28 MISC. PUB. 526, 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 poisonous and also highly inflammable, it is safer to purchase 
the commercial paste than to 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 beetle grubs, roaches in plant houses, ants, milli- 
pedes, sowbugs, and slugs. A commonly used formula is as follows: 
For small For large 
quantities quantities 
IB TANS Seer sis Bele ee eee 1 quart. 100 pounds. 
Arsenical* (see above) —--_--__ 2 teaspoonfuls. 4 pounds. 
Cheap molasses *________ ____ 4 tablespoonfuls. 1 gallon. 
Wid Wr cetosaeo oe et ee eee 1 pint. 7 to 10 gallons. 
1 Sodium arsenite solution (32 percent AssOz) is used at the rate of 2 quarts per 100 
pounds of bran. Recent results have shown that sodium fluosilicate may be substituted 
for the arsenical in this formula and used for the control of grasshoppers, Mormon cricket, 
armyworms, and cutworms. It can probably be used to control the other pests mentioned 
herein. It should be used instead of an arsenical in bait for the Mormon cricket. 
2 Hvidence 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 
