THE POTATO 203 



this way. Their greatest damage to potatoes in 

 Colorado is done by the larvae, which live under 

 ground. These larvae are tiny white grubs which 

 attain a length of about a quarter of an inch. The 

 first brood is to be found during June or early July. 

 They frequently cut into and destroy the young 

 tuber stems of the potatoes, thus preventing a reg- 

 ular setting of the crop. The second brood of 

 larvae appear during August and September. This 

 brood bores into the fl^sh and under the skin of the 

 potatoes, causing a pimply or scabby development, 

 which may cause great waste in preparing the tu- 

 bers for the table and seriously depreciate their 

 market value. 



''No satisfactory remedy for this pest is known. 

 The leaf injuries to young potatoes and tomatoes 

 may be largely avoided by spraying the leaves 

 thoroughly with Bordeaux mixture to which Paris 

 green is often added. The insects appear to avoid 

 the parts of the plant covered with these disagree- 

 able substances and to seek fresh tissues upon 

 which to feed. It is not certain where the insects 

 hibernate, but they are found often in the fall in 

 large numbers feeding on stray potato plants or 

 pieces of tubers which have been left in the fields. 

 It is well to clear up the fields immediately after 

 the crop is gathered. These insects are seldom, if 

 ever, found on new ground, and are much worse 

 where potatoes are planted in succession." 



GRASSHOPPERS 



Grasshoppers are not often counted as an insect 

 enemy of the potato, but their ravages in eastern 

 Colorado have been such that growers have lost 

 heavily. S. Arthur Johnson in "Bulletin 175" of 



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