42 
to dislodge but not destroy them. Pure powder applied with a bellows 
quickly dislodged them, but did not kill over 10 per cent. Those not 
killed soon recovered and crawled back upon the plant. 
On Potato Beetle. 
Used in the field pure it destroyed about 50 per cent, of the larvae, 
jmncipally younger ones. Adults were not injured though heavily 
treated, but when confined in breeding cage and thoroughly dusted 
they were all killed. I am quite sure pyrethrum is not a satisfactory 
remedy for Potato Beetle where London purple or Paris green can be 
used with safety. 
On Tomato Worms. 
Several species of Sphingids were quite numerous on the tomato 
vines, principally quinque-maculata. On these the powder was used 
pure and also diluted three times. I did not observe an instance where 
thoroughly applied that it did not produce death in from two to three 
days. 
On Squash Bugs. 
Diabrotica vittata and also 1 2-punctata were treated with the powder 
both pure and diluted three times. It destroyed them very effectually, 
although I am not certain that they could be so successfully treated in 
the spring when the plants are small and the beetles very active. This 
treatment was late in the season when they were feeding on pollen in 
the bloom of squashes. 
On Fall Web worm. 
Not enough of these could be found for thorough tests, but pure 
powder used on one colony made them immediately break from the 
web, fall to the ground, and scatter in all directions, but two days’ ob- 
servation failed to show any dead ones. 
Several times woolly caterpillars were treated both with powder and 
solution without in any instance producing death. 
The powder used throughout was the roseum , and from one package. 
Buhach ( Pyrethrum cineraricefolium). 
I was ordered to obtain this powder direct from dealers, and finally 
sent to Stockton, Cal., for it. It did not arrive in time for full com- 
parisons with P. roseum , but I tested it quite thoroughly on P. brassicce. 
Used in minute particles it kills in one to three hours, was decidedly 
slower in action than P. roseum , but the weather was cooler. Exposed 
on leaves of plants it killed up to three days’ exposure though very slow 
at last trial. Weather cool as before mentioned. 
Diluted with flour it kills in small jars up to 30 dilutions, but iu 
cages was not effective after 10 dilutions, and I think most of these 
