veloped in that field. These coming ont among the yonng wheat 
found immediate opportunity for oviposition, and, following the 
usual habit of the species, proceeded to breed without delay. 
Here _ at Edgewood, consequently, we had a practically isolated 
experiment, not interfered with by invasion from without. At 
Billett Station, however, the fly was common enough throughout 
the country surrounding to do noticeable damage to fields not far 
away, and there, doubtless, the repeated entrance of outside ima¬ 
gos searching the country for growing wdieat, lengthened out the 
time of oviposition and the development of the brood. 
The isolation of the field at Edgewood gives us this further 
valuable information. It will be remembered that the larvae col¬ 
lected there September 22, first formed the puparia on the 2d 
October, and gave the first imagos on the 18th of that month. 
Now, November 16, we found in this field an abundance of larvae 
and puparia, most of the latter freshly formed,—necessarily de¬ 
scended, therefore, from the imagos resulting from the first brood 
of larvae developed in this plot. We have here, additional and 
conclusive proof that the time required for the development of a 
brood from the appearance of the puparia of one generation (Oc¬ 
tober 2) to those of the next (November 16) is, at that season of 
the year, about six weeks. 
To the above record of observations for the experimental plots 
I need only add that a visit made November 23 to wheat fields 
near Albion, Illinois, revealed the same state of affairs with re¬ 
spect to the fly as occurred in these special cultures, about ten per 
cent, of the examples found being puparia, and the remainder 
naked larvte, mostly full-grown. Both these latest observations at 
Edgewood and Albion were made during a period of severe frost 
and falling snow; and they consequently show beyond question 
the hibernation of the fly, in large part, as naked larvae. This 
item in the history of the insect has been previously reported 
only by Mr. John Marten, of Albion, whose observations were 
printed in the “Fruit Growers’ ” Journal of Cobden, Illinois. I have 
not seen the article, but Mr. Marten kindly furnished me, March 
22, 1886, the following abstract of it, so far as it relates to this 
subject: 
“Beginning in October, 1883, my observations extended to near 
the middle of March 1884, during which time I examined several 
hundred of the larvae. Many of them had not, up to the end of 
February, formed the puparia, or outer hardened skins, in which 
they usually pass the winter and undergo their final transforma¬ 
tions. This, so far as I can learn, is a new feature in the habits 
of the fly; and it is exceptionally strange at that time, as during 
the period of observation we had a temperature of from 26° to 
30 below zero, with intervals in which the fields were quite free 
from snow. This change (the forming of puparia) began to take 
place as early as October, 1883, but was not so marked in some 
fields as in others. The unchanged lamu were found in two 
fields through January, 1884, and in one field which was well pro- 
