THE PEA GREEN MOTH. 147 



one of the peculiar labial palpi of the perfect 

 insect. 



Another species of this genus is extremely 

 common, and is popularly known by the name 

 of the Pea Green Moth {Tortrix viridana) on 

 account of its colour. The upper wings are of 

 a beautiful pea-green, the lower pair being pale 

 brown. 



The larva of this insect feeds on the oak, and 

 in some years swarms in countless myriads, 

 so that the verdure of the oak-trees is sensibly 

 diminished. At such times, if the branches of 

 the oak be smartly struck, or even if a heavy 

 blow be given to the trunk of the tree, a vast 

 quantity of insect life becomes suddenly dis- 

 covered. Should the Moths be out, a whole army 

 of them will come fluttering from the foliage, 

 looking exactly as if they had been scraps of 

 green leaves which had suddenly assumed life. 



At this time, while the larvae are still engaged 

 in the business of feeding, thousands of little 

 caterpillars come dropping down from the 

 branches, each hanging by a very slight but 

 very tough silken thread, which they can be 

 induced to lengthen almost to any extent, by 

 simply continuing the blows which first startled 

 them out of their leafy homes. 

 L 2 



