The Potato Industry oe Colorado. 43 
reach full growth about three weeks later. Soon eggs are laid again 
and the second generation hatches. Ordinarily two broods are all 
that we may expect. 
Remedies. —The best and most practical remedy is spraying 
with some arsenical poison. In commercial fields the best machine 
is a power sprayer drawn by horses. In garden patches a hand 
sprayer does very good work. Arsenate of lead, altogether the best 
poison, is a white paste which must be carefully mixed in a little 
water before it is poured into the spray machine. It should be 
strained through a fine screen in order to remove all lumps which 
might clog the nozzles. Apply the poison at the rate of six or eight 
pounds to a hundred gallons of water. The proper time to spray 
is when the young grubs begin to appear at the tops of the stems. 
Arsenate of lead does not kill as quickly as Paris green, but it 
sticks to the leaves much longer and the benefits can be seen for 
weeks even after rains. Paris green is the old standby, is cheaper 
for a single application, and is still the most used. This poison is 
mixed with water at the rate of a pound to seventy-five or one 
hundred gallons. There is danger that this substance will burn 
the foliage of the potato, and to avoid this, it is well to add the 
milk from two pounds of slaked lime to each hundred gallons of 
water used. While spraying either of these poisons the contents of 
the spray machine should be kept well agitated. Sometimes the 
pest is confined to small areas. In such cases the insects are often 
controlled by the use of dust sprayers, which either blow the Paris 
green out in fine clouds, or dust out the same poison when it has 
been mixed with flour or carefully screened air slaked lime.* 
THE potato ELEA BEETLE, (Bpitrix cncumeris.) 
The Insect. —When tomatoes are first set out or potatoes first 
come up there may often be found on them tiny black beetles which 
jump when alarmed. They are called the flea beetles because of 
this habit, though they are not closely related to the flea. 
Injuries. —The adult insects live over winter and appear during 
the latter part of May and first of June. They get their living by 
eating tiny holes in the surface of the leaves of plants of the potato 
family, and often attack cucumbers and beans. The insects very 
often congregate in such numbers that the leaves of the plants 
appear almost black with them. Newly set tomato plants and young 
potatotes frequently have their leaves so badly eaten that they 
*The suddenness of scourges of potato beetles should be remembered. 
At Greeley, they had not been very serious for many years, but in 190 9 
$50,000 was spent in fighting them. In 1910, everybody was ready with 
poisons and sprayers, and almost no beetles appeared. These beetles are 
liable to be serious in districts where growers have not noticed any harm 
from them. The first beetle seen should be a warning to be ready the 
next year.—C. L. F. 
