The White Flies or Aleyrodids 



out and the skin is gradually worked backwards. At the end of 

 June the adults begin to issue again in numbers, remaining alive 

 for about twenty days. There are three generations annually. 

 When the perfect insect issues from what may be termed the 

 pupa shell, the wings are rolled up and make their appearance 

 with extreme slowness. Just before the adult is ready to issue 

 the pupa shell becomes transparent so that the contained insect, 

 shrunken away from the skin, is plainly seen in all of its stages. 

 The adult just after issuing is at first milk-white except for bright 

 lemon-yellow thoracic lobes. The adult male is readily dis- 

 tinguished from the female by the anal daspers and by the waxy 

 tufts issuing from the head and from the abdomen. All stages 

 are well represented in the accompanying figures. 



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