NOTES ON THE YELLOW-BEAR CATERPILLAR. 63 
hyacinth, dahlia, cherry, gooseberry, blackberry, raspberry, currant, 
grape, dock (Rumex), Amaranthus, Chenopodium, Helianthus, 
Solarium rostratum, Verbesina, Ambrosia, Russian thistle (Salsola 
tragus Auct.), and Spanish needle. 
EXPERIMENTS WITH ARSENICALS. 
Opportunity was afforded for testing arsenate of lead and Paris 
green as means of suppressing the yellow-bear caterpillar on sugar 
beets and celery. 
Experiments were made as follows: 
Experiment No. 1. — Arsenate of lead applied at the rate of 6 pounds 
in 100 gallons of water. 
Experiment No. 2. — Arsenate of lead at the rate of 8 pounds in 100 
gallons of water. 
Experiment No. 3. — Arsenate of lead at the rate of 10 pounds in 
100 gallons of water. 
Experiment No. 4- — Arsenate of lead, 8 pounds to 100 gallons, 
applied twice to the same plants, practically equaling 16 pounds of the 
arsenate to 100 gallons of water. 
In these experiments 150 gallons of the mixture at the various 
strengths were applied September 7-9, 1909, to 3 acres of sugar beets 
with an ordinary barrel sprayer, mounted on a cart and drawn by a 
mule. The sprayer was fitted with an 8-row attachment and nozzles 
of the Vermorel type, and the upper surface of the beet foliage was 
given an even coating of poison. Traces of the poison were visible 
on the sprayed foliage for nearly a month after application. 
These four experiments were entirely unsuccessful, as practically 
no larvae were killed either in the field or in cages supplied with 
poison-coated leaves. In both cases the poisoned foliage was eaten 
readily. A sample of the arsenate of lead used in the experiments 
was analyzed by the Bureau of Chemistry and found to be of unusu- 
ally good quality. 
Experiment No. 5. — Arsenate of lead (Disparene) at the rate of 8 
pounds in 100 gallons of water. 
September 21, 6 gallons were applied with a small compressed-air 
sprayer fitted with a nozzle of the Mistry type to 8 rows of celery, 
each about 90 yards in length. A very thorough and even coat of 
poison was given the plants, but very few larvae were killed. 
An analysis made of this arsenate of lead by the Bureau of Chemis- 
try showed that it was of unusually good quality. 
Experiment No. 6. — Paris green, 5 pounds, and lime, 5 pounds, to 
each 100 gallons of water. 
September 25, 2 gallons of this mixture were applied with a 
compressed-air sprayer and nozzle of the Mistry type to 2 rows of 
celery, each about 90 yards in length. Twenty-four hours after the 
