73 



THE WHEAT-STEA.W WOEM. 



BY PEOF. G. H. FRENCH. 



(Isosoma Allynii, French.) 



As Mr. John Marten and myself were passing a field of wheat, 

 just before harvest, m the summer of 1880, our attention was 

 attracted by seeing a great many apparently light-heads, some of 

 which were on stalks that were partly dead, though, as a field, the 

 grain was not quite ripe. Upon examination, many of the heads 

 were found only partially filled. Our first thought was that Hessian- 

 flies had caused this deficiency in fruiting, but there were very few 

 signs of them to be found, either then present or having been pres- 

 ent. Upon cutting open the stalks there were found inside one or 

 more small, yellowish worms, and, as these were to be found in 

 more than half of the stalks examined, it was at once concluded 

 that here was the cause. From the examination we were able to 

 give them with our pocket-lenses, we thought they must be the larvae 

 of some dipterous insect, as they were without feet. I took a few 

 pieces of the stalks containing the worms, but Mr. Marten took the 

 most that were taken from the field, as he was at the time one of 

 the assistants in the State Entomologist's office, knowing that rear- 

 ing them to the perfect state would decide to what order of insects 

 they belonged. As my time was fully occupied with other matters, 

 the portion took by me received but little attention, and as a con- 

 sequence they dried up, instead of producing the perfect insects. 

 Mr. Marten collected more of the stalks afterwards, and, after keep- 

 ing them for a time, found a single green fly in the jar containing 

 the stalks, that had evidently come from the samples, though I do 

 not know that the pupa case from which it was hatched was found. 

 The fly was thought be a species of Chlorops, though what species 

 was not determined, and indeed cannot be well now, for the speci- 

 men was accidentally destroyed, though it might approximately be 

 identified from the description that was taken. No other specimens 

 were obtained. 



Dr. Thomas referred to this in the Prairie Farmer of August 

 28th, 1880, giving Mr. Marten's description of the insect reared, an 

 account of where larvae were found in the wheat, and a general 

 account, by way of comparison, of the manner in which species of 

 Chlorops were known to work in Europe — the title of the article 

 being "A new enemy to wheat." As only one specimen was obtained, 



