KILLHSTG INSECTS. 



wise mangled, the value of such a specimen is diminished 

 either for study 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 

 may 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, 

 "L Loew recommends mois- 



~ 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 the 

 bottle and is immediately suffocated. A 

 bottle well prepared will, according to La- 

 boulbeiie, 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 Avell known, as the most valuable ones 

 usually escape ; but by 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 Riley) is often convenient. 



Pinning Insects. The pin should be inserted through the 

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

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



