RESEARCH IN BRITISH WEST AFRICA. 235 
comparatively little trouble. These insects often collect in some numbers 
during the day on the thatch inside native huts, and many may be captured 
with a few sweeps of the net; special attention should also be given to those 
species which attack domesticated animals. Mosquitos may be bred quite 
easily from larvae, and this method of collecting should be adopted whenever 
practicable. 
The minute insects known as “sand flies” (Simulium, Phlebotomus and 
Culicoides) should be carefully collected.  Simulium, so far as is at present 
known, breeds in shallow running streams. The larvae attach themselves to 
the stems of plants and stones ; when matured, the flies are readily bred by 
placing the larvae zn sztw on portions of the plant or on stones in a glass vessel, 
which should be covered over with a piece of rubber sheeting. Water must not 
be added or the larvae will die off rapidly. The plants or stones, however, must 
be kept moist. Phlebotomus may be looked for in latrines and damp shady places. 
Culicoides often swarm along rivers and elsewhere ; the members of this genus 
are all minute, and examples should be preserved in alcohol as well as in a dry 
condition. 
KriLiinc.—When the mosquitos, &c., have been brought home alive, they 
may be killed by the method described under the heading “ Brass chloroform- 
bottle.” Ammonia may be used instead of chloroform, but on no account should 
they be shaken into the killing bottle as they are thus inevitably damaged. The 
boxes should be afterwards left open some time before being used again for live 
insects. 
PRrESERVING.—For all general purposes it is desirable that mosquitos should 
be preserved dry. Specimens to be identified must on no account be placed in 
spirit. Mosquitos must be dealt with as soon as possible after death, for they 
very rapidly become dry and stiff, in which state they cannot be touched without 
breaking and are therefore useless for transmission. 
The insects may be sent home either pinned or unpinned. If pinned, the 
following process should be adopted. Cut a small piece of paper of suflicient 
size to write on it all data connected with the specimen to be pinned, as follows : 
name of locality, including altitude if necessary ; date—day, month, year—thus, 
9. XI. 98; collector’s name; any remarks of interest, e.g., “ Most troublesome 
species in district,” “ Abundant only in open swamps,” ‘“ Uncommon,” &e. 
Then take one of the fine No. 20 pins and thrust it through the middle of the 
mosquito’s thorax on the upper side, gently pushing the insect two-thirds of the 
way up the pin and taking great care not to break off the legs; this may 
conveniently be effected by stretching a corner of a handkerchief between the 
fingers and then gently pushing the pin through the fabric. 
In the case of mosquitos, a good number of specimens of each species (but not 
more than half) should be pinned through the side of the thorax instead of from 
above ; while the majority (say two-thirds) of the midges and sand flies should 
be pinned in this manner. Then place the paper on a piece of cork or peat with 
the writing downwards, seize the pin with the forceps (below the specimen) and 
thrust it through the paper, and finally, with a pin, arrange the wings so that 
they project at an angle from the body and dispose the legs symmetrically. 
This latter operation must be performed very gently, and care must be taken 
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