REPORT OF THE ENTOMOLOGIST AND BOTANIST. 



207 



Up to 1892, the San Jose Scale was thought to be confined in North America to 

 the Pacific States, where it has shown itself to be a most destructive enemy of the fruit 

 grower. It was probably first brought to California on fruit trees imported from Chili 

 about 1870, and the name, San Jose Scale, was given to it by fruit shippers in 1873, from 

 the name of the place in California where it was first noticed. It spread rapidly for 

 seven years without any particular attention being paid to it. In 1880, however, Prof. 

 Comstock pointed out the great loss which it was causing, and gave it the specific name 

 perniciosus, for the reason that he considered it to be the most pernicious scale insect 

 known in the country. It not only swarmed in countless numbers on fruit trees in cer- 

 tain orchards, but infested nearly all kinds of deciduous fruit trees grown in California. 

 In a special circular which Mr. Howard issued last year, when the insect appeared in 

 the States of Virginia and Maryland, he says as follows : " In the course of twelve 

 years, the insect spread through all the fruit-growing regions of California, through 

 Oregon and into the State of Washington." 



It is known as the worst insect pest of deciduous fruit trees on the Pacific coast, 

 and has caused great pecuniary loss. Many crops of fruit have been ruined, and thou- 

 sands of tre s have been ki led. (L. O. Howard, Circular No. 3.) 



In 1892 the insect was found in New Mexico on apple, pear, plum, pea-h, quince 

 and rose. It had been brought into New Mexico upon yoang trees rom California. 

 Nearly all the other instances of infestation east of the Rocky Mountains can be traced 

 to two nurseries in New Jersey, where the pest had been introduced in 1886 or 1887 

 on trees of the Japanese plum " Kelsey, " which had been procured from the San Jose 

 district in California. Idaho pear trees had also been frequently imported from Cali- 

 fornia, which were most probably infested. In 1891 and 1892 several blocks of young 

 apple trees were badly infested. It is on pear trees chiefly that this pernicious scale 

 has been distributed through the State of New Jersey. Prof. J. B. Smith says (Insect 

 Life, VII., p. 166,) : — "The Idaho pear has been the most dangerous because it came 

 infested whenever imported direct, and after it, came in close older, Madame von Sie- 

 bold, Garber, Lawson, Seckel, Lawrence and Bartlett. Other varieties are also in- 

 fested, but less frequently, and the scales do not do so well. Kieffers alone are absolute- 

 ly exempt, and closely following comes the Leconte, which is rarely infested in the 

 nursery, and never in the orchard, in my experience. One tree grafted with Lawson 

 and Kieffer had the Lawson branch and fruit covered with scales, while the Kietfer 

 branch was entirely free. Currants, black and red, became rapidly infested and the 

 scales were certainly distributed on these plants. " 



Mr. Howard says that this insect spreads 

 rapidly for a scale insect, and is the most 

 dangerous scale known. It is, too, incons- 

 picuous and would be overlooked by many. 

 Specimens of apple boughs received from Bri- 

 tish Columbia were entirely incrusted with 

 the scales, so as to give them the appearance of 

 r\ having been dusted with ashes. Mr. Howard 

 ^ gives the following description of the scale in 

 his circular above referred to : "The San Jose 

 Scale belongs to the same group of scale in- 

 sects, the Diaspinae or armoured scales, to 

 which the Oyster-shell Bark -louse of the Apple 

 belongs. It differs from this species, and in 

 fact from all other eastern species found on 

 deciduous fruit trees, in that the scale is per- 

 fectly round, or, at most, very slightly elon- 

 gated or irregular. (Fig. 11). It is flat, pressed 

 close to the bark, resembles the bark of the twigs 

 in colour, and when fully grown is between T *g 

 an 1 \ of an inch in diameter. At or near the 

 middle of each scale is a small, round, slightly 

 ^^^^^^^t^ir^^^ed black point; or ' this point may 

 same, still more enlarged. sometimes t ppear yellowish. When occur- 



