40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



insects more or less to the l)ark surface upon which many of them 

 dwell. These insects mostly below the size of food objects ordinarily 

 taken by birds were identified 17 times in the stomachs of nine species 

 of birds. In one case, that of a chimney swift the stomach contained 

 hundreds of specimens, gleaned no doubt from a swarm on the wing. 

 Percentage of identifications among those of all insects, .0089; per- 

 centage of species in this group among the whole number of insect 

 species, .0780. 



MALLOPHAGA (BITING LICE) 



The only opportunity birds have to get these usually minute insects 

 is to capture those parasitic on their own bodies, or in the case of 

 raptorial birds to engulf some with their prey. Apparently either of 

 these occurrences is rare ; six records for as many species of birds 

 being all included in the present tabulation. Percentage of identifica- 

 tions among those of all insects, .0031 ; percentage of species in this 

 group among all insect species, .3383. 



SIPIIONAPTERA (fLEAS) 



Only a single instance of a flea being eaten by a bird has thus far 

 come to light ; the opportunities for getting these small agile insects 

 must be very few since our native birds are parasitized by fleas to only 

 a very slight extent. That fleas are in no way distasteful (as food) 

 to some of their hosts is evident to anyone who has observed dogs, 

 monkeys, and other animals in their persistent and often successful 

 search for these pests. 



Percentage of identifications among those of all insects, .0005 ; per- 

 centage of species in this group among all insect species, .0130. 



thysanoptf.ra (thrips) 



Protective adaptations. — Some are contrastingly black and white 

 colored and the immature stages of many are red. It is doubtful 

 however if these colors have any warning significance. The small size 

 and secretive habits of these insects doubtless are the most eft'ective 

 factors in restricting predation upon them. 



Bird enemies. — No identifications of thrips appear in the analyses 

 of the stomach contents of nearctic birds here reported upon. 

 VVetmore reports a thrips from the stomach of a hummingbird 

 (Anthracothorax viridis) from Porto Rico. (Bull. 326. U. S. Dep. 

 Agr., p. 73, 1916.) 



Other enemies. — Thrips are eaten by small predacious hemiptera, 

 especially Anthocoridae, and egg parasites are known. Hamilton 



