56 



ber all stages could be found on the leaves. In the spring of 1903, 

 two adults, recently emerged from their pupa cases, were found on 

 May 4, but it was over a week later before the adults became at all 

 common. In some seasons the strawberry Aleyrodes will be much 

 more abundant than in others, owing to the varying weather condi- 

 tions. A cold March, unfavorable to the development of the eggs, 

 will delay the time of hatching until the larvee will be less liable to 

 be cut off by the spring frosts, while a couple of weeks of warm 

 weather in March, followed by a cold snap, will cause a large num- 

 ber of the eggs to hatch and the resulting larvae to die, and conse- 

 quently comparatively few adults will result from the wintering over 



eggs. 



Of those larva? which are fortunate enough to escape destruc- 

 tion by the frosts only a small proportion. reach maturity, as most of 

 the old leaves upon which they feed and from which they are unable 

 to move, are dead before the insects reach maturity. Considering, 

 however, the enormous number of eggs which are deposited upon 

 the leaves in the fall it is evident that if only one adult results from 

 each one thousand eggs, the number left to continue the species will 

 still be large. 



ECONOMIC IMPORTANCE OF THE STRAWBERRY 



ALEYRODES. 



The only serious injury thus far reported as resulting from the 

 attacks of this insect has been from the state of New York. The 

 following quotation from Slingerland (9) shows the amount of injury 

 the insect may do : 



" In the fall of 1897, and again in July, 1900, we received speci- 

 mens of strawberry leaves which were seriously infested with a pe- 

 culiar scale-like insect. The first specimens came from Sparkill, 

 Rockland county, N. Y., and those last year from Rossville, Staten 

 Island, or not far from the first. The following statements from 

 letters of our correspondents will describe the insects' work: 



' Our strawberry plants are full of very small white flies. They 

 seem to suck the sap out of the leaves ; they are on the under side 

 of the leaves, and when disturbed fly away. The leaves turn black 



