INSECTS INJURIOUS TO CONIFERS. 



153 



collector, is not the same as that of the economist, and papers 

 written by the one will not always serve for the enlightenment of 

 the other. The former is apt to neglect certain small points 

 bearing on the habits of the insect which do not immediately con- 

 cern him, and especially those connected with the appearance, 

 vitality, and aftergrowth of the plant on which his prey lives ; 

 while the economist, more particularly the practical forester, 

 who thinks more of the injured plants than of the destroyer, has 

 occasionally a royal disregard of the sordid details of specific 

 characters, which brings him into trouble when he discovers 

 that closely allied species often have remarkably different life- 

 histories. In writing the account of any new injurious insect it 

 is essential that an exact determination of the species shall 

 be made, and the life-history constructed as completely as 

 possible from personal observation, especially with regard to 

 times of appearance, or if already recorded it should be verified 

 by observed facts. 



It would not be difficult to compile a complete list of British 

 Conifer-feeding insects by collating such lists covering the whole of 

 Europe with our systematic catalogues, and by searching scientific 

 papers, and their biographies might be written by supplementing 

 the deficiency of British observations with the work of con- 

 tinental authorities. But such an account would not be satis- 

 factory. The times of emergence and number of broods of a 

 species, the habits and food-plant, often differ in different 

 countries. The process of leaning upon the observations of others 

 can be carried too far, and not a few pitfalls await him who tries 

 to write the life-history and economy of a British insect from 

 materials collected in foreign countries. That of Liparis 

 monacha, for example, would be singularly wide of the mark. 



I propose in this paper not to surmount the difficulties which 

 stand in the way of giving an exhaustive account of our Conifer- 

 feeding insects, but to touch briefly on the few important and 

 well-known kinds, and especially on those points in the habits of 

 each which are directly concerned with practical treatment. 

 Unable as I have been to examine, in the intervals left by other 

 work, the mass of scattered information on the subject of attacks 

 in Great Britain, I cannot claim any special authority for, or 

 novelty of information in a paper put together with the assistance 

 of such literature as has been accessible. But the ignorance of 



