INSECTS INJURIOUS TO THE STRAWBERRY 443 



aphides of the first generation become full grown in twelve to 

 fifteen days. The adults soon commence to give birth to young 

 aphides, bearing fifteen or twenty within a few days. All of the 

 aphides of this generation are females, as are all those of the 

 summer generations, the males appearing only in the fall. The 

 young of the second generation mature and reproduce in the same 

 manner and in about tfte same time as the first generation. Until 

 the last of April but few ants are seen, but about that time they 



FIG. 317. Eggs of strawberry root-louse on leaf stem. 



become active and carry the young aphides from the leaves 

 down to the roots, where a colony of a dozen or more is established 

 on each plant. No aphides are found on the roots until the ants 

 appear, and they are entirely responsible for the aphides infesting 

 the roots. The ants continue to care for the aphides during the 

 summer, carrying them to new plants when they become over- 

 'crowded or the plant dies, and so are responsible for the spread 

 of the pest. The first generations are entirely wingless, but when 

 the third generation matures a large number are winged. These 



