NINETEENTH ANNUAL MEETING. 23 



the reproductive power of these insects. I took the trou- 

 ble to study into a statement which was made by one 

 of the older entomologists, Thomas, I think, that if the 

 progeny of a single aphis which came out in the spring 

 were left alive to reproduce that by fall, if they were 

 placed side by side, they would cover the face of the earth 

 for several inches deep, and they would reach' from the 

 earth to the furthest star. That seems quite a story, but 

 there is some foundation for it. It is enormously repro- 

 ductive. If any of you doubt it, just take a pencil and 

 figure out the result from the rate of reproduction. It is 

 really marvellous. So we must recognize that with the 

 San Jose scale and with pests of this character, these 

 smaller forms of insect life, there is an exceedingly rapid 

 rate of reproduction. This is simply shown to give you 

 an idea of their effect on young apples, where the aphis 

 has clustered over the young fruit. 



Here is a leaf which was covered with the aphis. This 

 particular leaf is of interest because the individuals shown 

 upon it were a bright orange color instead of the normal 

 green that they usually have. It simply shows a view 

 of the way the foliage is curled up by the aphis in the 

 spring, and this other view is the same thing only it shows 

 the effect on a tree which has been largely defoliated. The 

 injury is the greatest on young trees. Old trees, although 

 infested, do not suffer much, but young orchards up to 

 eight or nine years of age are seriously injured by this 

 aphis. 



Now as regards treatment, there is just one time when 

 you can spray for that insect, and that is as the leaves are 

 coming out in the spring. If you make an application of 

 the spray after the leaves are curled up it is almost im- 

 possible to penetrate inside of them so as to reach the pest. 

 Although you can kill a good many of them, a great many 

 escape. If the spray is applied before the foliage has ex- 

 panded to any great extent, or before the insects have 



