70 APHIS VASTATOR. 



the vastator, and I do not think it thrives quite so well upon 

 it as upon plants which I shall hereafter describe. 



(278.) So restless an insect is it, that when 1 have 

 placed it upon one plant in my sitting-room, where other 

 plants were also present, I generally found that part of the 

 creatures had crawled to the other plants ; in fact, I have 

 observed that my specimens have wandered all over my 

 library. 



(279.) When these little creatures crawl over the skin, 

 they produce a tickling, too exaggerated to be pleasant ; 

 in fact, their crawling is attended with a sensation which 

 is quite painful. These little fellows look very majestic, 

 marching with their antennae extended before them. 



(280.) When the creature first appears, he is to be found 

 sparingly distributed over the larger leaves of the plant ; 

 but when the greater part of the plant is destroyed, and the 

 insect has multiplied, great numbers may be found on a 

 single leaf, as though they were determined utterly to 

 annihilate it. The leaflet figured contained about eighty 

 insects upon it. 



(281.) They then become partially starved, enter into 

 the pupa state, cast their skins, and emerge as winged 

 insects, when they fly away, and leave no trace behind 

 them save and except the destruction of the plant, and 

 some few specimens which have been injured by the 

 ichneumons. This fact is exceedingly remarkable, for on 

 watching a piece of land, I have found scarcely one of the 

 insects to be left behind, after the greater part had had 

 their wings developed and had flown away. I think that 

 from the period of birth it requires about a fortnight before 

 the Aphis obtains wings and flies away. 



(282.) The Aphides over a whole field take wing about 



