BAMBOOS: THEIR CULTURE AND USES 43 
the past five years its life history has been pretty thoroughly studied, 
and satisfactory methods of control have been worked out. For a 
number of years it was impossible to account for the presence of the 
creature at Brooksville and nowhere else in the county. Suspecting 
that it might occur on related plants, such as sugarcane, sorghum, 
and native grasses, these were carefully studied, but no evidence of 
the presence of the mite could be found. Attention was then turned 
to Ja]:>an, and within the last two j^ears the mite has been found on 
specimens received directly from several localities in that country. 
There can no longer be any doubt that the mite was introduced from 
Japan when plants were brought to this country in 1909 which soon 
thereafter were sent to Brooksville. 
The mite in various stages was submitted to Dr. Nathan Banks, 
of the Museum of Comparative Zoology, Cambridge, Mass., who 
decided it was a new species and named it Tarsonemus tamhusarium. 
The sheath mite, as the name indicates, is found the greater part 
of the year snugly ensconced in the tightly clasping sheaths which 
form the lower portion of the leaves. Taking hold of the leaves of 
any of the Phyllostachys bamboos, to which this mite is confined, 
and pulling them apart, it is found that they separate easily. As 
each leaf is separated there will appear at last the stalk of the 
terminal leaf. It is usually around this tender moist stalk that the 
mites are found in great numbers. The}?- are flattened, reddish, almost 
microscopic creatures admirably adapted in every way to the condi- 
tions under which they live. The mites easily succumb to a little 
dryness; hence they do not long survive when the bamboo branches 
dry up. They live by sucking the juices from the tender growing 
parts. This causes the forming branches and leaves to abort, with 
the result that growth is checked. 
When the ground is rich and the plants are growing strongly, the 
writer has never been able to find that the mite produces any measur- 
able efi'ect on growth. A good many experiments have been made in 
colonizing mites on the young growing plants under control condi- 
tions. Plants thus colonized grow as well as though no mites were 
present. Where growth is poor for any reason, such as drought or 
lack of proper cultivation, mites are likely to cause damage by pro- 
ducing many blind branchlets; that is, branchlets where the termi- 
nal buds are killed. For the greater part of the j^ear, 8 or 10 months 
at least, the mites are confined entirely to the leaf sheaths. Many 
searches have been made for mites during the summer, fall, and 
winter months, but in no instance have they been found outside of 
the leaf sheaths. The period of migration of the mites begins the 
latter part of April at Brooksville and continues through IMay and 
June. Fortunately, this period is not coordinated with the proper 
time for the best propagation of the plants by the rhizome method, 
as pointed out in discussing methods of propagation. The propa- 
gating period is February and early March. This is fortunate, as 
it makes it practicable to carry on propagation work when the mites 
are confined to the leaf sheaths. 
A good many experiments have been made in efforts to find simple 
and economical ways of ridding the plants of mites. The best 
results have been obtained from treatment with hot water. This 
method was developed at Brooksville by K. N. Jones and has been 
