E. Hargreaves 3*2 1 



straighten out and harden. The k^gs are then successively drawn 

 out and straightened, and simultaneously with this the rest of the 

 thorax, bearing the wings which are curled up on each side. When 

 the legs have hardened, the insect uses them to push at the pupa case 

 for the extraction of the abdomen. It takes an hour or so for the wings 

 to become straight. The newly emerged imago is quite devoid of any 

 waxy covering, but after some time, its body and wings become covered 



Fij,'. 40. Adult's abdomen, lateral. Fig. 41. Adult's abdomen, ventral. 



with the white substance (meal, or wax), from which the names " white- 

 fly" and "mealy wing" are derived. It varies in length from 0-95 mm. 

 to 1-4 mm. I placed a newly emerged female insect on a slide beneath 

 a coverslip in order, if possible, to observe where the wax was formed. 

 After some time, I found that two pairs of plates were covered with it. 

 These are situated ventro-laterally on the second and third abdominal 



Fig. 42. Part of hind tibia. 



segments (Figs. 40, 41). The rest of the body was quite clean. On 

 careful observation of one of the flies while on a leaf, by means of a 

 binocular, I saw that it scraped its abdomen with the tibiae of its hind 

 legs, and then stroked them on its wings, and the remainder of the 

 abdomen. Similarly, it uses its fore-legs for the head and thorax. 

 On the hind tibia is a row of stiff setae, which act as a comb for the 

 transference of the wax (Fig. 42). There are four pairs of wax plates 



