64 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
treatment 15 per cent of the larvee were dead, and within three or 
four days few larve remained on the plants. The disappearance 
of the larva was not entirely due to the Paris green, as the celery was 
sprayed, at about the same time the poison was applied, with a solu- 
tion of lye-sulphur for the common red spider (Tetranychus bimacula- 
tus Harv.). This solution was evidently very distasteful to the 
larvee and they went over to the unsprayed or check plants. 
Experiment No. 7.—Paris green, 8 pounds, and lime, 8 pounds, to 
100 gallons of water. 
September 1 about 40 gallons of this mixture were applied to 1 
acre of sugar beets with the same equipment used in Experiments 
Nos. 1, 2, 3, and 4. Some trouble was experienced in keeping this 
mixture in suspension, but a fairly even coat of poison was made, 
which remained visible for at least ten days after the treatment. 
This application was ineffective, for although a few partly grown 
larve were killed the number was so small that a week later the 
larvee were as abundant on the sprayed plants as on those unsprayed. 
Analysis made of a sample of the Paris green used in this experiment 
showed it to be of good quality. 
Experiment No. 8.—Paris green, 10 pounds, and lime, 10 pounds, in 
100 gallons of water. On September 12, 65 gallons of this mixture 
were applied with a compressed air sprayer and Mistry type nozzle 
to 5 rows of celery, each row being 100 yards in length. Although 
the mixture required frequent agitation to hold the poison in suspen- 
sion, an even coat of poison was applied. 
Twenty-four hours after the application 55 per cent of the larve 
were dead, and three days later but few living individuals could be 
found on the sprayed plants, while on the check row they were still 
abundant. This treatment was extremely effective, as practically 
100 per cent of the larve were killed. 
Experiment No. 9.—Paris green, 10 pounds, and lime, 10 pounds, to 
100 gallons of water. On September 21, 9 gallons of this mixture 
were applied to 10 rows of celery, each row being about 90 yards in 
length. This experiment was a repetition of No. 8, and the results 
were practically the same. 
Experiment No. 10.—Paris green, 10 pounds, and 10 pounds of 
lime to 100 gallons of water. On September 14 about 35 gallons of 
this mixture were applied to a little over half an acre of sugar beets. 
An ordinary barrel sprayer mounted on a handcart was used. The 
sprayer was fitted with an agitator so small that it was impossible 
to keep the poison in suspension. As a result the bulk of the poison 
was applied to the first few rows of beets sprayed. Owing to rain of 
the previous day the soil was so moist in the beet field that the pump 
could not be taken into it, and the mixture had to be applied through 
a 50-foot length of heavy garden hose and a nozzle of the Vermorel 
—S 
