1906.] Introduction of Insects into the U.S. 623 



If, however, for any reason the suggested treatment cannot be 

 carried out, the following points should have attention : — 



1. The careful isolation of new timber. To put such in the 

 same chamber or shed with wood already infected is to invite 

 attack. 



2. Before being put aside for storing, new timber should be 

 examined, and any holes made by the insect treated with corro- 

 sive sublimate, or with a mixture of carbolic acid and benzene. 



3. Any timber that could conveniently be stored in air-tight 

 chambers would receive protection by tiny phials of naphthalin 

 placed here and there in the case or chamber. Such phials 

 should be left unstoppered. Such treatment could, of course, 

 only be applied to small timber. 



4. A careful examination should be made of the infested 

 -stock. The worst attacked should be burnt ; the least at- 

 tacked could have the " holes " treated individually. 



The spread of the pest could also be checked by surrounding, 

 where practicable, the infected wood with coarse cotton, or with 

 sacking, until ready for use. The beetles, which would issue 

 from the timber, would be kept from spreading, and would be 

 shaken from the sacking into paraffin. For very large timber 

 that cannot be protected in this way nothing but complete 

 isolation can effectually prevent the spreading of the beetle. 



There are many species of insects of great service in 

 destroying other insects which are injurious to crops,* and 



United States. pests. Not very much has been attempted 



an experimental importation of Californian ladybirds (^Hippo- 

 damia coitverg ens) was made in 1903. {Journal^ r ol. X.,p. 501, 

 March, 1904.) 



Considerable activity in this direction has been displayed in 

 recent years in the United States, and the Secretary for Agri- 



* See article on " Beneficial Insects," Journal, Vol. V., p. 326, Dec, 1898. 



Introduction of 

 Beneficial Insects 

 into the 



efforts have lately been made in many 

 countries to introduce and acclimatise those 

 which are known to prey upon common 



in this way in the United Kingdom, but 



