372 
THE TROPICAL AGRICULTURIST. [Dec. 1, 1900. 
(ind burns the pruninga, which is certainly the best 
thing to be done under the circumstances. But a large 
proportion of the insects is sure ts escape, and a fourth 
or even fifth extensive plague of the citerpillars may 
appeir at regular intervals. But a period is sure to 
arrive — varying usually from the third to the filth 
brood— when the p-st appears to reach its climax and 
to disappear as suddenly as it came, giving no further 
trouble perhaps for several years. This relief may be 
brought about by several circumstances. The natural 
enemies of the caterpillar (Ichneumon wasps and 
Taohinid flies) discover the plentiful sapply of food 
and incriinse proportionately until they obtain the 
upper hand once more. A peculiar epidemic, allied to 
or identical with the disease that is sometimes so des- 
tructive to silkworms, often kills them wholesale, and 
is usually the pnncipal agent in reducing the pest. 
This disease appears to be very infectious. Caterpillars 
killed by it become rotteu and have a very ofiensive 
smell. The spores of the disease are distributed over 
the leaves of the plant and are eaten by the other 
caterpillars, which die in their turn, Fortunately the 
disease does not — as far as we know — affect the higher 
animals, but the process of tea manufacture would in 
any case purify the leaf. Weather is also probably an 
important factor in the rise and fall of these caterpillar 
pests. Though it may not directly affect the caterpillar 
' itself it may have a very appreciable effect upon the 
enemies of the caterpillar. Thus, the damp warm at- 
mosphere following copious showers of rain is particu- 
larly favourable to the growth and spread of the 
fungal epidemic mentioned above. 
Remedial Measures. 
In the case of leaf-feeding caterpillars considerable 
success has been obtained in other countries by spray- 
ing with mineral (usually arsenical) poisons. The 
Americans have paid great attention to these prepa- 
rations, such as arsenate of lead and '' green arsenoid," 
and are manufacturing them at rates that permit of 
their being freely employed. I have hitherto never 
recommended the use of mineral poisons for spraying 
tea plants, fearing the (possibly very remote) danger 
of the mineral accumulating in portions of the manu- 
factured tea in poisonous quantities. But I now con- 
sider that all risk might be obviated by a simple 
precaution, namely, to stop plucking for a sufficient 
time after the application — 10 days would be enough 
— to make sure that the plucked leaf shall have 
developed since the date of the application. Spriy- 
ing could therefore be done immediately after a field 
had been plucked. The actual leaves that will be 
taken at the next round will be still in bud at the 
time of this application, and will unfold in the 
usual interval. These leaves will be quite free from 
any trace of the poison. 
The most convenient form of sprayer is the knapsack 
type, which can be easily worked by one man with 
a second man to feed it. If arsenate of lead is to 
be employed as a spraying mixture, it may be 
used at the rate of i lb. to 100 gallons of water. 
The poison should be first made into a thin paste, 
and the rest of the water added subsequently. The 
addition of powdered lime (in equal weight to amount 
of the arsenate) is gsid to prevent any injury to 
delicate foliage. 
Moth traps of the following description will often 
destroy a large number of the winged insects. A 
small coconut oil lamp is placed in the middle 
of a large tin tray or basin containing water with 
a film of kerosine floating on the top. The moths 
are attracted by the light and fall into the water, 
where they are killed by the film of oil. This trap 
will be of use only when the moths are on the wing. 
It will be found more efliective on dark still nights, 
and should be placed well away from any counter 
attraction in the shape of bungalow lights. It will 
he useless during moonlight, it being a well-established 
fact that few moths are on the wing at such 
times. 
But the good old rule that " Prevention is better 
than cure" is particularly applicable in the treat- 
ment of insect pests. As has been shown above, 
plafjues of caterpillars are sul ject to more or less 
regular fluctuation, increasing until a certain climax 
has been reached, and then psacticiilly distippear- 
ing for a term. This disappearance is not coii.piete. 
There must always be a fcW imiividuals Ciinying 
on the breed ; their increase checked fur a time by 
causes that are oul.v partly understood, such as climatic 
conditions, natural enemies, aud parasitic diseases, 
&c. It should be our aim to a^oiot these natural 
checks by keeping a look-out for Mnd de^jtroying any 
caterpillars that may be seen duiiag wh;it wc may 
call the "off season." Tiie plu kert should be ius- 
tructed to always remove and ciij=h ai.y twisied cr 
folded leaves observed on the trees, and if any of 
the larger species of caterpillars aie seen the tree 
should be marked and the fact reported to the 
superintendent, who should must carefully search 
that and the immediately surrounding trees and 
destroy every individual caterpillar found there. With 
plucking continued throughout the year, every single 
tea bush must pass under the hands of a cooly at 
intervals of about ten days, and if this system of 
observation is properly carried out it would seem 
almost impossible for any caterpillar pest of the 
tea plant to get out of hand. I cannot lay too 
much stress upon the importance of great atteotion 
throughout this off season or resting period, when 
the tea seems to be most free from attack. It is 
at such times that the planter is apt to be off his 
guard. 
When caterpillars have to be collected by hand, 
they may be conveniently destroyed by placing them 
in a mixture of phenyle and water (1 to 20). 
The following species have at different times coma 
under" observation as serious caterpillar pests . — 
*1. The "Pale Tea Tortrix," Capua menciana 
Wlk. 
*'2. The "Variegated Tea Tortrix," Capua fun- 
determined species). 
3. The "Leaf 'RoWor," Gracilaria theivora,\J[am, 
4. The '' Blue-striped Nettle grub," Parasa leqida, 
Cram. 
5. The " Morowak korale Nettle grub," Thosea 
recta, Hampson. 
6. The •' Green Nettle-grub," Thosea cana Wlk. 
7. The "Fringed Nettle-grub," Hataia nararia, 
Moore. 
8. The " Red Slug," Eeterusia cinqala, Moore. 
9. The " Small Bagworm," Manatha alhiqes, 
Moore. 
10. The " Large Bagworm," Clania variegata, 
Snell. 
11. The " Twig Caterpillar," Boarmia hkunnitra, 
Wlk. 
No, 1.— The Pale Tea Toetrix," Capua menciana, 
Wik. 
Eggs : not known. They are probably concealed 
at the base of the buds of the plant. 
Caterpillar : dull green or greenish white, with 
a shining black head and a black horny patch on 
the back of the second segment. There are about 
12 minute tubercles on each division of the body, 
from each of which springs a flue bristle. When 
full-grown the caterpillar is about | inch long. 
The larval stage occupies about a fortnight, after 
which the caterpillar fastens two leavjs fiimly to- 
gether and turns to a dark mah jgany-coloured 
chrysalis. 
* Since the above was written find set np in pi int, 
specimens of Tea Tortrix have been kiud'y exaniiced 
by Mr. J. Hartley Durrant, F.B S , who lepurts that 
the supposed new species is not really distinct from 
No. 1: and that both these species should be re- 
ferred to an earlier name, — Capua coffearia Nietner. 
