38 The Canadian Horticulturist. 



Prof. Cook gives some good hints on the method of jarring, which may be 

 useful to those of our readers who wish to experiment for themselves as to the 

 comparative merits of these two modes of combatting the curculio, therefore we 

 give the following extract from this bulletin : — 



The method of jarring is, in short, to place a sheet under the tree and give the tree, or 

 in case it is quite large, each branch, a quick, sharp blow. The insects fall to the sheet 

 and are easily gathered and crushed. 



The sheet may be mounted on one or two wheels, like a wheelbarrow, in case of large 

 orchards. The frame holding the sheet may be so made as to give the form of an inverted 

 umbrella, and a narrow opening opposite the handles will permit the centre of the sheet to 

 reach the trunk of the tree. A cheaper, simpler and more common arrangement is to have 

 two sheets on light rectangular frames, which, when brought side by side, will form a 

 square large enough to catch anything that may fall from a tree under which the sheet is 

 placed. If each frame has a square notch in the centre of one side they may be brought 

 close together about the trunk of the tree, so that the sheets will surely catch whatever may 

 fall. With two men to carry these frames and a third to do the jarring, the work proceeds 

 with great speed. Less than a minute is required per tree. In case one has only a few 

 trees, and no help, the sheet may be square, and slitted from the middle of one side to the 

 centre. Opposite this side it is tacked to a light, slender piece of wood, and opposite this 

 it is tacked to two similar strips, each one half the length of the side. This makes it easy 

 to carry the sheet, to place it entirely around the tree, and to roll it up, in case we wish to 

 set it away in a barn or shed. Of course the sheet should always be large enough to catch all 

 that falls from the trees. 



The mallet with which we strike the tree or limb should be well padded and carefully 

 used, so as not to wound the tree, or may be iron or wood unpadded, in which case a bolt 

 or spike is driven into the tree to receive the blow. Sometimes a limb may be sawed off 

 to receive the blow. I have used the padded mallet successfully for years with no injury 

 to the trees. I find that I can fell all the beetles to the sheet with such a mallet. Unless 

 we are very careful, however, in the use of the padded mallet we may do serious damage 

 to the trees. 



When two carry the sheet, and a third party uses the mallet, we may jar several trees 

 before we stop to catch and crush the insects. 



It is usually cool at the early or late hour, and the insects are rather sluggish and 

 will generally remain motionless for some minutes. If one uses a sheet like the last 

 described above, it is, perhaps, best to kill the insects each time after jarring. In case of 

 the wheel-sheet there is sometimes a box placed at the centre, and the inclined sheet makes 

 it possible to shake the beetles from the sheet into this box. I am not sure but this is 

 better in theory than in actual practice. The curculio may be brushed into a vessel con- 

 taining kerosene, or crushed between the thumb and finger. 



The expense of jarring will, of course, depend upon the excellence of the apparatus, 

 and upon the skill and quickness of the operators. Our largest and most successful plum 

 growers in Michigan estimate the expense at about ten cents per tree. I inquired of 

 several of our best pomologists and the estimates run from five to fifteen cents per tree per 

 season. Surely this is not an extravagant amount. 



In conclusion, let me say that I believe it would pay all our fruit growers to set plum 

 trees thickly among the other fruit trees of the orchard, and then to fight this insect as 

 described above. This will not only secure a fine and very profitable crop of this luscious 

 fruit, but will at the same time tend to protect the other fruits from this scourge of the 

 careless orchardist, without extra expense. 



It is rather a comforting idea, this of Prof. Cook's, that the curculio is to be 

 classed among the friends of the fruit grower, being an assistant to him in the 

 much neglected work of thinning his fruit. Certainly one who works for nothing 

 and takes his pay in waste fruit ought to be entitled to some consideration ; but 

 we fear it will be some time before our plum growers will look upon this insect 

 otherwise than an as enemy. 



That Paris green is a failure in preventing his injurious operations will, as 

 yet, be hardly taken as proved by some of our Canadian plum growers, until 



