THE SAN JOSE SCALE. 



(As)jidiotus perniciomtH Comstock.) 



A Serious and Recent Importation into JVfaryland. 



Bv Dr. C. V. Riley. 



PAST HISTORY OF THE SPECIES. 



The following history of the species np to the year 1892, may be re- 

 ])roduced from mv Annuiil Report as Entomologist of the Department of 

 Ao-ricnlture for 1893. 



l\\ the Annual Report of this Department for 1880, Prof. J. H. 

 Comstock described under the above name,, an insect which he had col- 

 lected iu Santa Clara County, Cal. He stated that from what he had 

 seen of the species, he considered it to be the most pernicious scale-insect 

 known in this country. He had never seen any other species so abundant 

 as this was in certain orchards, and was told that it infested all the de- 

 ciduous fruits grown iu California, except the peach, the apricot and 

 the black Tartarian cherry. As a remedy he suggested the use of strong 

 alkaline washes. 



Until verv recently the San Jose Scale has been confined to the Paci- 

 fic Coast, but 'has extended lun-th to Washington, and south to the Mexi- 

 can border, and has be- 

 come, perha])S, the chief 

 enemy to Pacific coasthor- 

 ticulture. Considerabk^ 

 attention has naturall\ 

 been paid to the species 

 . by California horticultu- 

 rists. 



In 1883, Matthew Cooke 

 published figures of the 

 larva, male pupa, and 

 adult male, together with 

 the adult female scales 

 on twig and fruit. He 

 stated that the insect was 

 first noticed by fruit ship- 

 pers as infesting fruit in 

 1873, at San Jose, Santa 

 Clara County. From that 

 time it spread rapidly un- 

 til 1880, and but "little 

 effort was made to ex- 

 terminate it. In the win- 

 ter of 1881-82, crude pe- 

 troleum was applied ex- 

 tensively; in some cases 

 CL. with good results, but in 



TIG. l.-San Jose scale: a, pear, moderately Infested- ^j^^ maiority of instances 

 natural size: 7), female scale— enlarjied. . , ^ 



-(trom Insect Life.) With great harm to the 



