Sessional_Paper_1894 — Page 339

335

No. 25

94

No. 36.

HONGKONG.

REPORT ON THE CATERPILLAR PLAGUE BY THE ACTING SUPERINTENDENT, BOTANICAL AND AFFORESTATION DEPARTMENT.

Laid before the Legislative Council by Command of His Excellency the Governor.

BOTANIC GARDENS, HONGKONG, 10th July, 1894.

SIR,--I have the honour, in compliance with your request of the 3rd instant, to forward the following report on the Caterpillar Plague.

DISCOVERY AND PREVENTION.

The caterpillar which has been attacking the Pine trees (Pinus sinensis, Lamb.) in nearly all parts of the Island and Kowloon, is the caterpillar of a large moth (Eutricha punctata, Walk.).

2. It was first seen this year towards the end of April, when the insects were not more than two or three lines in length.

3. At that time the pest had not commenced its ravages, but knowing its habits by past experience, and in view of the fact that the numbers were greatly in excess of anything seen before, as many as two and three hundred being observed on a single tree, representations were made to the Government, to the effect that the Chinese should be invited to collect them, and that all brought in should be paid for by weight.

4. The Government readily consented to the suggestion, and the Captain Superintendent of Police kindly agreed to allow the caterpillars to be brought into the Police Stations nearest to where they were collected. The Botanic Gardens' Office was also a receiving station.

5. The method of catching these pests was by shaking the trees and then picking up the insects from the ground by means of pincers, or with the fingers enclosed in cloth. A sudden shake of the tree brought most of the caterpillars down, but they soon re-gained their former positions unless prevented from doing so.

6. When the insects were brought in to the Police Stations, they were destroyed by pouring boiling water over them, or some other efficacious substance, as sea water, after which they were buried, due precautions being taken that everything was carried out satisfactorily from a sanitary point of

view.

DURATION.

7. The length of time the plague has lasted may be put down as two months-from the end of April to the end of June. The first lot brought in by the Chinese was on May 24th, and the last on June 28th. No cocoons were observed until the beginning of June, when arrangements were at once made to have them collected and paid for in the same way as the caterpillars. The first lot of cocoons brought in was on June 6th, and at the present time they are still being collected, although the quantities are becoming less and less. In all probability the cocoons would have been all collected by this time, were it not for the difficulty of getting coolies to do the work, owing to the great scarcity of labour in the Colony during the last few weeks.

QUANTITIES.

8. The quantity of caterpillars brought in and paid for, at the various Police Stations and the Botanic Gardens, was over 60,000 catties, or nearly 36 tons. Cocoons to the weight of 5,000 catties have been received up to date. There were 511 caterpillars in the particular catty counted, and the cocoons numbered 800 to the catty. This gives the enormous number of 35,000,000 insects destroyed, to say nothing of future generations.

COST.

9. The expense of getting rid of the scourge has been about $5,000, or an average of 7 cents. per catty for both caterpillars and cocoons. The price paid per catty was varied according to the quantity of caterpillars and cocoons found in the several districts. From four to fifteen cents have been offered for caterpillars, although the latter price failed to attract collectors when the insects had become scarce.

Cocoons have been paid for at a price varying from twenty to forty cents per catty.