INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 35 
very dilute form. It is used chiefly as a poison in cutworm, mole 
cricket, or grasshopper bait. 
Caution.—Sodium fluosilicate is a strong poison and should be 
kept away from food. 
SULFUR 
Sulfur (S), a native element, is an important fungicide and insecti- 
cide, as well as a useful adjunct or carrier in many dust mixtures. It 
comes in several forms for insecticidal uses—as a finely ground 
powder; as a powder plus a wetting agent, called wetable sulfur; 
and as flotation paste (see also Liquid Lime-Sulfur and Dry Lime- 
Sulfur, p. 17). Much progress has been made in grinding sulfur, so 
now it is almost universally available in such fineness that almost all 
of it will pass through a number 325 sieve. The most finely divided 
material available at low cost is the flotation sulfur paste, which is 
almost colloidal and sticks well to foliage. Sulfur is used for the con- 
trol of the potato leafhopper (on bean, aster, and dahlia), the cotton 
_ flea hopper, the tomato psyllid, red spiders, the phlox plant bug, the 
tarnished plant bug, and the broad mite. As a diluent for dusts it 
is often used with lead arsenate, pyrethrum powder, ground rotenone- 
containing roots, or other materials. (See Oil Dusts, p.26.) A fungi- 
cide-insecticide dust to control black spot and rose slugs on roses 
comprises lead arsenate 1 pound, tobacco dust 1 pound, and sulfur 8 
pounds. Flowers of sulfur prepared by sublimation, being too coarse, 
are not used for dusting plants but may be used by burning to fumi- 
gate mushroom houses and greenhouses between crops. 
When sulfur is used on fruit trees it should not be followed by oil 
sprays before all sulfur residues have disappeared. Oil and sulfur 
may cause severe foliage injury. 
Caution.—In using sulfur, especially when applying or han- 
dling it as a dust, care should be taken to prevent getting it into 
the eyes. If the eyes are affected, do not rubthem. It is well to 
wear goggles and a respirator. 
STYRENE DIBROMIDE 
Styrene dibromide is a colorless, crystalline chemical having a mild 
naphthalenelike odor. It is soluble in and imparts no color to mineral 
oul and may be used, at the rate of 1 gram dissolved in 100 cubic centi- 
meters of highly refined white mineral oil, as a satisfactory substitute 
for pyrethrins in corn earworm oil. (See Pyrethrum, or Insect Pow- 
der, pp. 29-30.) 
TAR DISTILLATE 
Coal-tar distillates, commonly called tar oils, have been used as 
dormant sprays for the control of aphids, the eye-spotted budmoth, 
and the oystershell scale on apple. These preparations are emulsified 
so they can be mixed with water. They are also sometimes sold in 
combination with dormant mineral oil. 
Since they must be combined with mineral oil for the control of the 
San Jose scale, are caustic to the skin of spray men, and are likely 
