THE WHITE FLIES, OR ALEYRODIDS 



(Family Aleyrodidce.) 



This family, more closely allied to the Aphididae and 

 Coccidae than to any others, and yet widely different in important 

 features, is a puzzling and abnormal assemblage of insects. They 



Fig. 140. — Aleyrodes citri. (From hisect Life.) 



are very small insects, frequently minute, and infest the leaves of 

 plants, usually on the low^er side. In their early stages they are 

 scale-like, and much resemble some of the Coccidae. Unlike the 

 Coccidae, however, the development of the two sexes is prac- 

 tically parallel, and both males and females are active and winged. 

 Differing again from the scale insects, there are two pairs of 

 wings instead of one pair. All four wings are covered or dusted 

 with a whitish, meal-like secretion, which has given to the group 

 the popular name of white flies. In the immature stages the 



246 



