KILLING INSECTS. 



Fig. 8. 



wise mangled, the value of such a specimen is diminished 

 either for stud}* or the neat appearance of the collection. 



Besides the vapor of ether, chloroform and benzine, the 

 fumes of sulphur readily kill insects. Large specimens may 

 be killed by inserting a pin dipped in a 

 strong solution of oxalic acid. An excel- 

 lent collecting bottle is made by putting 

 into a wide-mouthed bottle two or three 

 small pieces of cyanide of potassium, which 

 ma} r be covered with cot- Fig. 7. 



ton, about half-filling the 

 bottle (Figure 7, after 

 Riley). The cotton may 

 be covered with paper 

 lightly attached to the 

 glass and pierced with 

 pin-holes ; this keeps the 

 insects from being lost in 

 the bottles. For Diptera, 



= ""-'■! fir * Loew recommends inois- 



■^ tening the bottom of the 

 collecting box with creosote. This is excel- 

 lent for small flies and moths, as the mouth 

 of the bottle can be placed over the insect 

 while at rest ; the insect flies up into tho 

 bottle and is immediately suffocated. A 

 bottle well prepared will, according to La- 

 boulbene, last several months, even a year, 

 and is vastly superior to the old means of 

 using ether or chloroform. He states, "the 

 inconvenience of taking small insects from a 

 net is well known, as the most valuable ones 

 usually escape ; but Irv placing the end of the 

 net, filled with insects, in a wide-mouthed 

 bottle, and putting in the cork for a few minutes, they will be 

 suffocated." A chloroform bottle with a brush securely inserted 

 in the cork (Fig. 8, after Rile}-) is often convenient. 



Pinning Insects. The pin should be inserted through the 

 thorax of most insects. The Coleoptera, however, should be 

 pinned through tlie right wing-cover (Fig. 9) ; many Hemiptera 



