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THE BEET LEAF-BEETLE. 19 
Flocks of blackbirds frequently congregate in fields of beets which 
are strongly infested by the beet leaf-beetles. August 17, two such 
birds were shot, but their crops were found to contain nothing ex- 
cept vegetable matter. No noticeable reduction in the number of 
the beetles could be observed during times when blackbirds fre- 
quented the fields, and it may be concluded that they do not nor- 
mally feed on these insects. 
OTHER CHECKS. 
Occasionally cattle or horses are turned on to areas where the 
beetles are in hibernation, and a few beetles may be trampled upon 
and killed, but as a rule few are destroyed in this way. 
Ordinarily this insect is not greatly affected by climatic condi- 
tions. Remarkably few hibernating beetles die during the winter. 
During January of one year a low spot upon which many beetles 
were in hibernation was flooded to a depth of 3 or 4 inches by 
melting snow. The majority of the beetles saved themselves by 
climbing up the grass stems above the water. On this area there 
were a few tufts of grass which were covered with a crust of snow, 
and here the beetles were trapped under the crust, and were 
drowned; but this case of winter killing is exceptional, and usually 
the beetles are uninjured by rain, snow, or cold. 
Some of the eggs which are deposited early in the spring, when 
the nights are still frosty, become cracked and fail to hatch. Pos- 
sibly this is caused by the cold, as no cracked eggs have been found 
during warm weather. In early spring young larve are occasion- 
ally knocked from their food plants, and killed by the cold dashing 
rains, but the number destroyed in this way is usually very small. 
EXPERIMENTS WITH INSECTICIDES. 
The following insecticides were tested against the beet leaf-beetle 
at Rocky Ford, Colo.: 
Spraying experiments. 
No. 1. Paris green, 1 pound to 50 gallons of water. 
No. 2. Paris green, 1 pound, and whale-oil soap, 3 pounds, to 50 
gallons, ; 
No. 3. Paris green, 1 pound, and rosin-fish-oil soap, 3 pounds, to 50 
gallons. 
No. 4. Paris green, 1 pound, and laundry soap, 2 pounds, to 50 
gallons. . 
No. 5. Paris green, 1 pound, and lime, 1 pound, to 50 gallons. 
No. 6. Paris green, 14 pounds to 50 gallons. 
No. 7. Paris green, 14 pounds, and whale-oil soap, 3 pounds, to 50 
gallons. 
No. 8. Paris green, 14 pounds, and whale-oil soap, 3 pounds, to 50 
gallons. 
