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THE LIFE-HISTORY AND HABITS OF THE 

 GREENHOUSE WHITE FLY^ [ALE Y BODES 

 VAPORARIORUM Westd.). 



By E. HARGREAVES, A.R.C.Sc, D.I.C. 



{Imperial College of Science and Technology, South Kensington.) 



(With 56 Text-figures.) 



This insect is commonly known as the "Greenhouse White Fly," 

 from its general occurrence on greenhouse plants. It is classified as 

 follows : 



Family, Aleyrodidae ("Mealy wings"). Wings white, not trans- 

 parent; antennae with seven segments; both sexes winged; tarsus 

 with two segments. 



Sub-order, Phytophthires. Antennae long and simple; tarsi with 

 one or two segments. 



Homoptera. Fore wings not thickened at the base ; head bent over 

 to touch the coxae. 



Order, Rhynchota (Hemiptera). The mouth parts form a jointed 

 beak (rostrum), bent under the thorax; two pairs of wings. 



Aleyrodes vaporariorum, has a wide range of food plants, and prefers 

 potatoes, and such greenhouse plants as tomato, cucumber, melon, 

 heliotrope, lantana, salvia. Although the flies and larvae are very 

 small, they occur in such immense numbers that the plants become 

 impoverished, and the quantity and quality of such fruit as tomatoes 

 and cucumbers decreased. The whole of the under-side of the leaves 

 is often completely covered with the scale-like larvae and pupae. They 

 produce a large amount of excreta (honeydew), which falls on to the 



1 A paper on insecticidal treatment for White Fly has been delayed, pending the 

 result of further work : Mr Hargreaves' departure for the United States prevented the 

 second part of this paper, dealing with the treatment of White Fly, being completed. 

 It will appear in an early number. 



