16 BULLETIN 902, U. S. DEPARTMENT OF AGRICULTURE. 
Experiment Xo. 6.— April 29. 1912. 
Arsenate of lead, paste pound . . 1 
Whale-oil soap do 1 
Nicotine sulphate ounces. . 5 
Water gallons. . 10 
This was applied to young mustard plants which were so small 
that only the upper side was treated. In this case the beetles were 
apparently dead but after being confined in a cage revived withhi an 
hour. The following day the plants showed an even coating of 
arsenate on the upper surface and were almost entirely free from the 
beetles. Some of the worse pitted leaves had died, became very dry, 
and crumbled when touched, but this was due to the attack of the 
beetles and not to the insecticides. This plat was examined at 
intervals, and a week later the plants were growing excellently. As 
the beetles began increasing in numbers an additional spraying was 
necessary. 
Experiment Xo. 7. — April 29, 1912. 
Arsenate of lead, paste pound . . 1 
Whale-oil soap do 1 
Water gallons. . 10 
As in the previous experiment, the upper surface only was sprayed, 
radish and mustard being the plants treated. In this instance the 
infestation was so severe that many of the plants were so nearly 
destroyed that they failed to recover, partly because of hot. dry, and 
windy weather. It was only where the leaves were almost entirely 
consumed by the beetles that the plants died. The coating of arsenate 
was excellent and four days later the plants were growing well and 
were almost free from flea-beetles. 
Experiment Xo. S. — May 9. 1912. 
The same formula as Xo. 7. applied to the same plants. Rain 
intervened for several days but nine days later the plants were 
described as growing beautifully and only moderately infested by 
flea-beetles, being beyond danger of injury. Although no dead 
beetles were found, the experiment was a success and the radishes 
were being sold at the time. 
Experiment Xo. 9. — April 29. 1912. 
A badly infested plat of mustard was dusted with dry Paris green 
inclosed in a cheesecloth sack, but there was a moderate wind and a 
considerable portion of the poison was blown away. The next day, 
however, although the plants were free from beetles they were nearly 
dead. Those which remained alive and were growing were practi- 
cally free from flea-beetle attack. 
Experiment Xo. 10.— May 2, 1912. 
Arsenate of lead, paste pound . . 1 
Whale-oil soap do 1 
Water gallons. . 10 
