EXPERIMENT STATION WORK WITH INSECTICIDES. 



273 



treated with Paris green and arsenate of lead were tested for arsenic 

 and found to be entirely free. Proprietary insecticides were found 

 not to have any fertilizing value, as has been claimed. In Missis- 

 sippi " arsenate of lead was applied to potatoes at the rate of 4 pounds 

 per 50 gallons of water. The beetles were effectively checked by one 

 application, and the arsenate of lead appeared to be more satisfactory 



than Paris green. 



THE POTATO WORM. 



The potato worm is a serious enemy of the potato in California, and 

 methods of controlling this pest in potatoes were tested at the Cali- 

 fornia Station.'' In order to control the potato worm it is recom- 

 mended that the wild nightshades be destroyed in the neighborhood 

 of potato fields and that lantern traps be used in such fields. It is 

 desirable to go over potato fields and cut out infested stalks as they 

 appear. Compact hilling of the potatoes is found to prevent infes- 

 tation of the tubers to a considerable extent. As soon as potato 

 tubers are dug they should be removed from the field, in order to 

 avoid exposure to infestation, and all rubbish should be destroyed 

 after harvesting. If stored potatoes become infested the moth may 

 be effectively destroyed by using carbon bisulphid at the rate of 1^ 

 pounds per 1,000 cubic feet of space. 



THE PEACH BORER. 



The peach borer has been studied at so many of the stations and 

 referred to in so many bulletins that only a few of the results ob- 

 tained can be mentioned in this connection. In New York '^ a series 

 of experiments was carried on to test various methods recommended 

 for the control of the peach borer, especially those which Avere used 

 successfully at the Missouri Station. In Missouri coal-tar a])i)li- 

 cations to the trunks of the trees and the use of thin wooden 

 wrappers were carefully tested. These methods were tried further 

 in New York. The coal tar obtained from Missouri was not as 

 thick as the ordinary product in New York and was quite easiW 

 applied with a brush. Wire nettings and wooden wrappers were also 

 placed al)out a number of the trees. The gas tar obtained from Mis- 

 souri ke})t out the borers quite effectively and did not injure the 

 trees. The wire-cage protectors, however, appeared to be somewhat 

 ineffective, while the wooden wrappers gave excellent results. In 

 South Carolina ^ it was found important to use a good wash in connec- 

 tion with the ordinary worming process. Where worming was done in 

 the fall many small borers failed to be detected, and since at this time 



"Mississippi Sta. Bnl. SI. 

 f'Califoniia Sta. liiil. i:!.'). 



" New Yorl< Cornoll Stn. Bill. 192. 

 rfSoutli Cai-oHuii Sta. IJul. m. 



II. Doe. 924. 59-1- 



-18 



