CHAix:;iDiD^. 205 



against the attacks of this insidious foe, is to burn the stubble 

 in the autumn or spring for several successive years. Plough- 

 ing in the stubble does not injure the insects, as they can 

 work their way out of the earth. 



It has been objected b}^ Westwood, Eatzburg, and more 

 recently by Mr. Walsh, (who afterwards changed his views), 

 that as all the species of this family, so far as known, are para- 

 sitic, the Eurytoma cannot be a gall-producer, and that the 

 galls are made b}^ a dipterous insect (Cecidomjia) on which 

 the Eurytoma is a parasite ; but, as they offer no new facts to 

 support this opinion, we are inclined to believe from the 

 statements of Harris, Fitch, Cabell, T. Glover (Patent Office 

 Report for 1854), and others, that the larva of the Eur^i^oma 

 produces the gall. We must remember that the habits of 

 comparatively few species of this immense family have been 

 studied ; that the genus Eurytoma is not remotely allied to 

 the Cynipidae, or true gall-flies (which also comprise animal 

 parasites) , in which group it has actually been placed by Esen- 

 beck, for the reason that in Europe "several species of 

 Eurj'toma have been observed to be attached to different 

 kinds of galls." (Westwood.) Dr. Fitch also describes the 

 Yellow-legged Bai'lej'-fly, Eurytoma flcwipes, which produces 

 similar galls in barley, and differs from the Wheat Joint- worm 

 in having yellow legs, while the antenna? of the male are not 

 surrounded with Avhorls of hair. The Eurytoma secalis Fitch 

 infests r^-e. It differs from E. hordei in "having the hind pair 

 of shanks dull pale-yellow, as well as the forward ones." AVe 

 shall also see l)eyond that several species of Saw-flies produce 

 true galls, while other species of the same genus are external 

 feeders, which reconciles us more easily to the theory that the 

 Eurytoma hordei, and the other species described by Dr. Fitch, 

 differ in their habits from others of the family, and are not ani- 

 mal parasites. Indeed the Joint-worm is preyed upon hy two 

 Chalcid parasites, for Harris records finding the larvae, proba- 

 bly of Torymus, feeding on the Eurytoma larvae, and that a 

 species of Torymus (named T. Harrisii, by Dr. Fitch, and per- 

 haps the adult of the first-named Torvmus) and a species of 

 Pteromalus are parasites on Eurytoma. 



In Monodontomerus (Torymus) the third joint of the an- 



