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mites in rubber nurseries. 
My attention has lately been attracted to several cases where 
the seedlings of the “ Para ” rubber tree presented a somewhat 
unhealthy appearance, and on more than one occasion I have 
been assured’that this was there natural appearance during, or 
immediately after, a spell of dry weather. It is evident, however, 
that all is not as it should be, and if the growing point or the 
very young leaves are closely examined, a minute insect will 
generally be observed moving rapidly about, chiefly on the under 
side of the leaf. 
This is not a true insect, but one of the Mites {Acarincc) 
and allied to the pests that infest and produce the galls and leaf 
blister on plants. One of the best known of these Mites is that 
commonly referred to as “Red Spider” ( Tetranychus telariu 
which is very common in hot houses in Europe, being especially 
abundant on various species of Acalypha plants of the same 
order as the “ Para ” rubber tree; other Mites are parasitic on 
animals, while the itching Mite is parasitic on man, causing 
the disease known as itch; the sensation which gives the name 
to the disease being due to the Mites burrowing in the skin. 
In the particular case under note, the very young leaves fall 
from the plant before they are developed — in this respect the result 
is much the same as though the plants had been attacked by 
“ Red Spider ” — while those leaves which mature, present a 
crinkled appearance and are generally of a yellowish green colour, 
and will be found upon examination to be perforated b) 7 numerous 
boles, due to the punctures of the Mites when the leaves were 
young. Saprophytic fungi are also present, but the disease is 
primarily due to the depredations of these minute parasites. 
Being so small, these Mites are apt to be overlooked, and the 
cause of the disease attributed to other causes; they can be 
detected by the paked eye by anyone possessed with keen 
eyesight, though a good lens or a microscope is indispensable 
to enable us to obtain a correct idea of their structure. 
The particular Mite causing the disease alluded to above, is 
probably a species of Tarsonymus, but I am unable, with the 
literature at my disposal, to determine the species. This, however, 
is not of much consequence to the planter, as the cause and 
effect is much the same in the various members of this family. 
Mites are produced from eggs, and-, as a rule, the young are 
provided with three pairs of legs: they thrive best in a warm dry 
atmosphere. When they occur on plants having smooth leaves, 
they can be kept in check by syringing with clean water, or with 
a solution of soft soap and quassia chips. Dusting the affected 
parts with tobacco dust will also be found very effective and 
perhaps more expedient : this should be done in the evening so as 
to reduce the risk of it being blown off, or washed off by heavy 
rain. 
2 
bjloi 
