Vol. xxi] 



ENTOMOLOGICAL NEWS 



409 



KILLING- "BOTTLES. 



should get wet, the paper bag inside will generally remain 

 dry enough to get out the catch safely, and may be renewed 

 as often as necessary, thus eliminating any danger along this 

 line. Another advantage, is that the most minute insects are 

 retained, being unable to work their way out as they would 

 through the bobbinet. It is also much easier to kill the catch 

 than the usual method of putting the end of the net into a 

 large bottle and waiting. To extract the paper bag after sweep- 

 ing, grasp the pocket about one inch below its junction with 

 the cone, firmly with one hand, and with the aid of the other 

 reach in and pull the paper bag out through the small hole, all 

 the while keeping the top of the bag pinched tight. 



With the idea of keeping the catches from the various 

 places or habitats separate, but more especially to keep them 



clean and dry, I use a number of 

 small killing-bottles in preference 

 to a few larger ones; although a 

 medium size bottle is preferable 

 for killing, while the smaller ones 

 are used for keeping the catch in 

 after killing. I use tubular vials 

 without neck, as shown in an ac- 

 companying sketch, the larger 

 about \ l /2 inches and the smaller 

 % inches in diameter. In the bot- 

 tom of each is placed a little cot- 

 ton and a few lumps of potassium 

 cyanide, then a little more cotton ; 

 upon this press down a snugly 

 fitting cork disk in which has been punched three to 

 five Y% inch holes. A disk of white blotting paper press- 

 ed down on top of this completes the operation and the 

 bottle is ready. All this should take up about y 2 to ^4 inches 

 of the bottle. The blotting paper disks should be renewed as 

 soon as they become moist or discolored, as they serve the 

 purpose of keeping the insects from contact with the cork 

 disk which soon becomes moist from the cvanide. Binding a 



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