112 



ENTOMOLOGICAL NEWS 



[April, '22 



HBHBHMI 



A Carbon-tetrachloride Killing Bottle. 



By GAYLORD C. HALL, New York City. 



There has been a growing tendency for some years past to 

 use carbon-tetrachloride as a killing agent for insects. The 

 writer began experimenting with it several years ago and dur- 

 ing the last summer tried out seriously a killing bottle using 

 this fluid. The apparatus, which is shown in the accompanying 

 sketch, consists of a bottle of convenient size, in the bottom 

 of which is placed a piece of felt, which in turn is covered 

 by a layer of cotton. Carbon-tetrachloride is poured in until 

 the felt is saturated and the bottle is ready for use. 



The fumes of the tetrachloride 

 are very heavy and therefore 

 have a tendency to stay in the 

 bottle as long as it is not in- 

 verted. For this reason it is best 

 to remove specimens from the 

 bottle with forceps which reach 

 the cotton and thus keep the bot- 

 tle upright. Likewise in getting 

 the specimens from the net into 

 the bottle it is better to keep it 

 as nearly upright as possible. 



The effect of the tetrachloride 

 upon Lepidoptera is surprisingly 

 quick. Usually the insect has 

 ceased struggling and is lying 

 inert on the cotton (alas! with 

 wings reversed) by the time the 

 cork is replaced, that is, in a few 

 seconds. Should it be desirable to bring the wings back to 

 their normal position, the butterfly can be taken out, the wings 

 reversed, and dropped back again as with a cyanide bottle. I 

 have found that fifteen minutes is ample time for killing and 

 prefer to take the specimens out after that period has elapsed. 

 I always put them immediately into a metal box kept moist by 

 means of wet blotting-paper or otherwise, as that treatment 

 seems to prevent or at least minimize the rigor mortis. During 

 the last summer I caught and set several hundred specimens. 



