REPORT OF THE ENTOMOLOOIST AND BOTANIST. 221 



Whatever the reason may be for this great difference, the value of the remedy for the 

 "West is undoubted and well attested. Similarly, the gas treatment has given less satis- 

 faction in the East than on the Pacific coast, but this is to some extent due to the diffi- 

 culty of treating deciduous trees, such as are infested by the San Josd Scale, which have 

 a more spreading, open growth than the close-growing, thick-foliaged trees of the Citrus 

 family, upon which this method is chiefly used in California for other kinds of scale- 

 insects. For the disinfection, however, of nursery stock, the gas treatment is certainly 

 most convenient. Probably the remedies which will be found most available for Ontario 

 fruitgrowers will be the whale-oil soap wash and the kerosene emulsion. The latter 

 should be applied as soon as the leaves drop or during the winter, made according to 

 the Riley-Hubbard formula and diluted with only four parts of water, to be followed 

 before the leaves expand in spring by the whale-oil soap wash, 2 pounds in 1 gallon 

 of water. 



Mention may be made of the fact that where trees are closely planted the scale has 

 spread more quickly than where the trees are farther apart. This points to the advan- 

 tage of having the trees planted as wide apart as possible without waste of land. 



Since the San Jose Scale is already established in several centres in Ontario, it is 

 now too late to prevent its introduction into the country ; still, no effort should be 

 relaxed which will prevent further importation from infested nurseries in the United 

 States, and it should not be forgotten that nearly all of the Canadian outbreaks have 

 been traced back to nurseries in the State of New Jersey. There are some precautions 

 which common sense would seem to dictate to all fruit growers, such as : (1) Do not buy 

 either from nurseries known to have been infested, or, as it is unnecessary, even from 

 States where the scale is known to exist. The homegrown trees of all our Canadian 

 nurseries are much safer to purchase than those coming from any of the usual sources 

 in the United States. Up to the present not a single Canadian nursery has been found 

 to be infested. 



(2) Examine all trees upon your own grounds and upon your neighbours', particu- 

 larly those which have been planted or grafted during the last five years. 



(3) Plant no young trees without examining them carefully for any trace of the 

 San Jos^ Scale. Should any case of infestation, or even suspected plants, be found, at 

 once report the matter and send specimens for examination to the Government entomo- 

 logists at Ottawa or Guelph for advice. 



On account of the exceedingly inconspicuous nature of this enemy and its habit of 

 hiding beneath scales of bark, buds, etc., as well as the extreme danger which attends 

 its introduction, in those cases where it is considered necessary to purchase from 

 American nurseries, it would be well for fruit growers not to trust to the certificates 

 that the trees are free from scale, which are sometimes supplied by nurserymen, unless 

 the}' are actually signed in writing by state entomologists of recognized standing, and 

 also for the actual consignment of trees with which they are imported. 



As an illustration of the difficulty of detecting the young scales when they are few 

 in number. Prof. F. M. Webster has published an illustrated article in the current 

 December number of Entomological News, showing a twig from a peach tree which had 

 been submitted to him for inspection and of which he says : " The most diligent search 

 with a lens failed to reveal any outward trace or indication of the presence of San Jos^ 

 Scale. When one of the buds was removed it was found that there was behind it a half 

 grown scale which had been completely covered and concealed by the bud." This 

 showed that practically no one could be certain that a tree was absolutely free from 

 scale without removing all the buds, which of course is out of the question. 



