Larvae and their Work 



again; and each time the leaf becomes slightly more curled. 

 At length, after many hours' work, during which the larva 

 has scarcely ever cried a halt, the leaf is rolled and the 

 caterpillar seeks a well-deserved rest within its newly 

 built home. So common are these rolled leaves, we pass 

 them by unnoticed every summer in their hundreds of 

 thousands, yet each leaf represents the result of the 

 untiring labours of a clever and industrious little insect. 



Equally common in our hedgerows is the home of the 

 " cuckoo spit " insect, or " frog-hopper." The larva frog- 

 hopper, unable to escape its enemies by a series of gigantic 

 leaps, like its parents, must needs have some protection. 

 He cannot build a leaf shelter, he cannot roll leaves nor 

 burrow into the ground, but he has a big appetite and he 

 puts it to good use, or would do so if certain clever birds 

 had not found him out. Related to the green-flies, he, like 

 them, possesses an awl-like mouth, which he digs into 

 plant stems and sucks sap therefrom in quantity. Much 

 of this sap he ejects in the form of a somewhat sticky, 

 clear liquid ; having done so, he wags his tail so violently 

 that the liquid is beaten up into a froth which completely 

 covers him ; it is, in fact, the well-known cuckoo spit. If 

 left alone the larva would develop into a full-grown frog- 

 hopper within his hiding-place, but certain birds have seen 

 through his subterfuge and rudely pluck him from his 

 shelter, to his discomfort. The leaf-rollers have their 

 counterpart in the leaf-miners, which may be the larvae 

 either of moths, beetles, or flies, the first-named being the 

 commonest. 



The least observant among us must have seen some 

 mined leaves. Roses, celery, thistles and oak are amongst 

 the plants whose leaves are most frequently mined. It 

 will be easier to understand how these little insects 

 work if we know something of the general structure of a 

 leaf. In very non-technical language, each leaf may be 

 looked upon as a kind of sandwich, with soft green 

 vegetable matter between an upper and lower parchment- 



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