99 Farmers’ Bulletin 1282. 
arsenate of lead. This will take care of any beetles which may infest 
the plants after the nicotine has lost its effectiveness. 
OTHER INSECTS. 
Other insects against which this dust has proved entirely satisfac- 
tory on a small scale, but against which no extensive work has been 
done, are the bean aphis,’ the artichoke aphis,’° the rose aphis,'! the 
false chinch bug,” the bean thrips,“* young or immature grasshop- 
pers, and several kinds of hairy caterpillars in their earlier stages. 
Fig. 13.—Large power-operated duster for applying dust to combat onion thrips; rear 
view. 
Very recent tests of this dust against the spotted garden slug * Killed 
100 per cent, even when they were only lightly dusted: 
DISADVANTAGES OF NICOTINE DUST. 
Nicotine dust is by no means a perfect insecticide, being subject 
to the following disadvantages : 
Its volatility causes it to lose strength rapidly, so that unless put 
up in air-tight containers it must be used promptly after manufac- 
ture. 
* Aphis rumicis L. 
W Myzus braggii Gillette. 
u Macrosiphum rosae L. and Aphis rosarum Walk. 
12 Nysius ericae Schill. 
18 Heliothrips fasciatus Perg. 
4 Limar maximus I. 
