[Ill] COLLECTmG AND PRESERVING INSECTS RILEY. 



MOLD. 

 Collections kept in damp x)laces or in a moist climate are very liable 

 to mold, and under such conditions it is difficult to avoid this evil. 

 Carbolic acid is recommended, but Mr. Aslimead, who has kept a large 

 collection in the moist climate of Florida, has found the use of naphtha- 

 line much more satisfactory. Mr. Herbert H. Smith who has had more 

 extensive exxDcrience in the tropics prefers the carbolic acid. Moldy 

 specimens maybe cleansed by washing with carbolic acid applied with 

 a fine camel's hair brush. 



VERDIGRISING- AND GREABING. 



The action of the acid juices in the bodies of certain specimens — as 

 many of the Lepidoptera, Coleoptera, and Diptera — will cause the forma- 

 tion of verdigris about the pin, which in time accumulates and disfig- 

 ures and distorts the specimen, and ultimately corrodes the pin, so 

 that the slightest touch causes it to bend or break. There is no pre- 

 ventive yet known for this trouble other than the use of pins which have 

 no brass to be corroded. Japanned pins are made for this purpose, 

 and are, on the whole, satisfactory, but they bend easily and some cau- 

 tion is required in handling them. In place of these pins, which are 

 somewhat more expensive than the steel pins, iron pins may be used. 

 These are very soft and bend too easily for satisfactory use. The steel 

 pins may be rendered available for use by an immersion in a silver bath, 

 which is comjDaratively inexpensive. 



Insects the larvae of which live in wood are particularly subject to ver- 

 digris, as the Cerambycidse and Elateridse in Coleoptera, the Uroceridai 

 in Hymenoptera and Sesiidae in Lepidoptera. In Hymenoptera the 

 families Formicidse, Mutillidse, and the endophytous lenthredinidre ver- 

 digris very rapidly, and most Diptera also. With all these insects ja- 

 panned or silvered pins should be used, or when not too large the 

 insects should be mounted on triangles. This verdigrising is associated 

 with what is known as greasing, and this, as just indicated, is also 

 associated with endophytous larval life. The verdigris may be pre- 

 vented by the methods indicated, and I would strongly advise, as a 

 good general rule to be followed, the rejection of the ordinary pins for 

 all species which, in the larva state, are internal feeders. But there is 

 no way of preventing greasing or decomposition of the fats of the 

 body, which may affect a specimen years after it has been in the 

 cabinet. If the specimen is valuable the grease may be absorbed by im- 

 mersion in ether or benzine, or by a longer treatment with i^owdered 

 pipe- clay or plaster of Paris. Insects collected on seabeaches, and 

 saturated with salt water, also corrode the common steel pin very 

 quickly and should be mounted on japanned pins. It is also advisable 

 to rinse such specimens thoroughly in fresh water before mounting. 



The conviction has been forcing itself on my mind for some time that 

 the naphthaline cones tend to promote greasing and verdigris, and 

 carbolic acid in some small vessel secured to the cork, were, perhapS; 

 preferable. ^ 



