24 
Journal of Agricultural Research 
Vol. II, No. i 
HIBERNATION 
The first freezes in autumn killed the adults in the rearing cages at 
La Fayette, Ind., in 1912. Any larvae that happened still to be feeding 
were killed also. This indicates very strongly that the species does not 
hibernate in either the adult or larval stage. It appears, then, that in 
the latitude of La Fayette, Ind,, at least, it passes the winter in the 
puparium only. 
EIRE HISTORY OR AGROMYZA PARVICORNIS IN FLORIDA 
Mr. G. G. Ainslie made observations on this miner from November, 
1912, to the middle of April, 1913, at Lakeland and Orlando, Fla. 
Special plantings of com were made in the field, and volunteer plants and 
regular plantings were also kept under observation. 
SEASONAL OCCURRENCE OF LARVAE 
On November 26, 1912, larvae were found to be quite plentiful in 
volunteer corn that was about 10 to 12 inches high. This com was kept 
under observation, and it was found that the miners bred slowly here 
throughout the winter. No killing frosts occurred during this time. 
There were three dates during this period at which the larvae were the 
most abundant—viz, February 4, March 5, and March 27. 
PERIOD OF INCUBATION OF EGGS 
Of 19 eggs that were deposited in confinement during March, 2 hatched 
in 6 days and 17 in 7, while some that were found in the field did not 
hatch for 8 days, the average being 6.5 days. 
LENGTH OF LARVAL STAGE 
Accurate observations were made on 13 larvae during the latter part 
of February and to the middle of March. It was found that the period 
from hatching until they left the mine varied from 6 to 12 days, the 
average for the 13 being 7.9 days. The larvae in Florida, as well as far¬ 
ther north, invariably leave the mines to pupate. 
LENGTH OF PUPAL STAGE 
Table I gives most of the available data on the length of the pupal 
stage for Florida. 
It will be noted that the larval stage was longer in Florida than given 
for Indiana. Larvae that hatched late in Indiana were overtaken by 
frosts, while the rearings in Florida continued through cool weather 
without being interfered with by frosts. 
The same interesting phenomenon occurred here that was observed in 
Indiana—namely, that apparently healthy living pupae went into hiberna¬ 
tion at a time when the miner was found breeding freely in the same 
