627916-1899-Circular-Despatch-Investigation-of-Malaria — Page 3

90 THE HONGKONG GOVERNMENT GAZETTE, 28TH JANUARY, 1899.

TO PIN A MOSQUITO.

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Take a card disc and write on it all the data connected with the specimen to be pinned, as follows (1) Name of locality, including altitude if necessary; (2) date-day, month, year-thus, 9. 11. 98; (3) collector's name; (4) any remarks of interest, e.g., "Most troublesome species in district "Abundant in bamboo-jungle”; Uncommon," etc. Place the disc on a sheet of cork-carpet or pith, and picking up with the entomological forceps one of the fine No. 20 pins, thrust about one-third of an inch of it through the centre of the disc; in doing this the pin should be held by the forceps below the middle, otherwise, owing to its fineness, it may bend and fail to pass through the card. Lay the specimen on its back (turning it over with the aid of a needle or one of the No. 20 pins held in the forceps), and thrust the pin, which now carries the disc, through the centre of the thorax, between the bases of the legs, until the tip of the pin projects one-sixth of an inch beyond the dorsal surface of the thorax ;* invert the disc (the specimen will then be right side up), and thrust an ordinary pin through the disc near the margin for the purpose of carrying both disc and specimen. The next and last thing to be done is to arrange the legs and wings as far as possible; i.e., the wings must be made to project at an angle from the body, and not allowed to remain closed, and the legs must be disposed symmetrically on the card disc so that all parts of them can be readily seen, instead of being left crumpled up beneath the body. These operations must be performed as gently as possible with the help of a needle mounted in a handle, or by the aid of a No. 20 pin held in the forceps, and care must be taken that hairs and scales are not rubbed off in the process. As the tissues contract in drying, the legs and wings are very apt to get pulled out of place, and, to correct these changes, the specimens should be examined once or twice during the next day or two after being pinned.

TRANSMISSION OF SPECIMENS TO ENGLAND.

Pinned specimens of mosquitoes, like those of other insects, rapidly develop mould during the rainy season in tropical countries, and since mouldy specimens are practically worthless for purposes of scientific determination, the insects should be sent home as soon as possible after being collected. To contain the specimens, if a proper entomological store-box is not available, any small strongly-made box (such as a cigar-box) will serve, in the bottom of which a layer of cork-carpet or pith (not less than half an inch thick, in the case of the latter) is firmly fixed. The greatest cure must be taken to prevent specimenis getting loose and rolling about in transit, since in this way a single loose disc might easily destroy or hopelessly damage all the other specimens in the box. To prevent this the pins supporting the cards should be inserted as tightly as possible int the cork-carpet or pith, and they should all be driven in to the same level; if this is done a sheet of soft

does paper (newspaper very well) can be feed into the box, resting ou the heads of the supporting pins, in order to minimise the damage should a dise happen to get loose. The box containing the specimens should be well- wrapped in cotton-wool, or similar material, and firmly packed in an outer box for transmission (by Parcel Post) to England.

N.B.-NOT ONLY MOSQUITOES, BUT ALL DIPTERA should be Collected, PrepARED, AND SENT HOME

IN THE MANNER ABOVE DESCRIBED.

The above instructions, though drawn up with special reference to mosquitoes, are equally applicable to the collecting of Diptera in general, except that in the case of the large forms, such as horse-flies (Tabanida), robber-flies (Asilidæ), etc., it is not necessary to use so fine a pin as a No. 20 (D. F. Tayler and Co.'s entomological pin No. 5-price 1s. 6d. per ounce--would do instead).

ÅDDRESS FOR SPECIMENS.

Specimens of mosquitoes (or other Diptera) intended for the British Museum should be directed to

THE BRITISH MUSEUM

(NATURAL HISTORY),

CROMWELL ROAD,

All communications on the subject should be addressed to the Director.

LONDON, S.W.

* Should it be found impracticable to proceed in the manner here prescribe, owing to the difficulty of making the specimen lie in the required position on its back, it may be pinned in the ordinary way through the middle of the thorax from the dorsal side; in this case, however, the specimen must be pinned first (ie., before it is mounted on the card dise); it should be drawn two-thirds of the way up the pin, and the latter should then be thrust through the flise, holding the pin with the forceps below the specimen; mount the dise on a common pin, as in the first method.