The San Jose Scale

Last September the vvork of fighting the SaD José scale iu tbis stats began in earnest, and the work dune tbus far by Inspector V. P. Hedriok bas been snfflcient to demónstrate that thia ranch dreaded orchaid pest has already secured a firm foothold and that its extertninat.ion will require the concertad aotion of all whose interests it threatens. From what sonrce the soale came to be introduced into the United States there is considerable doubt, bat it was known to exist in California as early as 1870; in 20years it became well distribnted throughont the western 3tates, bat the eastern states are snpposed to have been uninfested unfcil about 1890, when two prominent New Jersey nurserties were unoonsciously responsible for its distribution into several of the easteru states. It was probably introduoed into Michigan in 1891, although no autheutioated oases were reported until the summer of 1896, when Dr. Barrows and Prof. Taft, of the agricnltural college, located it in several places. Since the work of inspection began uew cases ure gradaally presenting theiaselves, nntil now it has been found in 20 different localitiep of the state, two of these localities being the oities of Detroit and Ypsilanti. The work of the inspeotor thus far has been conflned largely to nnrseries, as from these nurseries the scale, if present, is most likely to be distributed. Seventy nurseries baTe been inspected already, of wbich tbree wtre found to be infested. From this on the attention of tbe inspector will be devoted to private orchards wberever tbere is a possibility that the soale exists. The soale was introdaced into Michigan from several New Jersey nurseries, and from one or two shipments from California, and it is very probable tbat its wide distribution may be traced to those nursaries in tbis state, where it now exists. That the soale was not authentioally reported before 1896 is undoutedly due to the unfanailiarity of Miohigan orchardists with this pest. as well as to the over-confidenoe on the part of orchardists that this state was free from this pest. Besidea, to one unacquainted with the insect and its habita, its presenoe would ordinarily be passed by unobserved until the infested trees themselves oreated a suspicion that all was not well. Thu scale will be fonnd encrusting the twigs and branches, giving them a longb sonrvy appearanoe. This soorvy material representa an infinite nnmberof the email circular scales nnder which are fonnd the inseots themselves. The scale varies in size from one-thirtieth to one-sixteeuth inch in diameter and may overlap eaoh other or even exist several layers deep ou the bark; they are gray colored and slightiy convex. Tbe insect itself varies in color from a yellow to a reddish orange. The rapidity with whioh this insect reproduces itself is remarkable. The females oommence to bring forth young in early spring and continue until the íroste of feil. In this locality it is possiblfl for four or five broods to be matured in a single season. It is estimated that one female during a season will bring forth from 200 to 500 female young These yonng insects develop in aboot one month, wheu they too, begin producing yonng, so it is possible for the progeny of a single female to reach s&veral millions in the one season. Only the larvae possess the power of locomotion and tbat for a compara tively short time. After the hirth o the young they move abont uutil they find a suitable place upon the bark wben they begin the work of extracting and assimilating the sap. Soou a waxy material is senreted, which hardens into a scale for the piotection of the insect and the insect spends the remainder o its life in oue spot nnless moved elsewhere by sorne outside power: Owing to this peculiarity the San José scale of itself is rather slow to beome distributed over large areae, but it is given assi6tanoe in this respect by various agencies. Birds are active agencies in its distrbutioo, as are also the wind aud various doinestic animáis that are allowed in the presence of infested treea. The damage resnlting frorn the scale is due to the extractiou of the sap from the tree or plant npon vvhich it feeds The insect passes the winter either as roatured insect npon the bark of th tiee with its proboscis firmly anohore in the soft vegetable tissues of the plant When spring opens and with it come the active operation of the circnlator; system the insect is then ready for it most nffeotual work. Vegetation suffei but little at fiist from the presence o the scale, but as its Dumbers iucreas and the diain continúes, the unhealtb condition manifests itself. Tbefoliag during a moderately dry season wi' turn yellow, while that of a health tree will remain prefeotly green. Or dinarily an orchard will survive abou three or four years after once infested Fortunately, in some sections of th country this insect has its euemies. I the west several parasites work upon i and in Florida a fnngns disease oper ates upon it with great havoo. So fa as is now known it has no ênemies i Michigan, and while the olimate is no most favorable f r the developnaent of f ungna diseases tliat wil! prey upon it, it is very probable tbat in time sorue parasite eneruies may present themselves. At present only two linea of treatment j are at disposal. One is the total destruotion of the trees infested, which is recommended in oase the trees are kirge or are badly infested. The orher metbod is in the nse of spraying sulntions. While it is almost impossible to eradicate the pest by this roeans, it is pcssible wirh small trees to hold it in oheok sotbat the damage done will be ight. The spray is nsed dnring the winter months, when the trees are deoid of foliage. Kerosene is used, bnt nly upoc the apple and the pear, as s use is destrnotive to all other fruit rees. Solution of wbale oil soap, two ooDds per gallon of water, is perhaps most largely nsed, aod strong potash waeh and liu.e, salt and sclphur have limitad nse. The soale seems to have little prefernce regarding the trees npon which it works. It is fonnd npon all of the cornruon frnit trees, and npon rnany of the orest trees. It, however, does not work upon one bearing trees. At Byon Center, in Ottawa oonnty, where be scale has been found in the most xaggerated form of any locality in this tare, tbe scale was found to have pread to the forest trees in the vicinity of the orchard. This fact seems of gieat significanoe, as if the soale onoe ecomes thorongbly esrablished in the orests of the state then all hopes of its final extermination will have passed nntil tbe forests themselves are desroyed. An act was passed by tbe last legisature to prevent the intraduotion and spread of the San José scale, and it is under the provisions of this act that the nspeotion is oarried on. Tbe law places the work of its execution in the lands of the state board of agricnltnre and provides for an inspector of uurseres and orchards. The tendency of the aw is to probibit toe importation of infestud stock into the state by reqniring that all stook shipped into Michigan be acoompanied by a certifícate showing that the same has been inspected by a state or government inspector and are free from tbe soale, to prevent the spread of the insect within the state by requiring all dealers in nnrsery stock and all agents to sell ander license. Ko dealer in norsery stock resident of a northern state is permitted to sell without a license. By these means it is intended to vigilantly guard all avenues by whioh the soale ruay be introdnced into the state, and with the co-operaiion of all parties concerned it is hoped to confine the scale to tbe limits in whioh it is now fouud, and, if possible, to gradually elimínate it from these districts.