64 APHIS VASTATOR. 



(251.) If the insect be touched, it will be found that it 

 adheres pretty firmly to the leaf by its suctorial apparatus, 

 and that it requires one or two seconds to disengage itself 

 from its position. 



(252.) The color of this little insect is various: in very 

 early life its body is nearly transparent ; later it is of an 

 olive color ; at other times it is grass green, and at a later 

 period it may be found to be of a reddish color. 



(253.) We have in this little insect a parasite which 

 derives its nourishment from the plant by sucking the 

 juices, which operation it effects by means of the very 

 curious apparatus which I shall hereafter describe. 



(254.) This insect is found in three stages of exist- 

 ence, the larva, the pupa, and the imago, or perfect 

 winged insect ; in all of which states, like its congeners, it 

 feeds, remains active, and probably multiplies. 



(255.) From an examination of its different states, we 

 know that it not only belongs to the family of Aphida, but 

 must be classed under the genus Aphis. 



(256.) The Aphis vastator when full grown is about the 

 tenth of an inch long, and, as I have before mentioned, the 

 color is white, olive green, brown, or inclined to red. 



(257.) The Antennae are seven-jointed ; they are nearly 

 as long as the body, and sometimes even longer. The 

 subjoined measurement of a specimen, which I take to be 

 an adult apterous female, shows the dimensions of the 

 various parts of the insect in lOOOths of an inch: 



Length of body from base of antennae to apex of abdomen 106 



Greatest breadth of body - - --, 55 



Breadth of head between the eyes - - 12 



Antei-ior femur - ' ; S- -. - 22 



" tibia - ** * ~ - - 36 



