116 MASSACHUSETTS HORTICULTURAL SOCIETY. 



ground be laid down to grass again before the insects peculiar to 

 the crop raised become established, the rotation of crops will be 

 beneficial for more reasons than one. 



I have no doubt that lands which are said to be run out are 

 very often rendered so by the numerous insects on them rather 

 than b}'' the poverty of the soil. I have known many cases where 

 grass lands failing to yield a fair crop were broken up and culti- 

 vated for a time and laid down again with but very small applica- 

 tions of manure, and yet a large hay crop followed for several 

 years. I cannot rid myself of the conviction that many of these 

 cases are due to the work of insects more than to the poverty of 

 the soil. 



Discussion. 



Professor Fernald remarked in the course of his lecture that in 

 the State of New York a much larger percentage of apples has 

 been saved from injury bj' the codling moth than was stated by 

 Professor Forbes. There are two species of canker worms, one 

 found in fall and the other in spring, and in both species the male 

 and female are very different. At Amherst, Mass., they have only 

 the spring canker worm ; at Orono, Maine, only the fall. The 

 female of the tussock moth never goes down from the trees. 



The lecture was illustrated by specimens of insects and force 

 pumps for applying insecticides. A hydrant does not give a con- 

 tinuous spray. One pump, with a flat nozzle, having six fine 

 holes, possessed the advantage that with it one could take a pail 

 on his arm and climb up into a tree and use it there. Another 

 pump with an air vessel, giving a continuous stream, would throw 

 the insecticide to the tops of apple trees. It had two nozzles, one 

 of them being reversible. The Professor thought a broad, flat 

 stream preferable to one of cylindrical form. One pump, to be 

 set in a pail, had the disadvantage of lifting with ever}- upward 

 stroke, unless it was firmly held down. Another was provided 

 with a place to put the foot on to keep it steady. 



O. B. Had wen said that he had been much interested in the 

 lecture, for unless we can successfully contend with insect enemies 

 we cannot raise perfect fruit or flowers. The codling moth is 

 known to all cultivators of fruit, and he was glad to hear that it 

 can be eff'ectuall}' destroyed by Paris green or London purple. He 

 had used pyrethrum in solution to destroy insects. He mixes it 



