266 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



Many growers now prefer to use arsenate of lead at from 3 to 5 

 pounds to the barrel, as there is no danger of burning the foliage 

 with it, and it is much more adhesive. Where Bordeaux mixture 

 is not used the arsenate of lead is much preferable on account of its 

 superior adhesiveness. Where Bordeaux mixture is used, arsenite 

 of lime, or arsenite of lime made with soda, may be used, but these 

 homemade arsenicals should not be used alone, on account of 

 their burning the foliage. 



The vines should be sprayed first when they are a few inches 

 high, and the spraying repeated once or twice at intervals of ten 

 days or two weeks. The larvae are so easily killed by arsenicals 

 that potato growers no longer fear their work, but large quantities 



FIG. 229. The convergent ladybird (Hippodamia convergens): a, adult; 6 

 pupa; c, larva; enlarged. (After Chittenden, U. S. Dept. Agr.) 



of Paris green are wasted by careless application, and by dusting 

 unduly large amounts with poor apparatus, which not infrequently 

 results in burning the foliage. For small areas a bucket or knap- 

 sack pump will be found satisfactory, but for over an acre a barrel 

 pump with a row attachment will prove more economical, and for 

 over ten acres a geared machine spraying several rows at once will 

 be needed. Cleaning up the vines and plowing potato land in the 

 fall after the crop has been harvested will aid in reducing the num- 

 bers of the hibernating beetles. 



Flea-beetles * 



While the potatoes and tomatoes are but a few inches high they 

 are often attacked by myriads of small black beetles, which from 

 * Family Chrysomelidce. 



