STATE HORTICULTURAL SOCIETY. 223 



late as the 18th and 20th. blighted a good deal, losing half or more of 

 tlieir tops, and one of thcni died quite down to the ground. From what 

 has been explained, here and previously, it will be seen that when trees 

 are to be root-pruned to prevent injury from blight, it must be so per- 

 formed that the trees can not extend their branches after the time blight 

 is expected. Or when blight is likely to appear early, summer pruning 

 must be done the previous season. Here perhaps it will be well to state, 

 that when the pruning is delayed until the 20th of May, double the 

 amount of roots would have to be cut, to force a tree to rest by the first 

 of June, that would have been required if the operation had been done 

 before the trees leaved out. 



If, however, as before intimated, our object in pruning be to secure 

 early fruitfulness of the trees only, then we can see no objection to delay- 

 ing the operation until such time in tlie summer as trees have made a 

 fair growth, or until about the time the alburnuni is forming rapidly. 



If, however, the trees are pruned at this late period, the soil under 

 them must be kept carefully stirred, otherwise little or no root growth 

 w ould be formed until the following year. 



Al'PLE-TKEP: PLANT LOUSE [Apkls mall). 



During the past summer several packages of diseased apple leaves 

 w^ere received, to each of which a reply similar to the following was 

 made. The leaves were in precisely the condition that the leaves of many 

 varieties were in this region last year. Each diseased part has a center, or 

 several of them, caused by punctures of apple tree lice. On the most of 

 these leaves the punctures were made while they were unfolding, before 

 the under side was accessible to the lice, probably before the trees were in 

 bloom or very soon after. 



The eggs of the louse, wdiich is the cause of this mischief, as well as the 

 louse itself, are preyed upon by quite a small bird, early in the spring; at 

 the same time, and later, by the lady bugs and their larvai. Also by the 

 larvie of lace-wing flies, and other cannibal insects. Last year, through- 

 out a consideral)le part of Illinois, the apple-tree louse infested trees in such 

 vast numbers as almost to conceal the young branches, yet within five or 

 ten davs after tiie larvic of the lace-wing flies appeared among them, 

 scarcely a louse could be found. At the time of the disappearance of the 

 lice, and for several days afterwards, their punctures were not perceptible 

 to the unaided eye. With the help of a good lens, however, the wounds 

 made by them were plain to be seen. It was also apparent that as soon as 

 a louse was removed, the puncture it made in sucking the juices of the 

 leaves, became a nidus or point to which that species of fungi which 

 clouds the fruit, became attached. 



As seen, when highly magnified, the spores of this fungus w^ere 

 heaped up manv deep, and spread rapiilly around the wounded part, 

 until th(j the diameter of the patch would be an eighth of an inch or 

 more. Another noticeable feature of the spread of this rust the past year, 

 was that when it became largely multiplied around wounds, it spread to 

 healthy leaves, tender branch growth, and to the fruit. 



