ELEMENTARY ENTOMOLOGY 



and the plaster of Paris set. After this the bottle should always be 

 kept corked, so as to retain the strength of the cyanide. The ad- 

 vantage in putting the dry plaster of Paris in first is that it absorbs 

 the moisture and will keep the bottle dry longer than if the wet 

 plaster is poured directly over the cyanide. It will also be found 

 advantageous to place a few strips of dry blotting paper in each 

 cyanide bottle, as this serves the double purpose of helping to 

 absorb the moisture and preventing the insects from shaking about. 



After the insects are caught in the net, they 

 should be transferred to the cyanide bottle, 

 which, if properly constructed, will stupefy 

 them in a few seconds. Insects, especially 

 beetles, should not be removed from the 

 bottle for an hour, although Hymenoptera 

 and Diptera will be killed within ten minutes. 

 If the cyanide is too dry, it does not act so 

 rapidly, and a few drops of soda water will 

 greatly increase its efficiency. Very small 

 cyanide bottles may be made by placing a 

 piece of cyanide in the bottom, covered with 

 cotton or blotting paper. 



If possible, only insects of the same size 

 should be placed together in the cyanide bot- 

 tles. Fragile insects, or those with scaly wings, 

 should not be put in with the general collection. 

 Chloroform bottle (Fig. 474). While not an 

 absolute essential to the collecting of insects, 

 the chloroform bottle will be found one of the 

 most valuable assets, especially to the collector of Lepidoptera. 

 One of the most convenient forms consists of a small-mouthed 

 bottle, into the cork of which has been inserted a camel's-hair 

 brush. These will be found most useful in collecting very small 

 insects or butterflies. In collecting very small insects, touching them 

 with a brush moistened in chloroform is sufficient to kill them, and 

 at the same time the insects will adhere to the brush and may 

 thus be transferred to the storage bottle or box. In collecting 

 Lepidoptera the sides of the thorax should be moistened with the 

 chloroform before placing them in the cyanide bottle. 



FIG. 474. Chloroform 



bottle with a brush 



stopper 



(After Banks) 



