A Plum Scale. 693 



of the San Jos Scale on their backs ; curiously enough, the scales 

 seemed to prefer to ride on the backs of the shining black beetles 

 and ants rather than on the red ones. 



Doubtless the wind is an important factor in the spread of this 

 pest. Possibly a strong wind may detach some of the scales and 

 carry them to other trees. The wind also distributes the fallen 

 leaves over a considerable area in the fall ; and as many of these 

 leaves contain a few hibernating scales, they would form a fruitful 

 source of contagion. We estimate that about 10 per cent, of the 

 scales are hibernating on these leaves, and many of them will 

 doubtless find their way onto the nearest trees in the spring. 



Is there danger of ijitroducing it on nursery stock f — Some news- 

 papers, in commenting on our recent popular discussion of this 

 scale in the Rural New Yorker and other papers, have warned 

 their readers to carefully examine all nursery stock sent out by 

 New York nurserymen lest the scale be introduced into their 

 orchards in this manner. This is a very important point, and was 

 made the subject of special investigation and inquiry in our recent 

 trip through the infested region. The result is that, so far as we 

 now know, there is but little danger of introducing the pest into 

 new localities on nursery stock. Nursery men rarely have the stock 

 more than two years, and it is not usually grown near plum 

 orchards. And furthermore, we have never seen or heard of the 

 scale on any except bearing trees. We have not found it on trees 

 which have been set less than five years in orchards. It is always 

 a wise precaution, however, to examine thoroughly all nursery 

 stock for scales or even borers. You need not expect to find this 

 Plum Scale, but remember that the dreaded San Jose Scale is 

 abroad in the east and may be introduced on nursery stock. Dig 

 out the borers and dip the trees in a strong kerosene emulsion to 

 kill the scales. 



ITS NATURAIv ENEMIES. 



This Plum Scale doubtless has several insect enemies, but we 

 have met with only two thus far. In May, there were many 

 small, narrow, smooth, elevated, black scales scattered among the 

 nearly full grown females. Some of these small black scales can 



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