494. QUEENSLAND AGRICULTURAL JOURNAL. [1 June, 1898. 
Entomology. 
PERNICIOUS OR SAN JOS! SCALE. 
(ASPIDIOTUS PERNICIOSUS, Comstock.) 
By HENRY TRYON, Entomologist. 
Prates (XL. and XLI.) 
[INTRODUCTORY .] 
Durie the years 1894, 1895, 1896, and 1897, when either no legal restric- 
tions existed or were put into operation with regard to the importation of 
plants, this insect was repeatedly introduced into the colony and widely 
disseminated therein on nursery stock supplied by two Sydney firms. As also 
the right of inspecting orchards was not secured, and the treatment of such 
as were diseased was not rendered imperative by law, it has already become 
established by this means in orchards and gardens in several parts of 
Queensland, including the districts of Stanthorpe, Warwick, Allora, Brisbane, 
Emerald, North Coast Railway line, Maryborough, Rockhampton, &¢.—in 
all of which localities specimens have been found by Mr. A. H. Benson, 
Fruit Expert, and the officers associated with him, by different resident horti- 
culturists, or by the writer himself, by whom also the identification in each 
case has, moreover, been quite definitely established. And ‘‘That the San José 
Scale was introduced into Sydney from California by a nursery firm some four 
or five years ago upon apple or pear stocks, there cannot be the least doubt; for 
[and] in every instance where it has been ‘discovered the trees from which the 
infection spread have come from the same place.’ (W. W. Froggatt, I., p. 875.) 
It was first noticed in the district of St. José, California, as an orchard 
pest in 1873, and locally known there as the “Small Round Black Seale.” 
Being from the first a destructive insect, and manifesting a tendency to spread, 
its reputation soon extended to other districts, where it was referred to as the 
St. José (Host) Scale: In 1880 it was’ technically described by Professor 
Comstock in his elaborate paper on scale insects, contained in the Report of 
the United States Entomologist for that year; the name Aspidiotus perniciosus 
or Pernicious Scale being assigned to it, because in his opinion “it was the 
most pernicious scale insect known” in the United States (L., p. 304). 
Since its first discovery in California it has become widely disseminated, 
occurring now in many States to the east of the Rocky Mountains, in British 
Columbia, Chili, Kauai (Koebele), Australia. 
In Japan it is represented by two scale insects—named, respectively, 
Aspidiotus albopunctatus and A. andromelas—that do not differ from it by any 
marked structural characters (Cockerell, XIIT.). 
Various countries (li. O. Howard, VIII., p. 290-1) have been suggested 
as its original home, whence it has been transported into regions where it ig 
now found to exist; amongst the number being Chili, the Western United 
States of America, the Pacific Islands, Australia, Eastern Asia, and Japan. 
W. M. Maskell and T. D. A. Cockerell have independently, and on different 
grounds, concluded that it is indigenous to the last-named country; and 
although there are some difficulties in accepting this country as its source, the 
origin of Aspidiotus perniciosus therein seems probable. The matter of its 
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