COLLECTING, PRESERVING AND APPLIANCES 23 



and been pinned the remaining larvse should be preserved 

 in a small phial, in rectified spirit, or in 4 per cent, 

 formaline solution, and marked with a distinguishing letter 

 or number in order to identify them with the adult pinned 

 insect. If spirit be used it is well to place the larvae in 

 dilute spirit for twenty-four hours, and then to change them 

 to rectified spirit. 



The appliances required for collecting are simple and 

 inexpensive, and, as a matter of fact, are better improvised 

 at home than obtained from a dealer's, as the articles they 

 manufacture are, as a rule, unsuitable for such extremely 

 delicate specimens as those of the Culicida, their nets in 

 particular being rarely fit to deal with anythmg less robust 

 than the larger Coleoptera , while their cabinets and boxes 

 rarely have sufficient provision for storing the large amount 

 of camphor necessary for the safety of the collection in a 

 tropical climate, unless one is to be continually examining 

 them and replenishing the supply. 



The first step in the preservation of collected specimens 

 is to kill the Mosquitoes, and for this the best plan is to 

 employ a " killing bottle," which any one can easily 

 manufacture for himself. 



Those supplied by dealers are always far too large for 

 small Diptera such as the Culicidce. 



Select a wide-mouthed phial about 3^in. high by 2in. 

 wide, fitted with either a well-fitting cork, or preferably, 

 with a metal screw-top. Most chemists store such bottles. 



In the latter case the disc of cork in the top of the cap 

 should be removed and replaced with one of thick rubber, 

 which may be secured in position by means of ordinary 

 bicycle tyre-repairing cement. Mix equal bulks coarsely 

 powdered cyanide of potassium and dry plaster of Paris, 

 and put a depth of ^in. in the bottom of the bottle; dust 

 over this a little dry plaster, and then pour over all ^in. in 

 depth of liquid plaster of the consistence of cream — when 

 the plaster has set the bottle is ready for use. 



A bottle such as this is very handy for slipping over and 

 catching sitting Mosquitoes, as in a few seconds the insect 

 is stupefied, and drops into the bottle uninjured by attempts 



