ISG 



I'^Mcli ffiualc of till' (iver-wiuteriiiK y;cin"niti()ii is raijalilf. uikUt favouiMble 

 coiHlitioiis, of proaufins; aiiproxiniately one Inuulred youiig. In the course of 

 but one month these reach maturity and the females begin to iiroilvioe 

 another generation. There are thus pnxhieed some four or five generations 

 during tlie entire season. Under supposedly favourable conditions, shigle 

 females of the later generations have been observed to produce approximately 

 ()00 .young. Basing their estimates upon breeding-cage observations. Dr. 

 Howard and Mr. Pergande have sliown that it would be possible, under the 

 most favour.'ible conditions, for the jirogeuy of a single female to reach the 

 astonishing number of .•5,21(i.().S0.4(l(( individuals in a single season. Should 

 each of these scales reach the largest size, one-tenth of an inch, aud were they 

 all placed side by side touching each other in all directions, there would be 

 enough of them to cover, approximatel.y, five acres of surface. It is almost 

 needless to add that in the intense struggle for existence of organism with 

 organism, and with climate conditions, such an astonishing rate of multipli- 

 cation is not even apin'oximated under natural conditions. Nevertheless. 

 wluMi one realises tlie eu<]rnious rapidity with which this pest multiplies, it 

 is no longer a surprise that enrrlvxs work in spraying fails to give satis- 

 factory results. A few females here and there, upon very small portions 

 of the tree which have not been reached by the siiray, may, during a snigle 

 seast)n, completely re-infest that tree. Satisfactory results are obtained only 

 by the most thorough worl;. Kvcry .s(piare inch of surface of trunk. limbs, 

 branches and twigs should be thoroughly covered, Ky far the most connuou 

 cause of unsatisfactory results is the failure of those who spray to do 

 thorough work. 



Ihiii- the Sim Jokc Scale Spridils. 

 Since the female scale is motionless, and permanently attached through- 

 out life to the branch on which it feeds, it is often asked how it is that tlie 

 i>au .lose Scale can spread from tree to tree, orchard to orchard, and even 

 for greater distances? It is only during the first few hours of its existence 

 that one of these little jiests can emigrate, and observation has shown that, 

 even then, it is incaiiable by its own efforts of getting more than a few feet at 

 most from the tree on which it was born. But birds and bees and other 

 insects make good air-ships for the little creatures, aud no doubt many a 

 ,voung scale has crawled upon the foot of a bird or upon some larger insect 

 and thereon voyaged lo tlie distant realm of another tree or orchard. No 

 doubt, also, strong gusts of wind often tear them loose from the liark lui 

 whicli they are crawling and waft them to the lu'aiiclies of neighboring 

 trees. These are provisions of nature for distributing the species. Tlirough 

 the cli.-muels of trade they are carried long distances, even from continent 

 to continent, upon Infested luirsery stock, cuttings, etc.. aud iiroliably to. a 

 lesser extent upon infested fruit. Buds aud scions carelessly taken from .an 

 infested tree may transmit the pest to the orchard in which ilicy ai-e |il:icc<l, 

 or may infest an entire block of trees in some nursery, .ind thence be 

 distribtited to m.-uiy orch.irds. It is also probable that many are carried 

 about uiion the hands anil clothes of the men who prune the trees or jiick 

 the fruit (U' otherwise work :ilioul the orchards, — Oniniii lliillitiii .\,,. ss : 

 Ctinlh II. 



