No. 7. DEPARTMENT OF AGRICULTURE. 617 



over the ground, for in young trees, it is especially at first found upon 

 the trunks of the trees, and upon the under branches. To illustrate 

 its slow movement from tree to tree, in 1900, in a row of trees on 

 the writer's property, two trees were infested, and the scale be- 

 gan to travel along the row. Now, although the branches interlace, 

 the scale has not yet reached the ninth tree, which is to-day free 

 from the scale. 



The wind may possibly sometimes waft it to nearby plants. 

 Possibly it travels on ants, or other small insects. Some are 

 (luite sure that, it is conveyed upon the horse used in working or- 

 chards, but this does not seem to the writer probable. Birds, and es- 

 pecially the English sparrow, have been credited with spreading the 

 scale. If this is so, then it would seem that it makes use of birds, as a 

 vehicle, as little as possible. Against the bird-conveying theory, 

 we would urge, first, it is commonly found upon the under branches 

 of a tree first, in a word, in the places where birds would be least 

 likely to alight. Second, the scale selects its host, or plant on 

 which it will live. If careful to do this, is it not also careful to se- 

 lect the vehicle by which it travels? We think so. Thus it avoids 

 the cherry, the Kieflfer pear, and forest trees generally, while it 

 selects for its home the currant bush, Japan plum, Japan quince, 

 Ben Davis apple, Seckle and Anjou pears, and the Kosaceae family 

 generally, though there are exceptions. 



But if we do not know how it gets from tree to tree, we do know 

 how it has been spread over the State. It came to the writer's 

 property on nursery stock, and it has been carried all over the 

 State in the same manner. All know that this was true in the 

 past. It is still true. During the past summer the writer visited 

 three nurseries in this State, all recently infested from jmrchased 

 stock, one from Maryland, one from Iowa, and one from New York. 

 In all cases our nurserymen thought they were getting clean stock, 

 and for a time, at least, they disseminated infested stock, not know- 

 ing that they had the scale. 



There are still dealers in trees who do not believe the scale to be 

 really dangerous. Such do not hesitate to sell infested trees where- 

 ever they can. There are others who place the burden upon the 

 State, claiming that after they receive a certificate of freedom from 

 scale, they are free to sell, without further concern, even though 

 the scale may be afterward found upon their stock. 



The scale is nearly miscrocopic in size. It may escape a hasty in- 

 spection and a careless fumigation. It does so escape. The fact 

 is, that to-day after all that has been written and done,scale in large 

 quantity is being disseminated on young stock, and will be so dis- 

 seminated until greater care is taken with both inspections and 

 fumigations. Dealers need much fuller instructions upon fumiga- 

 tion, and it is a question whether or not all fumigation should not 

 be done under State inspection. 



Another matter that should receive attention. A nursery once 

 infested should ever after be required to fumigate all its stock, or 

 such stock as the insect inhabits. So difficult is it to find the minute 

 insect, that this precaution is a necessity. 



Inspections should also be delayed so far as possible until after 

 the leaves have fallen, for it is well nigh impossible to do good 

 work with the trees covered with their foliage. It is the opinion 



