28 MISC. PUB. 5 2 6, U. S. DEPT. OF AGRICULTURE 



possibilities. It is a light-brown, or sometimes green, crystalline 

 chemical, which may be used for the control of the Mexican bean 

 beetle and has also given promising results for the control of the 

 codling moth and certain apple diseases, used at the rate of 2 to 4 

 pounds per 100 gallons of spray. It has some possible use against 

 mosquito larvae when diluted with acetone. Also it has given promis- 

 ing results in North Dakota, used as a dust to control the short-nosed 

 cattle louse and the long-nosed cattle louse. 



It has the advantage of being relatively nonpoisonous to higher 

 animals, but it may affect the skin of those handling it. 



PHOSPHORUS PASTE 



Commercial phosphorus pastes are prepared from yellow phos- 

 phorus. Essentially these pastes are made by grinding the yellow 

 phosphorus in the presence of water and then mixing with flour in 

 the proper proportion. Glycerine is sometimes used as an ingredient. 

 Commercial preparations usually contain from 1 to 2 percent of 

 phosphorus. 



Prepared phosphorus paste may be placed on edges of benches or 

 in other places frequented by roaches in greenhouses. It has been 

 recommended for use against the Surinam roach. 



Caution. — Because of its very poisonous nature, phosphorus 

 should be handled with great care. The effects are cumulative, 

 and for this reason phosphorus is more dangerous than some of 

 the more acutely poisonous substances. Since yellow phosphorus 

 is so inflammable and poisonous, it is safer to purchase the com- 

 mercial paste than attempt to prepare it. 



The prepared paste is sold in containers of various sizes. 



POISONED BAITS 



White arsenic (arsenious oxide), sodium arsenite, sodium fluosili- 

 cate, or paris green may be used in making poisoned baits of various 

 types. These materials are discussed separately in this publication. 



One of the commonest baits is poisoned-bran mash. Bran is a 

 well-known byproduct of the wheat milling industry. It is used- in 

 making poisoned bait for the control of cutworms, grasshoppers, 

 crickets, green June bugs, roaches in plant houses, ants, millipedes, 

 sowbugs, and slugs. A commonly used formula is as follows : 



For small For large 



quantities quantities 



Bran 1 quart. 100 pounds. 



Arsenical 1 (see above) 2 teaspoonfuls. 4 pounds. 



Cheap molasses 2 4 tablespoonfuls. 1 gallon. 



Water 1 pint. 7 to 10 gallons. 



1 Recent results have shown that sodium fluosilicate may be substituted for the arsenic 



in this formula and used for the control of grasshoppers, mormon cricket, armyworms, 



and cutworms. It can probably be used to control tbe other pests mentioned herein. 



- Evidence accumulated to date does not show that molasses adds to the attractiveness 



or effectiveness of the bait, and it may be left out of it without loss. 



The bran and arsenical are thoroughly mixed, and the water, con- 

 taining the molasses, is then carefully stirred in. Enough water is 

 used to make the bait thoroughly wet but not enough to drip when 

 squeezed. To control cutworms, it is scattered near the plants in 

 the evening. To control grasshoppers, it is scattered early in the 

 morning. The above formula for small quantities of bait (using 1 



