190 Brt» THE J° URNAL 



OF THE 



BOARD OF AGRICULTURE. 



Vol. XV. No. 9. 



DECEMBER, 1908. 



THE LARGE LARCH SAW-FLY. 

 C. Gordon Hewitt, M.Sc, F.E.S. 



Lecturer in Economic Zoology, University of Manchester. 



An account of the Large Larch Saw-fly (Nematus erichsoni) 

 has already been given in this Journal* In it Packard's 

 account of its life-history as well as the history of the pest in 

 America and Europe, was summarised, but as the insect was prac- 

 tically a new pest, its life-history and bionomics had not been 

 studied in this countty . The present paper is intended to supple- 

 ment MacDougall's account, and contains the results of a study 

 of the life-history, parasites, and natural enemies of the saw-fly, 

 together with recommendations as to remedial and preventive 

 measures resulting from the investigation. The complete 

 manner in which the previous history of the pest is given in 

 Packard's careful description^ of its occurrence in the United 

 States of America, and in MacDougall's resume, makes it un- 

 necessary to repeat this information here, and the subject is now 

 taken up at the point at which these authors left off. 



The egg, larva, female saw-flies and cocoons have been 

 described, but the male, so far as I am aware, has not been 



* MacDmga.il) R. S. "The Large Larch Saw-fly {Nematus erichsmi)." 

 Journ. Board of Agriculture, vol. xiii, pp. 385-394, 1 pi., October, 1906. 



t Packard, A. S. Fifth Report of the United States Entomological Commission, 

 "On Insects Injurious to Forest- and Shade Trees" (/V. erichsoni), pp. 879-890, 

 pis. ix and xxvi. 



(45 1 1) 2 T 



