Sept. 1, 1899.] 
THE TROPICAL 
AGRICULTURIST. 
To the Editor: 
MOROWAK KORALE TEA PEST. 
July 27. 
Sir,— The caterpillar alluded to as having 
done damage on Silvakande is most probably 
Thosea Recta. If the Superintendent will 
examine his bushes, he will probably ilnd 
that a certain number of the caterpillars 
are spinning their cocoons. If he places a 
few cocoons in a box, he will (after they hatch 
out) be able to identify the moth, or butter- 
fly. This is small and insignificant, but, if 
observed in large mmibers^ a look-out should 
be kept in the spots where they are seen ; 
and the trees (on which the eggs are laid) 
pruned down, and the prunings burnt heforcthe 
caterpillar hatches out. Prevention is better 
than cure, which is difficult. As the cater- 
pillars can only crawl, a cordon of quicklhue 
is about the best thing to stop their advance 
with. Carbolic spray and disinfectants ap- 
pear to be of very little use. When the cater- 
pillars begin to spin up their cocoons the 
affected bushes should be pruned and all 
prunings burnt. 
The writer has seen two severe attacks in 
1885 and 1897, on different estates at 1,500 odd 
feet elevation. In neither case was there 
any repetition of the attack in the following 
year. Neighbouring estates (rather than the 
one attacked) should be on their guard. 
Mr. Frank Mackwood could probably tell a 
o-ood deal more than the writer about this 
pest. -Yours, &c., THOSEA RECTA. 
THE TEA PEST AT MORAWAK KOl^ALE. 
Pati Kaja Estate, Elpitiya, July 23. 
Sir,— Is it not possible that tlie tea pest now 
reported to have done such damage in the Mora- 
wak Korale is the blue striped nettle gi ub 
(Parasa lepida) described on page 66 of a little 
hook by E E Green, called "Insect Pests of 
the Tea Plant," published by the "Independent" 
press iu 1890. Mr. Green mentions that Nietner 
included the pest under the name of Liconiodes 
graciosa, in his " Enemies of the Coffee Tree." 
Will you kindly look up Mr. Green's article on 
this pest and reprint it if you think the descrip- 
tion applies.— I am, etc., 
GEO. THORNTON PETT. 
THE BLUE-STRIPED NETTLE GRUB {Parasa lepida.) 
There is a family of caterpillar (the Lima colidfe) 
many species of which are armed with stingins; hairs, 
aod which for this reason may appropriately be 
called ' nettle grubs.' There are several kinds that 
feed upon the tea plant, the most conspicuous amongst 
them being the larva; of the Parasa lepida. They 
are gregarious and are sometimes present in such 
large numbers as to completely defoliate the trees 
upon which they are feeding. A neighbour who sent 
iQe specimens told me that more than fifty of them 
had been removed from two adjacent tea bushes, 
in another instance a group of four or .five 
trees were left quite bare, and the superintend- 
ent, seaching for the cause of the mischief, received 
practical demonstration of the stinging properties of 
the caterpillars. 
The same species is frequently found on coffee and 
occasionally upon cinchona trees. Mr, Nistuer in- 
cluded it, under the name of Licoviodes graciosa 
in hia catalogue of " Enemies of the Coffee Tree." 
Upon the first occasion that I saw a cooly. stung 
by this caterpillar, I had the curiosity to experinient 
with it upon myself. I touched it lightly with -the 
back of my hand and immediately felt a sharp sting- 
ing .sensation similar in kind to, but rather morein- 
tense than, that produced by the common stinging 
nettle. Small white Ir.mps- were ■ raised where the 
poison had penetrated the skin. The pain though 
severe at first ilid not ip.st very long. • ' • - 
The egg^s are genfrally attached to the under surface 
of tlie leaves. Their form and colour make them very 
difficult to see. From fifteen to twenty are laid to- 
gether f lossly overlapping each other like the ■scales 
of a fish, which they resemble also in their fiattened 
oval, shape. They are almost transparent; the dull- 
yellow riug-shaped embryo can be' seen through the 
shfll. 
The full grown larva is of a brilliant yellow green 
colour, with a rich lilac stripe along the middle of, the 
back, and a bright blue stripe ou each side, each 
stripe bordered by a darker line of the same tint. The 
poisonous spines are arranged in tufts along the body: 
they ,are pale green, tour tufts near the head and 
another pair near the tail tipped with scarlet : there 
are four large black spots at the hinder end of^ the 
body. 
Specimens of this Jcind of caterpillar that ha ve heen 
feeding upon tea are much, more hrightly coloured than 
those tliat have heen reared u./)on cojf'ee lea ves. The latter 
are cirnamented with green stripes and shines Upon a 
pale greenish white ground, tiiey might easily be 
mistaken for a distmct species. Another peculiarity 
of these caterpillars is the rudimentary condi>ion of 
their legs. Their movements are more lilce those of slugs 
and snuils tha'ii of ordinary eraiuling insects. The 
cocoon of the ' nettle-grub ' is hemispherical, of a 
daik brown colour, closely resembling the tea stems 
upon which it is usually placed. It is thin but very 
compact, formed of silk strengthened with a tough 
cement secreted by the insect. 
The Uioth escapes from the cocoon by a lid-like 
opening at one end. It is a gaily coloured insect ; its 
front wings are chocolate-brown with a broad emerald- 
green band stretching obliquely across them, tha hind 
v/ings buff, tinged with chocolate at the margins ; 
front and side of the thorax emerald-green, and a 
small spot of the same colour at the base of the two 
front legs. 
As in the case of most of the le.if- feeding cater- 
pillars, the injury to the tree is only temporary. The 
grubs when found should be removed and destroyed, 
but, under the . circumstances, some other method 
than ' hand picking ' will be found advisable. <; 
July 29. 
DE.A.R Sir, — The ,Superintendent of the estate 
attacked is apparently satisfied that it is, the 
' nettle-grub ' described by Mr. E Green, and so- 
called on account of its painful stingina' capabili- 
ties. The term 'f^rub,' by the way, is rather- 
misleadinf;, a.^ it is usually applied to caterpillars 
which live underground. The ' nettle grub,' which 
is occasionally found feeding on cacao tiees, and 
is apparently slowiy increasing on that proilucfc, 
may easily be identified by its excreta which are 
cup-shaped. If the Superintendent of Silvakande 
is right, his simplest remedy is to prune every 
branch of tea, or other vegetation, on which 
either the caterpillars or cocoons can be found, 
and burn them before the moths emerge from 
their cocoons and a new brood developes. The 
caterpillars when disturbed cling very tightly to 
the leaves instead of dropping, as many species do, 
to the ground. 
There must be something wrong in the condition 
of the aifected tea fields to predispose them to 
such wholesale devastation as has been described, 
and the forldng of the soil and the application 
of lime and wood aslies would probably be of great 
