INSECTS IN RELATION TO OTHER ANIMALS 299 



Coccinellidse are eaten by but very few birds the flycatchers 

 and swallows and are refused by caged blue-jays and song 

 sparrows even when these birds are hungry. Of Chrysomel- 

 idae, the Colorado potato beetle is refused by the catbird, blue- 

 jay and song sparrow, and Diabrotica is not often eaten, ex- 

 cept by catbirds and thrushes. " The smaller Carabidge, 

 whether stinking or not, are eaten by practically all land birds." 

 Crows, blackbirds and jays eagerly swallow Calosoma scruta- 

 tor, and the first two birds are especially fond of Harpalus 

 caliginosus and H. pennsylvanicus, and feed Galerita to their 

 young. " A score of smaller Carabidse and Chrysomelidse, 

 metallic and conspicuously colored, are habitually eaten by 

 birds that have an abundance of other insect food to pick 

 from." 



The stenches of Lampyridae appear to be more effective 

 than those of Carabidse. Telephorus is occasionally eaten, but 

 P ho tinus rarely if at all. Chauliognathus is not eaten by 

 many birds (though flycatchers and swallows select this in- 

 sect) and the genus is regarded unfavorably by caged catbirds 

 and blue-jays. 



In regard to other insects, Judd finds that Epicauta, with its 

 irritant fluid, is immune from all but the kingbird; Cyllene 

 seldom occurs in the stomachs of birds; May flies and caddis 

 flies, however, are terribly persecuted, but swiftly flying Dip- 

 tera and Odonata are highly immune. 



From such facts as these, Judd properly infers, " not cases 

 of protection and non-protection, but cases of greater and 

 lesser efficiency of protective devices." 



2. THE TRANSMISSION OF DISEASES BY INSECTS. 



It is now known that several kinds of insects are of vital 

 importance to man as agents in the transmission of certain 

 diseases. This recently demonstrated role of insects now 

 commands universal attention. 



Malaria. So far as is known, malaria is transmissible 

 only through the agency of mosquitoes. 



