PEE FACE. IX 



Dr. J. Eitzema Bos, Director of the Phyto-pathological 

 Laboratory at Amsterdam, for kind assistance during many 

 years in identification of Nematoid Worms, known with us as 

 Eelworms ; to Dr. A. Nalepa, of Vienna, the distinguished 

 observer and writer on Phytoptid?e, I am indebted for much 

 help regarding Gall Mites ; and to Mr. Albert D. Michael, 

 our own well-known acarinologist, for assistance in study 

 of various of the Acarina injurious to crops. To Dr. J. 

 Fletcher, Entomologist of the Department of Agriculture of 

 the Dominion of Canada, and to other good friends whose 

 help I have endeavoured fully to acknowledge accompanying 

 their information, I beg to express my hearty thanks, as 

 also to Mr. Oliver E. Janson, F.E.S.Lond., for much help 

 given me, especially in identification of doubtful species of 

 Coleoptera. 



Amongst the illustrations, amounting to somewhat more 

 than sixty in number, I beg to acknowledge with thanks 

 those at pages 29, 151, and 246, as being by kind permission 

 of Messrs. Blackie, of Glasgow ; the moths in the figures at 

 pages 16, 86, 133, 177, 179, 260, and moth with wings spread 

 at page 89, are from Newman's ' British Moths ' ; those at 

 pages 21, 27, 54, 210, and the moth with wings closed and 

 caterpillar at page 89, are figures of which the use was granted 

 me some years ago by the editor of the ' Gardeners' Chronicle.' 

 Of the other figures, a large proportion have been drawn 

 expressly for my publications by Messrs. Horace and E. C. 

 Knight, artists on the staff of Messrs. West, Newman & Co., 

 54, Hatton Garden, E.C. ; and the others, I hope, will be 

 found to have been duly acknowledged, either together with 

 the figure, or in the letterpress accompanying. 



The frontispiece is, by permission, from a photo by Messrs. 

 Elliott & Fry, of Baker Street, London, W. 



So far as our experience shows, the protection of our fruit 

 crops from insect ravage is likely to be an increasing difficulty, 

 consequently on the increasing extent of the areas in which 

 one kind of orchard tree or fruit bush is grown year after 

 year, thus giving every opportunity for the established settle- 



