SUMMER MEETING. 87 



In order to effectually fight these pests, we need to know their life history, 

 and especially where they spend the fall, winter, and spring months, 

 when the trees are destitute of foliage. 



Many mites pass the winter in moist places, under leaves and 

 stones, and other rubbish, and it is possible that some of the 

 Phytopti do likewise. Mr. Garman, of the Illinois State Uni- 

 versity, has proven that many of these mites hibernate upon the 

 twigs, and within the buds of the infested trees. He found he 

 could obtain the mites at any time during the winter by taking the 

 JV/ twigs of an infested tree into a warm room. 



- — The Phytoptus galls upon the leaves of the soft and hard maples, 



FlG - 5 - the basswood, the elm, and the plum are probably most familiar 

 here. Upon the soft maple they are especially abundant, causing the leaves to 

 present a warty appearance; while on the hard maple, basswood, and elm they 

 are much drawn out in length, and stand erect upon the upper surface of the 

 leaves. 



The many different Phytoptus mites, as well as the galls they produce, are 

 so similar that a description of one will enable us to recognize almost any 

 other. 



The pear-leaf blister which sometimes does a considerable harm, is due to 

 one of these mites, Phytoptus pyri. 



The remedy recommended most commonly for these pests is fire. The 

 infested twigs may be gathered in winter, and the infested leaves in summer, 

 and burned. 



If it is true, and I believe it is, that most of these mites hibernate upon the 

 twigs and buds of the trees, I can see no reasou why strong soap suds, kerosene 

 emulsion, or sulphur might not be applied with excellent results. 



Another injurious mite with which nearly every one is more or less 

 acquainted, is the common red spider, so troublesome in green-houses. This 

 little mite, for it is not a spider at all, was named by Linuseus, Tetranyclius 

 telarius. Its depredations are not confined to tne green-house, but during pro- 

 longed drouths in summer, it has been known to attack the strawberry, the 

 rose, the peach, the pear, and many other trees and plants. During the drouth 

 in the summer of 1871, which preceded the great Chicago fire, the evergreens 

 upon the College grounds were literally red with myriads of these little crimson 

 pests. 



The red spider belongs to the family Trombididcs. They are also known as 

 spinning mites, as they cover the under side of the leaves on which they live 

 with a delicate web, which serves as a protection rather than a snare to trap an 

 unwary fly. 



The name red spider is misleading, not only because it calls a mite a spider, 

 but because it calls what is usually a green mite a red spider. The scarlet 

 color is supposed to come with age. 



The remedies for this pest are sulphur or strong soap suds, or both mixed. 

 Sulphur laid upon the pipes in green-houses is highly recommended. But the 

 cheapest, and in most cases probably the best remedy, is pure cold water. Prof. 

 Cook reported complete success with the cold-water cure, as applied by him at 

 the Agricultural College in 1871. 



If only a few plants are troubled, they can be ridded of the pests very easily 

 by setting in a damp, cool, room for twenty-four or forty-eight hours. Cold 

 and moisture are fatal to them. 



