Ciuadtan mntomolaijbl 



Vol. XLIII. LONDON, SEPTEMBER, 1911. No. 9 



ON COELOPISTHTA NEMATICIDA PACK., A CHALCID 



PARASIT1-: OF THE LARGE LARCH SAWFLY, 



LYG^ONEMATUS ERICHSONII HARTIG.* 



BY C. GORDON HEWITT, DSC, DOMINION ENTOMOLOGIST, OTTAWA. 



In the course of a study of the European and North American para- 

 sites of the Large Larch Savvfly, LygcE07iematus erichsojiii Hartig, which 

 was begun several years ago, observations have been made on the Hfe- 

 history of this Chalcid parasite. Its abundance in the cocoons of L. 

 erichsonii kept under observation would indicate that it is an important 

 factor in the natural control of the sawfly in the Eastern States and 

 Canada, and for this reason and also because hitherto it has been 

 undescribed, the present account is written. 



Packardf first referred to this parasite in the account of his investiga- 

 tions on Lygceonemaius erichsonii which were made immediately after the 

 latter insect had been discovered as a forest pest in the United States and 

 Canada. He says : 



"A number of cocoons sent us in 1SS2 by ^Vx. Atkins were found to 

 be in every case tenanted by a minute chalcid parasite, belonging to the 

 genus Fieromalus. If new it may be called Pteromahis nefnaticida 

 (Plate XII, Fig. 8). About a hundred of these issued from the cocoons 

 in the breeding-box during May, 1883. This parasite must, therefore, be 

 a most destructive enemy of the larch worm."' 



Beyond the figure of tlie parasite, which is given and again repro- 

 duced with the above account in the Fifth Report of the L'nited States 

 Entomological Commission (1S90), no further description is given. From 

 the correspondence ])rinted in this account of the injuries of the sawtiy it 

 would appear that Mr. Charles F. Atkins collected the aforementioned 

 cocoons in Maine. 



No further description of this insect, so far as I am aware, has been 

 published since Packard provisionally named it. 



*Contributicn3 from the Division of Entomology, Ottawa. 



tin "The Report of the Entomologist," "Ann. Rept. of the Commissioner 

 of Agriculture, 1883," Washington, D.C., pp. 138-142. 



