ENTOMOLOGICAL SOCIETY OF ONTARIO. 79 



Since that article was written it has been seen how well founded were the fears that 

 this dreaded enemy might spread to Canada and be a cause of loss in our fertile fruit 

 districts. 



The San Jose scale, it is thought, was introduced into California about 1870 ; but it 

 was not noticed as a serious enemy until 1873, when it was discovered to be in great 

 numbers on fruit trees at San Jose, Cal , a fact which has given to the insect its popular 

 name. Its original home is not certainly known, but Japan is suspected. 



As far as can be learnt, it had not been scientifically described until 1880, when Prof. 

 Comstock treated of it in his annual report as Entomologist to the United States Depart- 

 ment of Agriculture. Dr. L. O. Howard tells us that Prof. Comstock designated it by 

 the specific name pemiciosus because he considered it the most pernicious scale insect 

 known in the country. " It swarmed in countless numbers upon the trees in certain 

 orchards, and infested all the deciduous fruits grown in California except the apricot and 

 the Black Tartarian cherry. In the course of twelve years the insect spread through all 

 the fruit growing regions of California, through Oregon and into the State of Washing- 

 ton. It is known as the worst insect pest of deciduous trees on the Pacific coast and has 

 caused great pecuniary loss. Many crops of fruit have been ruined and thousands of 

 trees have been killed." 



The above was written by Dr. Howard in April, 1893, since which time a great deal 

 more than was then known has been learnt concerning this insect; and its capabilities as 

 an enemy to the fruit grower. It has been introduced into the east and, contrary to 

 expectations, has shown that the climate of the Eastern United States is sufficiently well 

 suited to its requirements for it to have developed so rapidly and with such deadly effects 

 upon the trees infested that it has now become of national importance. It is at the 

 present time acknowledged to be by far the most serious insect enemy of fruit trees which 

 has ever been studied by practical entomologists. Owing to its very inconspicuous appear- 

 ance and to the fact that it passes the winter attached firmly to the bark of fruit trees, it 

 has been distributed widely and unwittingly by nurserymen with young fruit trees and 

 now occurs in almost every State of the Union. It has also spread up into Canada, 

 where it has been found on two or three occasions in British Columbia and has also estab- 

 lished itself at a few places in the peach districts of Ontario. The first specimens of this 

 insect received from an Ontario orchard were from the vicinity of Chatham in Kent 

 county. This was in January, 1897. Very soon afterwards it was discovered that there 

 were other orchards near Niagara and St. Catharines which had been similarly infested 

 through fruit trees imported from the United States. The last discovered occurrence 

 of this insect was made quite recently near Kingsville in Essex county, where three cen- 

 tres of infestation were found on one fruit farm, involving upwards of 300 trees. The 

 above are all the authentic instances of the occurrence of the San Jose scale in Ontario 

 which I have been able to learn of, although at various times during the summer several 

 reports of infested orchards have been received. Upon investigation, however, these have 

 proved to be occurrence s of some other scale insect. In addition to several kinds of scale 

 insects which were sent in for identification under the supposition that they were the San 

 Jose" scale, many other insects in no way resembling a scale insect were sent. From the 

 many kinds of these belonging to various orders, it seems advisable to state that the San 

 Jose scale is not an easily seen insect, resembling a beetle, a fly or a spider, nor has it 

 well developed wings and legs, but it is a minute creature which can be detected only by 

 the closest search and even then requires some skill and experience to recognize it as an 

 insect. Among the objects which have been enquired about were many things quite 

 unlike scale insects, but there were others which certainly do present very much the same 

 appearance. Among these were certain minute fungi found on dead wood, and particularly 

 the small corky excrescences known as lenticels which occur upon the young bark of many 

 trees, as the apple, pear, birch, black walnut, etc. Their different nature may, however, 

 be generally ascertained easily by the fact that they cannot be removed from the bark 

 without tearing the tissues, while scale insects may be easily moved by gentle pressure as 

 with the finger nail. 



