FUNGOUS AND OTHER DISEASES. 69 
It is evident, from the records of true parasites given at the outset, 
that native parasites are beginning more and more to attack the San 
Jose scale. The native predaceous beetles will follow suit, and un- 
doubtedly as years go on the seriousness of San Jose scale infestation 
will diminish, as, in fact, it has already done in California and perhaps 
noticeably also already in some sections in the East. 
FUNGOUS AND OTHER DISEASES OF THE SAN JOSE SCALE. 
Scale insects are more or less subject to control by fungous and 
other diseases, and the San Jose species is no exception to this rule. 
Control by these agencies is particularly efficient in the moist Tropics, 
so much so that most scale insects are practical^ wanting in such 
regions. The armored scales, such as the San Jose scale, are rarely to 
be met with in tropical regions in any numbers, and where found are 
diseased in a large percentage of cases. The mealy bugs, however, 
are comparatively immune. The efficiency of these diseases as a means 
of control lessens as one leaves the Tropics, but in the subtropical 
regions of the United States, and even in the temperate regions, the San 
Jose scale has in man}^ instances been very general^ exterminated by 
disease. Several of these diseases are obscure and have never been 
scientifically studied, nor have they developed any fruiting stage so 
that they could be studied with any degree of accuracy. 
In the early work with the San Jose scale in California, Mr. Coquillett 
reports the death of the San Jose scale from an unaccountable cause, 
supposedly disease, in Pasadena County, Cal., on pear trees which 
had not been treated with any kind of insecticide. Specimens of 
twigs covered with dead scales were submitted to the Bureau of 
Plant Industry for examination. No specific disease germ could be 
discovered, but this does not preclude the explanation of some definite 
disease as the cause of the death of the scales. Similar cases have 
come up in the East several times, the first perhaps occurring at River- 
side, Md., in the early history of the scale, where, without treatment, 
the scale died in a very large percentage thruout a considerable orchard. 
A number of similar cases were reported b} 7 Doctor Howard in Bul- 
letin 12, one from Tifton, Ga., where a careful count of the scales 
showed that on one twig out of 183 scales 4 were living; on a second, 
out of 723 scales 2 were living, and on a third, out of 579 scales 28 
were living, giving 34 living scales out of 1,485, a mortality rate of 
97.7 per cent. A similar case was reported also from Wadley, Ga. , 
by Professor Starnes, and Professor Alwood has noted the same con- 
ditions at Vienna, Va. Doctor Howard also records the fungus- 
infested scale reported by Doctor Fletcher at Fruitland, Ontario, altho 
here the fungus or disease is probably a different one. 
A more promising and important disease of the San Jose scale is 
the cosmopolitan scale-insect parasitic fungus Sphaerostilba coccophila, 
