidea. These are just the groups and the only 

 ones in the table except the Sphecoidea that seem obviously to be 

 inadequately represented. The Sphecoidea perhaps verge toward the 

 opposite limit of size for bird food. 



Since so many Hymenoptera were determined no further than to 

 the order, the number of species (over 300) of birds eating these 

 unidentified forms may be taken as an approximation to the entire 

 number of bird species consuming Hymenoptera. It is enough at any 

 rate to indicate that Hymenoptera are eaten by birds of all groups 

 studied, just as the total number of records (over 27,000) of Hymen- 

 optera clearly shows that these insects are one of the most important 

 elements of bird food. 



Beginning our consideration of the Hymenoptera with the sawflies, 

 it may be said that some of these insects are alleged to obtain pro- 

 tection from their resemblance to stinging members of the order. As 



