INSECTS INJURIOUS TO CONIFERS. 71 



A CucurMtaria (C. pitliyophila), reported as occurring on the 

 cortex of living and dead branches of Coniferae, also requires investiga- 

 tion. The same remark applies to Cooke's Asterina cupressina on leaves 

 of Cupressus, and to Saccardo's Meliola Abietis on Abies, Ellis's 

 Coryneum Juniperinwn on leaves of American Junipers, Cooke's DotJiidea 

 halepensis on Pines and D. spJiceroidea on Junipers, and the Pleospora 

 laricina of Rehm ; also a large number of as yet very obscure forms, 

 such as Sphcerella, Stigmatea, etc., etc. 



With regard to a large number of these forms, and to even more 

 numerous foreign forms, we are as yet quite in the dark as to whether 

 they are parasites or not. 



Experience warns us, however, that in many cases, epidemic fungus- 

 diseases suddenly force themselves on our attention owing to some form, 

 hitherto occurring sparsely and known only to the curious expert, having 

 become suddenly favoured in its struggle for existence. I have already 

 given you several examples, notably that of the Larch-disease, into the 

 life-struggles of which we have succeeded in peering rather deeply. 

 Surely such considerations should alone suffice to extend and cement that 

 sympathy between the practical horticulturist and the persistent, though 

 perhaps unobtrusive, investigator which, I am happy to see, is becoming 

 more and more pronounced as each understands better the ways and 

 high aims of the other. 



It should be borne in mind, finally, that plant-diseases, like human 

 diseases, cannot be fully elucidated by a layman though it is astonish- 

 ing how frequently the contrary assumption is acted upon in the case 

 of both. There seems to be a fatal temptation in the idea of disease 

 to the minds of most men, and the consequence is quackery or even 

 disaster. 



INSECTS INJUEIOUS TO CONIEEPwE.* , 

 BY MR. W. F. H. BLANDFORD, M.A., E.Z.S. 



OF all families of trees, the Conifers suffer most severely from the 

 attacks of insects, owing to the large number of species which they 

 support, and to the difficulty which, on account of their physiological 

 characteristics, they have in withstanding injury. The wide area 

 over which forests of these trees extend increases the danger of 

 insect-attacks in accordance with a well-known law which holds with 

 injurious insects, and it is among Conifers alone among trees, and 

 among the forest species of Pine, Fir and Larch that have happened 

 those repeated instances of widespread destruction over large forest 

 areas which, occurring even before economic forestry began to change 

 the character of the primitive mixed woods, probably increased in 

 number and severity at that epoch, and have continued at intervals 

 to the present clay. 



* Abridged from the Report of the Conifer Conference by permission of the Council of 

 the Royal Horticultural Society. 



