habits of certain species of Eurytomides. 313 



succeeded in obtaining from the diseased wheat-straw so 

 much as a single specimen of Cecidomyia, while both the 

 wheat and the barley straw have yielded to several 

 observers, in repeated instances, numerous specimens of 

 the same kind of Eunjtoma, and nothing else, saving an 

 extremely small number of lesser parasites. The 

 determinations of this difficult and interesting question 

 is of much importance in a scientific and an economical 

 point of view. We are to consider, in destroying the 

 Eurytoina, whether we shall kill an enemy or a friend. If 

 it be a parasite, as the almost universal opinion of ento- 

 mologists would lead us to believe, it would be the height 

 of folly to attempt to interfere with its operation. On 

 the other hand, if we can show it to be a plant-eating 

 insect, we may use such means as are in our power to- 

 wards checking its career, not only with perfect safety, 

 but with eminent advantage." — ' Treatise,' p. 445. 



In the ' American Agriculturist,' New York, August, 

 1861, Dr. Fitch reasserts that this Eurytoma is the origin 

 of the joint worm, and enumerates four species of the 

 EurytomcB : — 



1. E. hordei, Harris, which has the shanks of all the 

 legs black. 



2. E.fiUvipes, Fitch, Journ. New York State Agr. Soc. 

 ix. 115, with the shanks and thighs tawny yellow. 



3. E. tritici, Fitch, I. c, with the shanks of the fore 

 legs pale yellow and of the others black. 



4. E. secalis, Fitch, n. s. The rye-fly, with the fore 

 and hind shanks pale yellow, and the middle ones black. 

 Very common in Connecticut. 



These insects are described in detail, and their economy 

 given, in Dr. Fitch's ' Seventh Eeport on the Noxious 

 Insects of New York,' pp. 151 — 165. 



In the ' Bulletin de la Societe Imperiale des Naturalistes 

 de Moscow,' 1880, part iii., Prof. K. Lindeman has pub- 

 lished a memoir on the Eurytoma hordei and Cecidomyia 

 ceralis, which had for five years previously proved very 

 injurious in the Kussian State of Mohilev to the rye 

 crops ; and in the 4th part of the same volume of the 

 Moscow Bulletin, Prof. Lindeman has described several 

 Chalcidideous parasites which he had reared from the 

 diseased joints of the rye, as well as a distinct sjDecies of 

 Eurytoma [E. alhinervis), which also resides in the knot- 

 ted joints of the rye. 



Dr. Eatzeburg ('Ichneumonen Forstinsecten,' Bd. i., 



TRANS. ENT. SOC. 1882. PART II. (jULY.) 2 S 



