INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



197 



Control. — Control measures are same as for the greenhouse white 

 fly and are very unsatisfactory, even when the entire tops are cut 

 and burned, as reinfestation occurs as soon as the new growth appears. 



Fig. 173. — The iris white fly. Aleyrodes spirwoides Quaint. 

 Eggs, larva?, nymphs and adults on iris. Enlarged twice. 

 (Original) 



THE GREENHOUSE WHITE FLY 



Astcrochiton vaporariorum (Westwood) 

 (Aleyrodes vaporariorum Westwood) 



(Fig. 174) 



Description.— The adult female white Hies are about -^ inch long, 

 the males being slightly smaller. The bodies are yellow and the wings 

 pure white. The eggs are exceedingly small, oblong in shape, at first 

 light green, growing black with age and attached by a short stipe. The 

 larvae are light in color, transforming to fiat nymphs about 3-100 inch 

 long, oblong-oval in shape, light green and supporting noticeable wax- 

 like rods or spines, which makes this species readily distinguishable 

 from all others. 



Life History.— The eggs are laid upon the Leaves of the plants, each 

 female depositing over one hundred. These batch in about two weeks 



