57 



on the outer edges, where they are infested badly, and some plants 

 are nearly or quite killed by them. Certain varieties are more in- 

 fested than others.' 



' The leaves I enclose were taken from plants set this spring, 

 which have been attacked by small white insects on the under side 

 of the leaves,' writes our Rossville correspondent in July, 1900. 

 ' When I touched the plants, the flies, not larger than a grain of salt, 

 but perfectly white, would rise up by the thousands in clouds. The 

 plants started off vigorously with large healthy runners. Finally, I 

 noticed that the plants began to look dead, leaves began to die and 

 the runners began to wilt and dry up. Some of the plants are dead. 

 The patches that were in bearing were also found to be badly in- 

 fested later in the season. While picking the fruit the upper sides 

 of the leaves seemed glossy like varnish, and the pickers remarked 

 that their hands were covered with stickiness. Later on the plants 

 had a black smutty appearance. These plants were very vigorous, 

 but now the greater part of them have turned brown and died out 

 entirely.' " 



From my own observations I consider that the greatest injury 

 to strawberries by these insects is in the late summer and early fall. 

 The adults and immature insects are then very abundant, and though 

 comparatively few leaves are actually killed, the plants are percepti- 

 bly weakened and fail to develop good vigorous crowns and roots. 

 As a consequence, the following spring the new growth is retarded 

 and the fruit yield reduced. 



In the springs of 1902 and 1903 the insects did not become 

 sufficiently abundant previous to the fruit harvesting season to do 

 any appreciable damage to the fruiting vines. It seems, therefore, 

 that whenever the insects become of sufficient importance to require 

 treatment, that such treatment should be applied so as to prevent 

 the injury which takes place in late summer and early fall. 



TREATMENT. 



In considering the treatment of the strawberry Aleyrodes we are 

 confronted by two problems : How to prevent the insects from es- 

 tablishing themselves on newly set plants, and how to deal with them 

 when once they are present in large numbers. 



