234 JAS. J. SIMPSON—ENTOMOLOGICAL 
air-bubble may be avoided by pressing the cork to one side when pushing it 
home. When the tube has been closed, the cork and the edges of the tube 
should be covered with melted wax to check leakage ; the wax from an ordinary 
stearine (or mining) candle will be found most satisfactory. The tubes must be 
returned in the wooden cases provided, and these should be carefully packed in 
a covering box or tin. 
IV.—INSTRUCTIONS FOR COLLECTING AND PRESERVING 
BED-BUGS (CIMICIDAE). 
COLLECTING.— When a house in the tropics is found to contain bugs, the tops 
of all the mosquito-nets should at once be examined, as that is a favourite resort 
for these insects. Bugs may also be obtained, when troublesome, by spreading a 
broad ring of pyrethrum powder right round the lower sheet or blanket upon 
which the sleeper lies; every bug that crosses this to attack him will be found 
more or less disabled in the morning. 
Where fowls are kept, the nesting-boxes should be periodically examined, for 
these will often be found simply teeming with bugs; and this should always be 
suspected when the fowls are found to be laying away from their boxes. Bugs are 
also to be found in some birds’ nests, especially those of swallows. Other species 
specially attack bats; these are mostly to be found in the cracks and crannies 
about the places where bats roost, and can be driven out by the use of ammonia 
or tobacco smoke ; sometimes the insects are found attached to the membrane of 
the bat’s wings, which should always be carefully examined. 
It is quite probable that on fuller investigation different species of bugs will 
be found frequenting the lairs of many other animals. 
Ki1LLinc.—These insects may either be killed in the cyanide bottle or dropped 
directly into the preserving fluid. 
PRESERVING.—Bed-bugs should never be preserved dry ; they should be kept 
in 60 per cent. spirit or 3 per cent. formalin. As far as possible, each tube 
should contain the bugs from only a single host. 
LABELLING and Pack1Nne.—See the instructions given for ticks. 
V.—DIPTERA (TWO-WINGED FLIES). 
INSTRUCTIONS FOR COLLECTING MOSQUITOS, AND 
OTHER SMALL OR DELICATE FLIES. 
CoLLectine.—Many species of mosquitos may be obtained during the day 
in shady woods or forests ; others prefer open, swampy ground, and can best be 
secured in numbers just after sunset; others again can be most conveniently 
collected in houses. When caught with a net in the open the insects should be 
brought home alive in glass-bottomed pill-boxes. In houses, it will be found 
that most of the mosquitos fly to the windows at dusk, and they may then be 
caught in the following way: Take a pill-box and firmly fix across the 
bottom a strip of blotting-paper, on which place a drop or two of chloroform 
or ammonia ; the box should then be put over a mosquito on the window ; in 
a few seconds the insect will be partly stupefied and can then be transferred 
at once to the cyanide bottle, the box being immediately placed over another 
insect, and so on; by this means a good series can often be obtained with 
