90 
pale reddish brown beneath black largely spotted with dull yellow. 
The largest specimen was some inch and a half long. ” The group 
to which the caterpillar belonged is not stated, presumably it was 
that of a Noctuid moth. The caterpillars were found to be numerous 
on secondary jungle near the rubber fields. They were destroyed 
by spraying with Paris Green in water. 
H. N. R. 
REPORT ON DISEASED RUBBER TREES 
FORWARDED FROM PUAK. 
These saplings had the appearance of having been gnawed at by 
some insect pest, but a close microscopic examination failed to 
identify any such source of trouble. 
Thin sections of the stem and roots, when examined microscopi- 
cally, presented * appearance shown in sketch. 
Longitudinal Section. 
The bark cells have undergone disintegration, 
and in some cases the cambium layer has been 
eaten into. 
Whilst the removal of bark from young 
trees is in itself highly undesirable, anything 
tending to reduce the vitality of the cambium 
layer must be viewed with grave suspicion. 
Experiments were set in progress with the 
object of detecting any fungi associated with 
the diseased parts. Cultures were prepared by 
inoculation therefrom on prepared and sterlized 
potatoes and on Agar-Agar nutrient media. 
Within 24 hours vigorous growths appeared 
on the latter, and on the second day a similar 
activity was demonstrated on the potatoes. 
From these mixtures of fungi, the individual 
organisms were separated, and pure cultures 
prepared. In almost every case one sporiferous 
bacillus predominated. 
Every precaution was taken during inocula- 
tion to avoid contamination from without, but 
it must not be overlooked that any soil is copi- 
ously supplied with organisms, many beneficial, 
and a few harmful, and also that the organisms 
separated in the above experiments may have 
been the sequence to, rather than the initial 
cause of the trouble. 
It has been proved that the healthy rubber 
tree is self — protective against most insect pests, 
but no similar state of affairs has yet been 
shown to exist for fungi. 
