690 Bulletin 83. 



This year the egg stage lasted about a month, the eggs becom- 

 ing pinkish in color about a week before they hatched. Some of 

 the minute active scales emerged as early as June 23, but most of 

 them appeared about July i . The little creatures remained under the 

 protecting shell for several hours, some of them a day or more, 

 before venturing forth onto the branches. Thus if one of these 

 mother scales is overturned in the latter part of June, it may con- 

 tain hundreds of the active little creatures and as many more eggs 

 yet unhatched. 



The number of eggs laid by a single mother is enormous, reach- 

 ing into the thousands. We have not counted them under one of 

 these Plum Scales, but others have counted 1054 ^'^d 2200 under 

 similar scales of other species of Lecaniums. 



The young at last venture forth from under the shell, and 

 about July i may be seen actively crawling about on all parts of 

 the tree. The old mother shells which they have left contain 

 nothing but a whitish powder made up of minute egg-shells. 



Habits of the young scales in summer. — Soon after emerging 

 from the old shell of their mother, the little scales find their way 

 onto the leaves. Here they usually establish themselves close 

 beside the veins on the underside, some take up similar positions 

 on the upperside, while others attach themselves without regard 

 to the veins. In figure i is shown the young scales, natural size, 

 thus attached to the leaves. Although there are many more 

 scales on the leaf at the right, they are so nearly the color of the 

 underside of the leaf that they do not show as distinctly as those 

 on the leaf at the left. Practically all of the newly-hatched scales 

 thus established themselves on the leaves, or leaf and fruit 

 petioles, in July. The scales are then so small, scarcely .5 mm. 

 (.02 of an inch) in length, so flat and closely pressed to the leaf, 

 and so near the color of the undersides of the leaves that they 

 can hardly be distinguished without a lens. In some of the 

 worst infested orchards, nearly every leaf bore hundreds of these 

 little scales. With so many millions of little pumps at work on 

 a single tree sucking the sap, is it any wonder that many trees 

 made but little growth and that much of the fruit was dwarfed ? 



Through the kindness of Mr. C. M. Hooker, who sent us 

 infested leaves from time to time during the summer, w^ were 



