712 
THE TROPICAL AGRICULTURIST, 
they first appear. If the earlier broods are systematically collected and destroyed, no further trouble 
will be experienced. 
When visiting in the Kelani Valley recently, I was informed that crows were very active 
agents in destroying "nettle grubs." During a bad attack of the pest the crows were eaid to have 
gorged themselves with the caterpillars vmtil they could scarcely rise from the ground. They 
should be encouraged in every way. 
Dichocrosis imnctiferalis, Guen. — The " Cocoa-pod Borer," which is the caterpillar of the 
Pyralid moth, B. imnctiferalis, was troublesome in the Kandy district in March. The local treat- 
ment, which appears to be very successful, is to employ a force of small boys to examine the growing 
fruit. Whenever signs of the borer are observed, a few drops of kerosine oil are run into the tunnel 
of the insect, when the little grub immediately wriggles out and is captured. When the hole does 
not penetrate into the seed cavity, the application does not injure the pod. 
'•''Tobacco Pest r — What may prove to be a rather serious pest has destroyed all the young 
tobacco plants in the experimental plots in the Peradeniya Gardens. The disease is characterized by 
a swollen condition of the stem, producing very much the appearance of a half-grown knol-kohl 
plant. On cutting open this swollen part the tunnels of a small caterpillar are found. Eventually 
decomposition is set up, and the plant rots away. Specimens of the caterpillars, kept in captivity, 
turned into minute brown Tineid moths, examples of which have been forwarded to England for 
determination. The pest was noticed this year only in Peradeniya, but a Tamil cultivator from 
JafEna reports that the same disease is known in the north of the Island. The only possible 
treatment is the immediate removal and destruction of the affected plants. On inquiry from the 
Botanic Gardens, Buitenzorg, Java, I am informed that an identical or closely related disease occurs 
on the tobacco plant there. This disease is there locally known by the name of " dikbuikziekte," 
which may be literally translated as the " paunch-belly sickness," a highly descriptive name. 
The " Tea Tortrix," Capua coffearia, Nietner, still gives occasional trouble upcountry. This 
pest has been fully dealt with in the Royal Botanic Garden Circular No. 19. * 
Boarmia hliurmitra, Walker. — A case of rather extensive injury caused by caterpillars of this 
moth affords an interesting instance of how a hitherto obscure insect may suddenly assert itself as a 
dangerous pest. The caterpillar belongs to the family Geometridce, many of which assume, when at 
rest, the appearance of a piece of dead stick. The species is by no means uncommon, but, until this 
last year, has not gained any notoriety as an enemy to cultivated plants. It has, however, quite 
recently appeared in immense numbers on a few estates in the Kandy District, and, after defoliating 
the Grevillea trees, has attacked the tea. When full grown, the caterpillar buries itself in the ground 
and turns into a smooth reddish chrysalis. The moth is of a dull brown colour, very finely mottled 
with darker specks, and is difficult to distinguish when resting on a rock or tree trunk, though, 
when found, it is easily captured, as it seldom attempts to flyaway. The coolies soon become adept 
at seeing and catching them. On one estate it was estimated that over 50,000 had been killed in 
this manner. At the time of my visit the caterpillars were dying off from some fungal disease. 
It was noticeable that there were few birds on these particular estates. Where there are abundant 
small birds they would be most valuable asistants in checking the increase of the pest. 
" Cardamom Borer'''' (Bichocrosi's evaxalis. Walker). — The larvae of a Pyralid moth, B. evaxalis, 
have been troublesome in parts of the Matale and Rangala districts. The caterpillar tunnels into the 
mature stems of cardamom plants, making its entrance at one side and boring either upwards or 
downwards, eating the pith and causing the death of those particular stem?. After the caterpillar 
has vacated them the* tunnels often become tenanted by ants, the presence of which first attracts the 
attention of the superintendent, who, not unnaturally, attributes the damage to the ants themselves. 
The presence of the borer may be detected by the accumulation of pellets of excrement at the base 
of the injured stems. The affected stems should be at once cut and destroyed. 
Nepita conferta^ Walker. — In August immense numbers of the small hairy caterpillars of this 
moth were invading the bungalows, swarming upon every rock and piece of brickwork, and 
wandering over the roads and garden paths. This insect is not mentioned here on account of any 
damage attributable to it, for, with the exception of inconvenience caused by its occasionally coming 
in accidental contact Avith one's person and leaving its irritating hairs in one's skin, it is quite 
harmless. The caterpillar feeds only upon minute lichens and algse growing on rocks and stones, 
and will not touch any of the higher plants. But the appearance of such thousands of caterpillars 
often causes unnecessary alarm to those who do not know the habits of the insect. 
Agroth C-nigrtmi, Linn. — The sudden appearance of the caterpillar of this moth on a young 
tea clearing in Bogawantalawa is another instance of the unexpected increase of an insect hitherto 
considered somewhat of a rarity in Ceylon. The attack seems to have been only temporary, the pest 
disappearing almost as suddenly as it arrived- 
