306 THE ROSE APHIS. 



tip of the antennae, and horns black. The tail is 

 pointed, and without a style. 



Towards the beginning of February, if the wea- 

 ther be sufficiently warm to make the buds of the 

 rose-tree swell and appear green, these species of 

 Aphis will be found on them in considerable abun- 

 dance. They are now produced from small black 

 oval eggs, which were deposited in autumn on the 

 last year's shoots. If after their appearance the 

 weather become cold, almost the whole of them 

 suffer, and the trees are, for that year, in a great 

 measure, freed from them. 



Those that withstand the severity of the weather 

 seldom arrive at their full growth before April, 

 when, alter twice casting their skins, they usually 

 begin to breed. It then appears that they are all 

 females, and each of them produces a very numerous 

 progeny, and that without any intercourse with a 

 male insect. — These, though themselves produced 

 from eggs, are viviparous. Their young, when 

 they first come from the parent insects, are each 

 enveloped in a thin membrane that has the appear- 

 ance of an oval egg. This apparent egg adheres 

 by one extremity to the mother, while the young 

 Aphis proceeding from it extends the other, 

 by this means gradually drawing the ruptured 

 membrane over the head and body to the hind feet. 

 During the operation, and for some time afterwards, 

 the forepart of the head adheres, by the viscous mat- 

 ter about it, to the tail of the parent. Thus sus- 

 pended, it soon entirely frees itself from its former 

 envelopment i and when its limbs become a little 



