35 



their beaks into the bark, begin to suck the sap from the tree. 

 About this time little waxy threads develop on the surface of the 

 body, and soon fuse together to form the fir^t portion of the cov- 

 ering scale. When this is completed the scale is white, nearly 

 circular in outline, and with a little hump or nipple iu the centre. 

 About ten days later the insect molts its outer shell and adds this 

 to the covering scale, which by this time has become dark gray, 

 except the central nipple, which is lighter colored, often yellow. 

 About ten days later the female insect molts again, and, as before, 

 adds the molted skin to the covering scale, thus making it larger 

 than those of the males, which do not undergo a second molt. • 



Soon after molting the second time the females become mature 

 and begin to produce young, " averaging ten a day for more than 

 a month." Each of these young develops as just described for 

 the parent, and those produced first have begun to produce young 

 in their turn before their parent has completed the same process. 



As a result, young, crawling forms may be found at almost all 

 times from the last of June until frosts appear in the fall, during 

 which time it has been calculated that the progeny of a single 

 female may number 1,608,040,200, all of which have obtained 

 their nourishment from the plant they are on. With a power of 

 increase as rapid as this, it is not strange that trees suffer severely 

 and often die in a short time after being attacked by this pest. 



Food Plants. 

 The San Jos6 scale feeds upon nearly all our plants, shrubs and 

 trees, except evergreens. Its more usual food plants, however, 

 appear to be the pear, peach, plum, cherry, strawberry, raspberry, 

 blackberry, gooseberry, currant, grape, rose, osage orange, elm, 

 maple, chestnut, oak, birch, willow and Japanese plants. It 

 attacks trunk, branches, twigs, leaves, and even the fruit ; and 

 during the year 1900, currants, pears and apples, grown iu Massa- 

 chusetts, were received so covered by these insects as to render 

 them unsalable. 



Distribution in Massachusetts. 

 This scale was first discovered in Massachusetts in 1895. Since 

 that time it has appeared in a large number of places in the State, 

 probably introduced on stock purchased from infested nurseries, 

 and it is now known to occur in the following places : Amherst, 

 Arlington, Attleborough Falls, Auburndale, Bedford, Belcher- 

 town, Belmont, Beverly, Billerica, Boston, Brighton, Brockton, 

 Brookliue, Canibrid<j;e, Canibri(lgei)ort, Concord, Danvers, Digh- 

 lon, Dracut, East Taunton, Everett, Fairfield, Fitchburg, Frani- 



