58 THE SAN JOSE OR CHINESE SCALE. 
slow where trees are moderately widely separated, and usually an 
entire orchard will not become affected from a single original point 
for several years. 
Occasionally the young scales may be locally transported by men or 
teams. An interesting case in point is given by Professor Rolfs. He 
states that some melons growing in an infested orchard were given by 
the owner to a friend, who took them away from the orchard in his 
wagon. A year later the scale developed on a tree under which the 
team had been hitched while the melons were unloaded. As this 
orchard was entirely free from the scale originally, it seems to be a 
reasonable inference that the young had crawled upon the wagon, 
harness, or melons, were conve}^ed a distance of 3 miles, and suc- 
ceeded in gaining access to a tree which probably touched the wagon 
or team during the interval of unloading. 
PARASITES AND OTHER NATURAL ENEMIES. 
The following paragraphs, under the heading u True parasites," 
were prepared for this bulletin b}^ Dr. L. O. Howard. 
TRUE PARASITES. 
Some eight species of true parasites have been reared from the San 
Jose scale in this country. -Nearly all of these are widespread, occur- 
ring on the Pacific coast, and generally also in the East, and are found 
also in other parts of the world. None of them are specific enemies 
of the San Jose scale in the sense that they are limited to this species 
of scale, but all of them are general parasites on other armored scale 
insects. They are as follows: 
Aphelinus fuscipennis Ho wa rd . 
Aphelinus m/ytilaspidis Le Baron. 
Aspidiotiphagus citrinus Howard. 
Anaphes gracilis Howard. 
Physcus varicomis Howard. 
Prospahii aurantii Howard. 
Ablerus clisiocampx Ash mead. 
Rhopoideus citrinus Howard. 
Of these Aspidiotvphagus citrinus, Prospalta aurantii, Aphelinus 
fuscipennis, and Aphelinus mytilaspidis are of very wide distribution. 
Aspidiotiphagus citrinus, for example, originally described from Cali- 
fornia in 1891, is now found in many other portions of the United 
States, in the West Indies, Italy, Austria, Ceylon. China, Formosa. 
Japan, Cape Colony, Queensland. South Australia, and Hawaii, and 
this remarkable distribution is practically followed by the other three. 
The most important of these parasites is the little Aphelinus fusci- 
pennis. It was reared in large numbers by Mr. Coquillett, in Califor- 
nia, many years ago, where it was found to breed thruout the year, 
