EXPERIMENT STATION REPORT. 569 



make their way through the parent covering and on to twig and 

 foHage. From the thousands upon thousands of crawHng larvae 

 that swarm over all portion o*f the infested trees in early summer 

 only a small set of young scales is derived. These young may set 

 on either the leaves, or on the twig or new growth, and they have 

 none of the white appearance of the parent. They are, in fact, 

 little, oval, black or grayish scales somewhat like minute barnacles 

 and they arrange themselves when on a leaf, by preference along 

 the veins or ribs. 



The males, which are winged, come to maturity during the lat- 

 ter part of the summer or early fall. The females at that time are 

 apparently only half grown, nevertheless they are sexually ma- 

 ture and copulation takes place some time during September, 

 The males then die and only the females remain attached to the 

 tree. Those of them that may be attached to leaves make their 

 way to the twigs, or if they do not, they fall to the ground and 

 are lost. As a rule, however, it is the male scales that are found 

 on the leaves and the females that are found normally attached 

 to the twigs, so that no change of position is made necessary. 

 Soon after the trees are in full foliage in spring, the female scales 

 begin to increase in size. This increase in size seems meant to 

 provide material for the enormous quantity of eggs that are to be 

 produced. About the beginning of June the eggs are ready to be 

 laid, and then the first appearance of the cottony or, really waxy 

 mass, becomes obvious. The maximum size of these masses is 

 obtained about the middle of June and about this time the earliest 

 larvae begin to appear. Hatching continues, however, until well 

 along in July, and in fact, the beginning of July may be marked 

 as the period when the young are most active. From that time 

 on the cottony masses begin to look ragged, their function is com- 

 pleted and sooner or later wind and rain strip them from the trees, 

 carrying also the dead and dried bodies of the females that have 

 attempted to provide for future broods. 



Remedial Measures. 



Any attempt to deal with this insect is almost bound to result 

 imsatisfactorily. The texture of the scale is such that it is not 

 easily penetrated by insecticides that are safely used on foliage. 

 When the young appear they are protected by the body of the 

 female and by the waxy covering until they are ready to move 

 about and to set. At that stage of their existence they are. of 

 course, easily killed : but in order to kill off even a single brood. 



