THE ENEMIES OF INSECTS 245 



These sticky tongues, indeed, are possessed by numerous 

 insectivorous creatures widely separated in the scale of 

 animal life. The woodpeckers have them, so too have 

 the frogs and toads. Our common toad has a trick, ex- 

 asperating to bee-keepers, of stationing itself near the 

 alighting platform of a hive, and flicking up the busy 

 inmates as they fly past. It is one of the few animals 

 that are indifferent to the bee's sting. 



The most consistently insectivorous groups, however, 

 are the birds and the fresh-water fishes ; and from an 

 economic standpoint birds must be given the first place, 

 for they are the chief destroyers of agricultural pests in 

 all parts of the world. This subject has been carefully 

 studied, especially in the United States ; and it is probable 

 that about two-thirds of the food consumed by birds in 

 a given district consists of insects. Moreover, wherever 

 any kind of insect pest is in the ascendant, birds rally to 

 the spot in abnormal numbers in order to avail themselves 

 of the feast. This fact is well illustrated by the following 

 case which was investigated by Dr. S. A. Forbes. An 

 Illinois apple orchard was being ravaged by "canker-worm" 

 — i.e. a species of looper caterpillar allied to that of our 

 March moth (Anisopteryx cescularia). It was visited by 

 an extraordinary number and variety of birds, specimens 

 of which were shot in order that the contents of their 

 crops might be examined. " Birds of the most varied 

 character and habits, migrant and resident, of all sizes, 

 from the tiny wren to the blue-jay, birds of the forest, 

 garden and meadow, those of arboreal and those of terres- 

 trial habits, w r ere certainly either attracted or detained 

 here by the bountiful supply of insect food, and were 

 feeding freely upon the species most abundant. That 

 thirty-five per cent, of the food of all the birds congregated 

 in this orchard should have consisted of a single species 



