74 



and as there were plenty of larvae to be found in the fields long after 

 the grain was cut, some doubt was entertained as to the relation of 

 the fly hatched to the general mass of larvae, especially as it was 

 known that the larvae of insects belonging to at least three of the 

 orders of insects —Hymenoptera, Lepidoptera and Diptera — at times 

 were to be found in wheat-stalks. It was to settle this uncertainty 

 that I decided to try to rear the perfect insects, if they should be 

 found in the wheat this year, 188i. 



An examination of the stalks this year, just before harvest, showed 

 that they were fully as numerous as they were last ; and I can, per- 

 haps, do no better than to give some dates and conditions of insects 

 as. I find them in my note-book. The first specimens were taken 

 June 15th, the wheat nearly ready for harvest. A more careful exam- 

 ination, with the aid of a low-power object-glass in the compound 

 microscope, revealed the fact that, though the larvae were footless, 

 there were minute processes along the sides, that were thrust out at 

 pleasure, and that it had a distinct transverse head armed with two 

 distinct brown jaws. From this I thought them hymenopterous 

 instead of dipterous larvae. 



June 30th, more specimens were taken from the fields, mostly from 

 stalks left standing in harvesting, though some from the stubble ; 

 also found a fly in the jar containing the first lot of specimens, and, 

 upon search, the pupa-case in the stalk from which it hatched. 

 This was quite different from the fly obtained by Mr. Marten last 

 summer, of a different color and much larger. It was evident that 

 this was not the imago of one of the yellowish larvae, of which I 

 had so many. I may say that about this time Miss Nettie Middle- 

 ton found a fly in stalks she had, which I suppose to be the same, 

 but have not seen it. 



July 8th, found two hymenopterous insects hatched in the jar con- 

 taining the first specimens, but they were evidently the parasites of 

 Hessian-flies, as a stalk containing two pupae of that insect was 

 placed in the jar. The insects inside the stalks were at that time 

 still larvae, as far as examined. 



July 20th, a hymenopterous insect was found in the second lot of 

 stalks, and there was no doubt but that it came from one of them. 

 Upon going to the field I found one hatched, still inside the stalk, 

 but in the act of gnawing out. Besides this I found several pupae 

 and larvae in the stalks, the proportion of those found that day that 

 had changed to pupae being about one-fourth of all found, the three- 

 fourths being still larvae. After this, I have dates of finding them 

 hatched, both in the house and in the field, up to August 20th, demon- 

 strating apparently that the insect that had done the damage was 

 no other than the small four-winged flies. 



On August 20th, out of 20 infested stalks taken at random in the 

 field in a place skipped in reaping, 8 had hatched and gnawed out, 

 4 were still larvae, ;5 were changed to chrysalids, 5 were dead and '6 

 were hatched, had partially gnawed through the stalk, but had not 

 made their escape. 



