17 



in the tree; but iniglit it not possibly exercise an indirect effect? The 

 Keift'er among pears is the least troubled by this borer, because it 

 repairs damage almost as rapidly as it is caused, and quite usually 

 crushes the working larva in its channel, so that it is only rarely that 

 the beetle matures, unless the tree is otherwise weakened. By stimu- 

 lating growth when the larvie are young and least able to resist, by 

 means of an excess of readily available fertilizer, it is not impossible 

 that results may be obtained that seem now to be quite out of our 

 reach. That some trees do carry in their sap an excess of certain solu- 

 ble substances 1 am convinced from my own observation, and this is 

 not contrary to the teachings of plant physiology; but actual knowledge 

 of the matter is scant, and we have rather an indication of a line in 

 which experiments may prove ]:)rofitable than results upon which we 

 can base conclusions. 



I have noted an increasing tendency of late to attempt the control 

 of insect pests by methods of cultivation or farm practice, and this, in 

 my ojunion, is much to be commended. There are periods in the life 

 histories of many insects when they can be easily reached if we only 

 know how, and where resort to some simple bit of field i^ractice may 

 prevent injury. A good example of this is seen in the practice of cut- 

 ting close to the surface all shoots of blackberry about June 20 to pre- 

 vent injur}' from the Agrilus ruficoUis. All the eggs have been laid at 

 that time, and the new shoots will be exempt, of course, while the larvie 

 can not develop in those that have been cut down and will die. The 

 whole matter seems so simple now, and yet it is less than two years ago 

 that this was practiced almost simultaneously in Xew Jersey and Ohio. 



Preventing injury from tlie larvte of Melittia veto in late squashes by 

 planting summer varieties upon which the eggs are laid and in which 

 the larvie are afterwards destroyed is another method which has been 

 worth many hundreds of dollars to farmers on Long Island and in New 

 Jersey. 



But there is yet much to be done in this direction, and I am convinced 

 that in the future "circumvention" will be practiced in many cases 

 where we now use poison. Farm practice, using this term in its widest 

 sense to include the mechanical treatment of land, selection of ferti- 

 lizers, date of planting and harvesting, rotation of crops, etc., will in 

 time give us control of many injurious species which at present seem 

 beyond our reach. It must be our aim to ascertain as far as possible 

 the circumstances least favorable to the development and maintenance 

 of the troublesome species, and then our attem[)t must be to produce 

 just those conditions. 



We should, 1 think, whenever possible, lay great stress upon the 

 imi)ortance of destroying crop remnants when they are no longer 

 needed. For instance, cucurbit vines are usually left on the ground 

 after all the crop is off, aifording abundant o])portunities for the 

 maturing of A /m.sY/ tristis, the melon lice, and other pests. Kemoving 

 6042— Xo. 2 2 



