312 The Canadian Horticulturist. 



reports that some of his plum-trees have been killed by it, but no instances of 

 this kind have yet come under my observation. When it occurs in such num- 

 bers as to nearly cover the bark, as shown in Fig. 692, there can be no doubt 

 that it is capable of injuring the trees. This illustration is from a photograph 

 of an infested branch of the Bradshaw plum. On the twig at the right are seen 

 scars showing where some of the scales have been removed. The actual length 

 and width of a full-grown scale is indicated by the cross lines in the illustration. 

 The dimensions are usually about five millimeters by four — that is to say, about 

 seven thirty-seconds by five thirty-seconds of an inch. 



At the present writing, June 20th, the scales are filled with a whitish 

 powder, which, examined with a lens, proves to be composed of eggs. The 

 young lice which are produced from the eggs in the spring had already issued 

 from the old scales this season about May loth, when my attention was first 

 called to the insect. The branches were then covered with a sticky substance 

 like honey-dew, evidently secreted by the young insects. On leaving the old 

 scale they crawl over the branches till, finding a convenient location, they attach 

 themselves to the bark. They seem to prefer a location on the under side of 

 the limbs. At first they are whitish, or nearly transparent, but gradually assume 

 the dark reddish brown color of the mature insect. 



Mr. L. O. Howard, the United States Entomologist, to whom specimens 

 were submitted for identification, states that it is a somewhat rare species known 

 as Lecanium cerasifex. He advocates spraying with dilute kerosene emulsion 

 when the young insects first appear in the spring. The scales are soft and easily 

 loosened from their attachment, and might readily be brushed or scraped from 

 the larger branches. 



Thus far I have seen the insect in Niagara, Monroe and Ontario Counties, 

 indicating that it is quite widely distributed in Western New York. So far as I 

 have observed, plums are most seriously attacked, though the insect has also 

 been found on apple, pear, maple and cissus, showing that it has a wide range 

 of host plants. 



Pear leaf blister mite. — Prof. Sleugerland, of Cornell University, has 

 discovered a simple remedy for this mite, in the application of kerosene emul- 

 sion. In September, 1892, 16 trees were selected and labeled, and in March, 

 1893, were sprayed with herosene emulsion diluted with from 3 to 10 parts of 

 water, 2 trees being left as checks. On July 10, the 2 trees which had not been 

 sprayed were badly infested. The results on the others showed that the emul- 

 sion was effective when diluted with not more than 8 parts of water. The 

 author concludes that the pear leaf blister can be nearly or entirely exterminated 

 in a badly infested orchard by a single thorough spraying of the trees in winter 

 with kerosene emulsion diluted with from 5 to 7 parts of water. 



