11 



cies of scale by the red blotches which are formed wherever it stings any 

 part of the tree — either branch, leaf, or fruit. These red blotches are more 

 pronounced in some varieties than in others. When the scales are present 

 in large numbers it causes a complete discoloration of the bark clear to the 

 sapwood. This scale, like others, has its preference among the deciduous 

 fruits, which it affects most severely. The apricot is the only one which, 

 it may be said, is proof against it; certain varieties of cherries and plums 

 are but little aff"ected, the reason being, probably, that the bark is too com- 

 pact for the scale to pierce it with its proboscis. 



Plate I shows the appearance of the insect and its work on fruit, leaf, 

 and branch. 



HABITS OF PERNICIOUS SCALE. 



It is generally accepted as a correct statenient that this insect has three distinct broods; 

 one in June, one in August, and one in October, at which times all the scale eggs are 

 supposed to hatch. As might be expected, the time for these hatchings varies somewhat, 

 according to climate and locality, a warm location hastening the development. But what 

 is of more importance is, that all the insects evidently do not hatch out at once. During 

 most of the time of the growing season there can be found young insects crawling around, 

 though certainly at the periods stated they are most numerous. Yet, enough will linger 

 along between every two of these periods to prevent summer washings to be thorough 

 remedies, as the old scales are too well protected to be killed by anything that can be 

 applied in the summer. I believe this is the reason why persons have been so unsuccess- 

 ful in their treatment against these insects, and hence' I am of the opinion that winter 

 treatment, when we can apply remedies strong enough to kill the protected insects, is the 

 best time to accomplish the desired result. One most important point to be considered in 

 spraying is the size of the tree. While it is a comparatively easy thing to reach every part 

 of a small tree, a large tree, particularly one with rough Isark, it is almost impossible to 

 cover with the spray. 



THE GREEDY OR WHITE PEAR SCALE. 



Aspidiotus Rapax. (Comstock.) 



This species (Figure No. 3) aff'ects many kinds of trees, deciduous as 

 well as evergreens. It is easily confounded with a' closely allied species, 

 Aspidiotus convexus. This was probably imported. 



Description. — Scale, about one sixteenth of an inch in length; 

 form, ovoid; color, drab; larva, less than one hundredth of an inch 

 in length; two antennae, six-jointed; two anal setae. Female, bright 

 yellow. Male, winged. This insect is found in many places along 

 the coast. It infests, chiefly, pear trees, hence its name. It is dis- 

 tinguishable easily from the Aspidiotus perniciosus by its whitish-yel- 

 low color, contrasting with the dark color of the latter. And another 

 point of difference: the white pear scale leaves no special mark 

 where it has been, while the Aspidiotus perniciosus almost invariably 

 is followed by red marks. 



Generally, this scale has only one brood in the season, but I have 

 found them breeding on pears in the storehouse during the winter. 

 As compared with the pernicious scale, it is of little danger, owing 

 iiigureNo. 3. to its slow breeding propensities. 



Aspidiotus convexus resembles this form closely in habit and outward 

 appearance. It is slightly more convex, and is best distinguished by 

 microscopic characters. 



