CONTROL OF ARGENTINE ANT IN CALIFORNIA. 27 
1918, and has since been used on more than 2,000 acres of citrus. It 
is of thin consistency and greater stability than Formula I. It has 
proved very attractive to ants and has been highly effective in control 
and eradication It was discovered, however, that fermentation of 
this more dilute sirup sometimes occurred, especially in the damper 
sections near the coast. This was corrected by the use of benzoate 
of soda at the rate of 0.1 per cent. 
Preparation of final and most satisfactory formula. — The final form- 
ula was prepared as follows: 
Cost. 
Water 11 pints $0. 000 
Tartaric acid (crystallized) 7 grams 016 
Benzoate of soda 9 grams 029 
Granulated sugar 12 pounds 3. 00 
Honey, strained 2 pounds 77 
Sodium arsenite, C. P f ounce 047 
Total sirup, 2\ gallons. Cost per gallon, $1.54. u 
Put 10 pints of water in a clean vessel over a low fire. When tepid add tartaric 
acid, then benzoate of soda, and then the sugar, slowly, while stirring to prevent 
burning. Measure the depth of the liquid with a stick. Slowly bring it to a boil 
and allow it to simmer for from 30 to 40 minutes. Remove from the stove and add 
water to compensate for evaporation. Stir in the honey before the mixture cools. 
Then add sodium arsenite which has been dissolved in 1 pint of hot water and par- 
tially cooled before being poured into the sirup. Stir thoroughly. 
It is necessary that great care be exercised in the selection of the 
materials used, as well as in the preparation of the sirup. Either 
cane or beet sugar may be used. The sodium arsenite should be 
chemically pure. The honey should be strained and free of comb. 
The sodium arsenite preferably should be dissolved in distilled water 
to avoid the precipitation which sometimes occurs if very hard water 
is used. Vessels should be thoroughly cleaned before being used for 
the preparation of ant sirup, and it is desirable that they be used for 
this purpose only. Oils and various chemicals are distasteful or 
repellent to ants, and sirup which acquires a flavor of such substances 
from the container in which it is prepared or stored may be unattended 
by the ants. The stability of the sirup depends much upon the way 
it is boileo\ If brought to a boil within a few minutes and boiled 
vigorously for 30 minutes the stability appears to be much less than 
if brought to a boil very slowly and then merely allowed to simmer 
for 30 or 40 minutes. Where several times the amount given in the 
formula is made in a large vessel the sirup appears to " stand up 7 ' 
best. This seems due to the fact that the sirup does not come to a 
boil for an hour or longer, and this probably results in greater inver- 
sion. The sirup should be used when fresh. Clean glass bottles are 
best if the sirup is to be stored. 
11 With sugar at present prices (about 10 cents a pound) the cost would be only about 82 cents a gallon. 
