REPORT OF THE ENTOMOLOGIST AND BOTANIST. 



207 



Canada, and the most approved remedies so far tried ; also to answer briefly some of the 

 pertinent questions frequently asked by correspondents and others concerning it. 



What is the San Jose Scale ? — It is a very small (the largest specimens, not more 

 than ^-inch in diameter) round, flattened and inconspicuous scale-insect ; that is, like 

 the well known Oyster-shell Bark-louse and the Scurfy Bark-louse, a sucking insect 

 covered by a waxy scale, which, as we find it on trees, is the only part visible, except in 

 the early larval stage, when scale insects for a few days have the power of walking. 



What it is not. — From the many different kinds of insects which have been sent in, 

 it seems advisable to state that the San Jose Scale is not an easily seen insect resem- 

 bling a beetle, a grub or a spider, nor has it well-developed wings and legs, but it is a 

 minute creature which can only be detected by the closest examination, and even then 

 requires some skill and experience to recognize it as an insect. 



Among the objects which have been received under the supposition that they might 

 be the San Jose Scale, were many things which in no way resembled scale-insects ; but 

 some, such as the small corky excrescences known as lenticels, which are found upon the 

 young bark of some trees — apples, pears, birch, walnut, &c. — and certain minute fungi 

 which are found on dead wood, (jio bear some resemblances to scale insects. Their 

 different nature, however, may generally be easily detected by the fact that they cannot 

 be detached from the bark without tearing the tissues, whereas all scale insects may be 

 removed easily from the surface of plants by a gentle pressure. 



How to know it. — The general appearance of the bark of infested trees is dirty, 

 scurfy and grayish in colour, as though dusted with ashes. The scales usually are found 

 in enormous numbers, frequently overlapping or occurring altogether on the top of other 

 scales ; they may be found throughout the summer of all sizes from the newly hatched 

 mite-like larvae to the fullgrown insects. In severe cases of infestation this massing of 

 the scales produces a scurfy, dirty appearance of the bark, which when once seen is 

 easily recognized. On young twigs, fruit and leaves, there is usually a well defined 

 purplish ring surrounding each scale which is sometimes useful for detecting its presence 

 when the scale itself might be overlooked ; and although this purpling eflect is produced 

 by a few other scales, such as the Putnam Scale {A. ancylus, Put.) and the Forbes 

 or Cherry Scale {A. Forbesi, Jnsn), it is particularly characteristic of the San Jose 

 Scale, and even upon large branches, although invisible at the surface, may be found by 

 cutting away some of the outer bark. 



The scales of the males and females differ somewhat in shape. 



Female : — Scale very thin, almost circular in outline, much flattened; size ranging 

 from 2V to ^ of an inch in diameter ; white at first, becoming grayish or blackish, par- 

 ticularly in the centre, and later much blackened by the fungus Fuinago salicina, so 



common on trees attacked by many kinds of bark-lice and 

 plant-lice. In the centre of the scale there is a small dark, 

 or when the insect is dead or rubbed, yellow, nipple-like 

 elevation surrounded by a distinct circular depression, 

 which, as pointed out by Prof. Webster, is one of the best 

 distinguishing marks between this scale and some closely 

 allied species. 



Male : — Scale about half the size of that of the female, 

 rounded-oblong, with the nipple-like elevation plainly nearer 

 to one end than the middle. 



The drawing herewith shown was made by Dr. C. E. 

 Saunders from a group of scales found upon a plum on 25th 

 of July last. They are all, therefore, of the first brood of the 

 season, although certainly some of them were born later 

 than others. The first young of the year were reported 

 aSfe^i;?:nliSi^£;;^. from Niagara on 1st of July, so th^ thelaxgest specimens 



would be about three weeks old. This was by Mr. 

 Charles Thonger, a careful observer. Male insects almost ready to emerge from their 

 scales, were found among the scales shown in the figure. 



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