486 
THE TROPICAL AGRICULTURIST. [January i, 1890. 
were also attacked, especially Careya arborea, and even 
the tea plants of a garden which had lately been opened 
out in the neighbourhood of the forest. From some of 
the villagers Mr. Fisher also learnt that there had 
been similar attacks of catterpillars within their 
memory. 
The Insect, and its Life History. — The insect be- 
longs to the Bombyces moths of the family Liparidse 
and has been described* by Mr. Moore as Dasychira 
thwaitesii. 
The caterpillars, when full-fed, are about 1J to 2 
inches long, covered all over with long, erect, yellow 
hairs, a thick bunch of which occurs on the dorsal as- 
pect of each of the first four segments of the abdomen, 
and also on the terminal segment; there is a black trans 
verse stripe between the two anterior dorsal tufts. 
After it is full-fed the caterpillar spins itself up be- 
tween the leaves of its food -plant, into a scanty 
oocoon, composed of its own hairs, which appear to be 
very easily detached and whioh it binds together with 
silk. After almost completely denuding itself of hairs 
to form the cocoon in which it encloses itself, the cater 
pillar creeps out of its larval skin and becomes a pupa 
In the case of the February generation, which was the 
one that was kept under observation, the insect re- 
mained in the pupal state for further observation less 
than a fortnight. The most noticeable feature about the 
moth is the difference between the sexes, the male being 
very much smaller and more brightly coloured than the 
female. 
Mr. Moore describes the moth as follows : — 
" Male: fore wing, greyish white, crossed by a basa', 
antemedial. and a post medial, indistinct, black speckled 
sinuous duplex line, and a marginal side line, a lunular 
mark at the end of the cell, the lines slightly dilated 
at the costal end ; hind wing, pale brown, the costal 
border and the cilia, greyish-white ; thorax, head palpi 
and legs, greyish-white ; abdomen, pale brown ; thorax, 
slightly brown speckled ; sides of head and palpi, black- 
ish legs with black spots ; antennae ochreous brown, 
shaft white. 
"Female: fore wing greyish-white, irrorated with 
numerous brown scales, the transverse sinuous lines 
much less defined, being mostly apparent at the costal 
end and composed of scattered brown scales ; hind wing 
white, with a few brown scales from the anal angle; body 
greyish-white; thorax brown speckled; legs and antennae 
as in the male. 
" Expanse — male 1 J inches ; female 2j inches." 
Food-plants ; Moore quotes from Thwaites that the 
larvae feed on Erythrina indica, while from the above 
we learn that it also feeds on tea, sal, and Careya 
arborea. 
Parasites. — A considerable number of cocoons were 
sent to the Museum, but almost all of them were des 
troved by parasites, of whioh the most numerous in 
individuals was a tachinid fly. The pupae of the tachi 
nid were found in great numbers loose in the bottom 
of the breeding cage, where the larvae, after leaving 
the caterpillars in which they had developed, had no 
doubt been overtaken by their pupal stage, whilst en- 
deavouring to hide themselves in the ground after the 
manner of the " silk worm fly " with which they ap 
pear to be identical. A few chalcid parasites also 
emerged, and these Mr. P. Oameron has kindly ex- 
amined : be finds that they belong to two species, viz., 
Chalcis (Brdchi/meria) euplaa, and a new species of 
Peril ampus. Of these three species of parasites, the 
tachinid flies, no doubt, did by far the most exe- 
cution ; but the cbalcids must have accounted 
for a certain number of the pest, and altogether the 
parasites were so effective that out of a very consi- 
derable numbpr of cocoons of the pfst, which the 
writer attempted to rear, it was with difficulty that 
sufficipnt moths could he obtained for the identifica- 
tion of the species. If, therefore, the specimens sent 
to the Museum were at all representotive of those 
left on the hushes, but very few moths of the Febru- 
ary generation will have emerged to propagate the 
sppcies, and there can be little to fear from the pest 
next vear. 
Dasychira thwaitesii sepms to be singularly subject 
to the attack of parasites, for Mr. Fisher's experience 
* Lepidoptera, Ceylon, Vol. II, p. 98. 
in 1878 with the sal pest is almost identical with what 
has bpen above described, in the case of the tea Dent 
Mr. Fisher writes * : — 
"I collected several hundred chrysalids, intending 
to send sppcimens for identification, hut they all died 
whether from a disease or ichneumons I cannot now 
determine. Since May 1879 I have not noticed a 
single specimen of the insect." 
He considers that the mortality amongst the chry- 
salids may possibly bavebeen due to the unusual heat 
and dryness of the weather in March and Aoril 1879 
but the writer is inclined to think that j/asychira 
thwaitesii, like many ether insects, is continually kept 
in check by internal parasites, which have fuch vast 
powers of reproduction that, whenever their favourite 
food becomes abundant they multiply to such extent 
as very rapidly to destroy the grpat majority of the 
insects on which they feed, though they m\y never 
succeed in entirely extirpating them. 
The tachinid fly has not been described in this paper, 
as a considerable amount of information has been col- 
lected concerning it, and it would seem more appro- 
pjiate to consider it in connection with the t ilk worm 
of which it is so serious a parasite. 
Remedies. — If it sbould turn out, as now api ears pro- 
bable, that the tachinid which attacks the Jiasychira 
thwaitesii. in the same as tbe "fly" that destroys silk 
worms in Murshidabad and other parts of B 'ngal, it 
would seem to be well worth while to ascertain ' by 
actual experiment whether the increase of the pest 
cannot be more rapidly controlled by introducing fly- 
blown worms from tbe silk district than by waiting 
for the parasites to be introduced by accident. 
Besides any such possible method of controlling the 
pest, however, there can be no doubt but that, in any 
limited area, the caterpillars can be readily destroyed 
by arsenical insecticides, t though it has yet to be 
ascertained to what extent it will pay to employ 
these substances in India. 
The fact, observed by Mr. Fisher, that vigorous trees 
are not attacked to the same extent as tree* in an 
unhealthy condition, is worthy of notice »s being an- 
other instance of what would seem to be a very general 
law with insect pests. 
" Cut worms" are noticed as having injured paddy, 
and the remedy suggested is 
Bundles of cabbage, turnip, or clover are sprinkled 
with Paris green water and laid at intervals between 
the rows of the crop to be protected, but, before the 
plants come up, these poison the Cut worms, which 
are thus got rid of bpfore the appearance of the crop 
which they would otherwise attack. 
The scientific name of the " cut worm " is Agrotis 
suffusa. Dr. Riley of the United States is quoted 
to this effect : — 
"The larva has a most emphatic and pernioious 
cutth g habit. We have known it cut off large tomato 
plants that were over six inches in height, generally 
at an inch above ground. After severing one plant, 
the same worm would travel to other plants, and 
thus, in a single night, would ruin three or f >ur. In 
quite hard, clayey, corn-land, each worm wps found 
to have a smooth burrow, in which it lay hidden 
during the day, and to the bottom of which it could 
generally be traced. 
"Nothing seems to come amiss to its voracious ap. 
petite. It is reported as one of tbe species especially 
destructive to corn-fields and gardens. It destroys 
young tomato and tobacco plants, and, in confinement, 
feels with equal relish on apple and grape leaves, and 
has been found in a garden cutting off cypress vines ; 
it is also one of tha cotton Cut worms of the south." 
CEYLON TEA IN NEW ZEALAND. 
It is not going to be all smooth sailing with 
Mr. R, H. Taylor of Timaru with our Exhibition 
representative Mr. W. Watson, and with the new Com- 
pany—the Ceylon andlndianTea Assooiation, Limited, 
of Colombo and Calcutta, opened at Dunedin with 
Indian Forester,;,l. c. 
See Notes on Eoon.om.io Entomology, No. 2. 
