ENTOMOLOGICAL SOCIETY OF ONTARIO. 87 



and forests, solely by one member of this republic, while the others are simply spectators 

 looking on with a disinterestedness that amounts almost, if not quite, to a total indiffer- 

 ence. These are the two at present, most important introductions of foreign insect pests, 

 but no one can for a moment suppose that others will not follow, coming as with the 

 San Jose scale, from we know not where. You, gentlemen, are engaged in a business 

 that necessitates the exchange of scions, grafts, trees and shrubs, but may also be dissem- 

 inators of these pests not alone to your customers, but to each other. And, whether you 

 will or no, you cannot escape being foremost in the settlement of a problem that half a 

 century ago was unthought of. Hence, while I address you on the subject of the San Jose* 

 scale, it will be to view it as a factor in what seem3 to me to be a great and difficult problem 

 in the future of your business ; and with this explanation I will proceed to consider that 

 factor. 



The San Jose' scale was first observed in this country in the locality in California from 

 which it derives its name, coming from we know not where, but probably from either 

 some of the islands of the Pacific or else some of the Asiatic countries bayond. This 

 introduction is thought to have taken place about the year 1870, and began to attract 

 the attention of fruit growers about three years later, but so far as known only in the 

 locality above indicated. In 1880 Prof. J. H. Comstock described the specieg, and 

 wrote as follows : " It is said to infest all the deciduous fruits grown in California, 

 excepting the peach, apricot, and black Tartarian cherry. It attacks the bark of the 

 limbs as well as the leaves and fruit. I have seen many plum and apple trees upon which 

 the fruit was so badly infe3ted that it was unmarketable. In other instances I have seen 

 the bark of all the small limbs completely covered by the scales. I think it is the most 

 pernicious scale insect known in this country." For the reason here given, Prof. Comstock 

 gave it the name of dspidiotus perniciosus, and I may here add that it has since been 

 found to occur on both the peach and apricot, and fully merits the name given it by the 

 describer. It appears to have spread quite rapidly, for in 1882, nine years later, it had 

 extended over all of the fruit growing regions of California and across Oregon into 

 Washington. As late as 1893, the Los Angeles Horticultural Commission, in their report 

 for that year, stated that the pest, if not speedily destroyed, would utterly ruin the 

 deciduous fruit interests of the Pacific coast ; that it not only checks the growth of the 

 trees, but covers them literally entirely, and the fruit nearly as much so, and, if left 

 unchecked, the tree is killed within three years' time. This will serve to show you the 

 serious nature of this little pest, as demonstrated by its twenty five years' residence on 

 the Pacific coast. 



I will occupy a few moments here to consider its probable origin, though, as before 

 stated, we do not as yet know the land of its nativity. It is found in Chili, but was 

 clearly introduced to that country from California. It also is found in Hawaian Islands, 

 having been introduced from California on prune and peach trees, and also in Australia. 

 But nowhere in these countries has it been found inhibiting indigenous vegetation, which 

 we entomologists claim, must be done in order to prove the nativity of the pest. Quite 

 recently, Professor Cook has sent it from California on the Loquat, Photinia japonica, 

 and, as will be observed, there are several of our forest trees included in Dr. Lintner's 

 list, but this proves nothing as it would be surprising if, in its twenty-five years' residence 

 in this country, it had not begun to adapt itsBlf to our native flora, precisely as some of 

 our native parasitic insects are beginning to learn that they can add it to their bill of fare. 

 Considerable of the nursery stock required in California is grown on some of the smaller 

 islands of the Pacific, as for instance, Tahiti, and it seems at least possible that we . may 

 in this way have acquired a pest that may be an inhabitant of an obscure island, and, for 

 aught we know, it may be so inconspicuous there as to require the trained eye of the 

 naturalist to detect it. 



The insect itself, Fig. 83, belongs to a group known as armored scale insects, their 

 nearest allies being the Oyster-shell Bark-louse, while still farther removed are the 

 Mealy-bugs. We have here in the east a somewhat similar sp9cies that I have found on 

 peach, plum, pear and maple. This is known as the Putnam scale, Aspidiotus ancylus, 



