44 



So far as I know, the life history of EmpoaM-a tnall has not been 

 thorouiihly worked out. As far as the ajjple is concerned, it would 

 a])pear that the egg is laid by the adult in the tissue of tlie leaf, for 

 young of such a tender age as to jireclude the possibility of their 

 having migrated after hatching are found on the under side of the 

 leaf. In the absence of conclusive evidence, however, I hesitate to 

 i-egard the a])ove probability in the light of a fact. As you all know, 

 the leaves of nursery trees, as well as the more tender leaves in or- 

 chards, are curled by this pest, and the growth of the tree checked for 

 the time being. Last summer in jVIinnesota the insects began their 

 work early in July and soon grew very abundant. 



Mr. Stedman, of Missouri, who was present at the meeting in St. 

 l/ouis, chanced to remarlv upon his work along this line in his State. 

 This coincidence was a great help to me, for I at once proceeded to 

 get suggestions from him, which were most cheerfully given. The 

 general plan of his spraying machine I carried home with me, find- 

 ing, upon considering the matter, that this plan should be changed 

 somewhat to better subserve our purpose in Minnesota. 



It is to be noted that 3- and 4-year-old trees in Minnesota are not 

 as tall as they are in ^lissouri, hence we were not obliged to have 

 the cart quite so high aboA^e the ground. AVe found it best, also, 

 to bring the container off the platform which stood above the wheels 

 in order to make the cart more stable. The wheels of this cart are 

 5-> feet in diameter, with 4-inch tires, and the platform, which is 

 8 by 4:f feet in size, is 14 inches above the wheels and firmly bal- 

 anced on the axle, so that practically all the weight comes on the 

 axle and not on the horse. 



A glance at the accompanying illustration (fig. 2) will give one 

 an idea of the details. The pipe (Z>) is a 1-inch pipe 10 feet long. 

 On this pij^e four nozzles are attached, pointing directly downward 

 and so placed as to be 3^ feet distant from each other. This spacing 

 brings each of the nozzles directly over a nursery row, Avhere, as in 

 Minnesota, the rows are usually ?>^ feet apart. This pipe can be 

 raised or lowered mechanically to suit high or low trees. The hori- 

 zontal pipe (6') is 14 feet long and projects 10 inches back of the 

 platform, thus clearing the wheels. The five verticals from this pipe 

 {E) are made of f-inch piping, 5 feet 4 inches long, and there is also 

 a 3^-foot space betAveen these. The crosspieces at the bottom are so 

 arranged that a nozzle in each end of each piece points up at an 

 angle of about 45°. This sj^acing and arrangement of the nozzles 

 on both pipes residts in a copious spray coming both from above 

 upon the tops of the trees and from below against the lower surface 

 of the leaves — the latter, as you know, l)eing very important. In 

 actual practice the trees are completely surrounded by a fine spray, 



