33 



The young scales are very small, oval, yellow insects, with six 

 legs which they use in crawling about in search of a place upon 

 which to settle. It is probable that while they may move about 

 for four or five days before they locate permanently, in most cases 

 it is less than two daj's. 



Upon finding a satisfactory place on which to locate the young 

 insect inserts its beak in the plant and begins to suck its juices, 

 while fine waxy threads appear on the surface of the body and 

 soon unite to form the covering scale. This is circular in outline, 

 white in color and highest in the middle. About ten days later 

 the insect moults, and adds its moulted skin to this scale which 

 has now become darker, giving the entire scale thus formed a gray 

 color with a yellowish or whitish centre. Shortly after this, the 

 female insects moult again, adding the moulted skin to the scale 

 as before, and now soon become adult. 



Distributio7i. 



If while the young scale insects are crawling about a bird lights 

 on the tree, it is not unusual for one or more of them to crawl on 

 to its feet and thus be carried some distance when it flies, before 

 they can crawl off again at the bird's next resting place, thus estab- 

 lishing them in some other portion of the town or city. The larger 

 insects, also, aid in scattering these insects in this way, while 

 sudden gusts of wind maj^ carry the young from tree to tree in an 

 orchard. 



The most usual method of distribution, is by means of nursery 

 stock infested with this pest, each infested plant sent out becom- 

 ing a centre from which this insect spreads in all directions. 



Enemies. 



The chief foes of the San Jos6 scale are the lady-bugs or lad}'- 

 birds. These are small beetles nearly circular in outline and very 

 convex. One of the most important of these is the "Twice- 

 stabbed lady-bug," which is about an eighth of an inch long, shin- 

 ing black, with a small red spot on each side. A much smaller 

 black beetle, known as Pentilia misella, also feeds upon the scale. 



Recently a lady-bug very similar to the "Twice-stabbed lady- 

 bug" has been found in China, destroying the San Jos6 scale 

 there, and colonies of this insect have been brought to this country 

 by the United States Department of Agriculture in the hope that 

 it may be of equal value here. The results of this experiment 

 cannot now be determined as sullicient time has not yet elapsed. 



Several parasites are also known, but they have not thus far 

 shown their ability to control the scale, and a fungous disease 



