THE POTATO 201 



on which they may feed and lay eggs. They are 

 more or less abundant every year and do consid- 

 erable damage to early potatoes. The late crops 

 in Colorado generally escape because most of the 

 adult beetles die off before the potatoes appear 

 above ground. 



"The eggs hatch in from four to eight days, 

 depending on the temperature. The larvae feed 

 at first on the surface of the leaf where they 

 hatch, but soon migrate to the top of the plant 

 and eat the tender young leaves which are just 

 unfolding. The young 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. 



"The best and most practical remedy is spray- 

 ing 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 care- 

 fully 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 

 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 



