68 
injured the later sown plats, so that at harvest, July 5, these latter 
were the poorest of all, the other three averaging about alike. All of 
these plats during both years had been sown in narrow strips among 
corn along one side, the remainder of the field being corn, and later 
also sown to wheat, thus bringing the latest-sown plats between those 
sown earliest and the entire field itself, as appeared to me, the severest 
test to which I could subject the several plats. The results, while not 
conclusive or even entirely satisfactory, indicate that in that latitude 
about September 25 is, generally speaking, a good time to sow wheat 
to escape fall attacks of the fly and winter killing. A series of plats 
sown for me by Mr. Miles Martin, of Marshall, Parke County, Ind., in 
very near the same latitude as Richmond, but nearer the western border 
of the State, gave rather more conclusive results, the sowings of Sep- 
tember 22 being almost entirely exempt from the attack of the Hessian 
fly, while earlier plats were infested. 
In regard to my own experiments here on the Experiment Station 
grounds at Lafayette, 1 may state that I have never been able to pro- 
voke a disastrous attack of the pest, though there has been nothing left 
undone which could possibly induce the adult flies to oviposit at any 
time between March and December; and there is probably not a month 
between these dates during which the insect could not have been found 
in all of its stages. The two destructive broods, however, invariably 
appear in May and September; in the latter case usually before the 
20th. 
My own experimental showings were rather more elaborate and ex- 
tensive than those of any of my correspondents, comprising a number 
of varieties and extending over several months. Without going into 
details, the experiments and results may be summarized as follows: 
1887, plats comprising the varieties Michigan Amber, Clawson and 
Velvet Chaff, each one width of a grain drill twenty rods in length, were 
sown on the following dates: August 13, 27; September 10, 24; Octo- 
ber 8, 27; November 5,19. The autumn was very dry, and the plants 
of the first six plats went into winter in poor condition, being very 
small, while the last two sowings did not come up until the following 
spring. The severe winter destroyed the plants so generally, that only 
the first three produced sufiicient grain to pay for harvesting. These 
were also the only ones to suffer from the fall.attack of the fly, the first 
producing adults October 1. Plat 8 was attacked on the following June, 
and on the 26th was badly infested with young larve, full-grown larvee 
and puparia, the latter, the most numerous, were found on the 16th of 
July. The plats harvested produced a poor crop, but the Michigan 
Amber ranked first, Velvet Chaff second, and Clawson the poorest of all. 
ery 
