374 STATE HORTICULTURAL SOCIETY 



THE SAN JOSE SCALE. 

 Aspidiofus pernicloxus Comst. 



At i^resent this is the most important of all the species of insects 

 which attack nursery stock. It is most important, not only because of the 

 injury to the trees which it is capable of doing, but because nursery men 

 and fruit growers are afraid of it and hence hesitate to buy stock from 

 a nursery in a locality where the scale is known to exist. It is also of 

 especial interest to nursery men and fruit growers in this state because 

 it is being found each season in new localities within our borders. The 

 fmding of the scale in a small nursery near Union Springs probably 

 means that it has been sent to numerous localities within the state. 

 Much has been written about it and it has been described and its life his- 

 tory written over and over again. Yet a very large majority of the 

 nurserymen and fruit growers of the state seem to have but little idea 

 of the true nature of the insect. It may be well, therefore, to give a 

 somewhat detailed account of it in these pages. 



ITistory. — The original home of the San Jos^ scale is not positively 

 known. Some writers think that it originally came from South America, 

 while others believe that its native home may have been Japan or pos- 

 sibly Australia. But wherever its original home may have been it is 

 said to have been known in the San Jos6 Valley, California, as early 

 as 1870, In 1880 Prof. J. H. Comstock described it and gave it its scien- 

 tific name. It was not discovered in the east until 1893, when a few trees 

 in an orchard at Charlottesville, Va., were found infested. Subsequent 

 investigations showed that these trees came originally from a New 

 Jersey nursery. In 1891 the scale was found on Long Island and other 

 points in this state. 



Present distribution. — According to JNIessrs. Howard and Marlatt* the 

 scale was known in 1896 in Alabama, Arizona, California, Delaware, 

 Florida, Georgia, Idaho, Indiana, Louisiana, Massachusetts, Maryland, 

 New Jersey, New York, New Mexico, Ohio, Oregon, Pennsylvania, Vir- 

 ginia, Washington, West Virginia and British Columbia. In addition 

 to the above' states it is now known to occur in several localities in Michi- 

 gan and in the provinces of Canada. In this state it has been found in 

 the following counties: Suffolk, in several orchards; Queens, in three 

 nurseries; Kings, in one small orchard near Brooklyn; Orange, in an 

 orchard at New Milford (Dr. Lintner); Dutchess, in an orchard near 

 Poughkeepsie; Columbia, in an orchard near Germantown and two at 

 Kinderhook; Tompkins, on ornamentals on the campus of Cornell Uni- 

 versity; Seneca, two trees, which have been burned, in an orchard near 

 Farmer; Cayuga, in an old nursery near Union Springs. 



Food plants. — The following list of food plants, which includes those 

 observed up to 1896, is given by Dr. J. B. Smith. f It will be of especial 

 interest to nurserymen and hence is given here in full. Linden, euony- 

 mus, almond, peach, apricot, plum, cherry, locust, spiraea, raspberry, 

 blackberry, rose, hawthorne, cotoneaster, pear, apple, quince, flowering 

 quince, gooseberry, currant, flowering currant, persimmon, acacia, elm, 

 osage orange, English walnut, pecan, hickory, alder, chestnut, oak, birch, 



*U. S. Dept. Agr. Div. Ent. Bui. 3, new series. 

 + N. J. Agl. Exp. Stas. Rept. 1896, p. 547. 



