INJURIOUS INSECTS OF I909Q AND IQIO. 95 
NOTES ON THE ENGLISH GRAIN PLANT LOUSE. 
Macrosiphum granaria, Buck. 
This is the louse which is so common on wheat in Minnesota. 
Specimens of this species were kept under observation during the 
fall of 1908, up to December roth, and as late as this a large num- 
ber of specimens, kept under natural out-door conditions, were still 
found to be alive. No males were found at this time. Only wing- 
less viviparous females were present, and young females in all 
stages; no eggs were found. 
The insects had been kept on winter wheat, and the tempera- 
ture had been down at this time as low as five degrees Fah. below 
zero. These insects were kept on for some time after this, but in 
time succumbed to the cold weather, and all perished. 
On April 5th, 1909, a considerable amount of sod from a field 
of winter rye, which during the late fall of 1908 had been very 
heavily infested all over with Macrosiphum, with the soil for four 
inches below it, was brought into the insectary, and put in a tight 
but airy cage, built for the purpose of stout pieces of wood and 
muslin. It was put near the center of the warm room of the in- 
sectary. This was kept and examined as late as June 30th, and no 
Macrosiphum appeared. 
The material brought in from the rye-field completely covered 
the ground underneath this case, and the fact that the cage was 
3 feet 4 inches wide by 6 feet 5 inches long, showed that a con- 
siderable quantity of sod and soil was brought in. 
While the material in this cage was being so closely watched, 
the rye-field from which the material came was also examined and 
swept from time to time in April; then every few days during May, 
up to as late as the 25th, but no Macrosiphum was found in the 
field until May 29th. On this date Mr. Stafford, by sweeping with 
a fine collecting-net, captured an immature wingless nymph on the 
west side of the rye-field. On May 3ist Mr. Stafford collected 
