546 INSECTS AT HOME. 



their skin, the ants instantly carry it away, nc r will they let 

 any dirt or rubbish remain among them or on them. 



' But the most amusing- care of the ant is guarding the 

 Ajahides from the attacks of that little parasitic fly, whose 

 operations Mr. Haliday has so well described. You must have 

 seen a sheep-dog run over the backs of a whole flock of sheep, 

 when closely crowded together, in order to bring back some 

 sinner that has gone astray ; so will the ants, in the hot 

 sunshine, run about over an establishment of Aphides, driving 

 away the rascally parasite that is for ever hovering over to 

 destroy them.' 



The reader will doubtless have noticed that some Aphides 

 have wings and that others have none. In fact, by far the 

 greater number of these insects are without wings, like the 

 central figure on Woodcut LXII. In the early part of the 

 year they are all without wings, those organs being added 

 about the end of summer. 



The effect which these insects have upon vegetation is 

 extraordinary. As to the hop-plant, it is in a great measure 

 dependent for its success upon the presence or absence of the 

 Aphis, which in hop-growing districts is called The Fly, no 

 other winged insect being deserving of such a name. All 

 hop-growers watch their crops with the utmost assiduity, and 

 the presence of the Aphis, though only upon a few plants, 

 causes consternation in the hearts of the growers. Owing to 

 the astonishing fecundity of the insect, and the rapid manner 

 in which plants which were perfectly free from the Aphis become 

 absolutely covered with its green armies, an idea is prevalent 

 that the insects are brought by certain winds ; and no sooner 

 does a chill, depressing, north or north-western wind blow for 

 any length of time, than all the gardeners' heads are shak- 

 ing ominously, and all their tongues are muttering fears of 

 blight. 



Now, absurd as are many of their notions, such an idea as 

 this could not have gained so universal a liold without having 

 some element of truth in it, which element I take to be this. 

 The Aphides form the food of very many insects. The larvae 

 of'the Ladybirds feed entirely upon them, and so do those of 

 the Lacewing-flies, both of which insects have already been 

 d'^iscril)(.'CJ. They are also eaten by the larvae of the swift and 



