312 



Habits of the Greenliouse White Fly 



0-39 mm, A very noticeable feature is the great increase in size (length 

 and breadth), which has taken place at the moult. (This also applies 

 to the two succeeding stages.) The rostrum is more pronounced than 

 in the previous stage (Fig. 16), but the general arrangement of the mouth- 

 parts is the same. This larva generally retains the same position as 

 the last, but I have observed one to move slightly immediately after 



I> 



Fig. 19. Leg of 

 second instar. 



Second instar. 



emergence. The margin is at first entire except for the cerci and the 

 pair of more anterior spines, both being shorter than in the previous 

 stage. Later, however, a waxy fringe is developed. When this is 

 dissolved, the body margin is seen to have become creiiulated (Fig 17). 

 There is a metathoracic and six abdominal segments differentiated. 



Tracheal system (Fig. 18). There are dorsal and ventral systems 

 which are connected, and very few small branches are present. There 



