Bulletin 151, Truck and Garden Insects


 SOAP.-Any strong alkaline laundry soap is a good insecti-
 cide. (Before the recent advance in the price of potash, whale-
 oil or fish-oil soap was the cheapest.) The higher priced, more
 nearly neutral toilet soaps are not as good because the free
 alkali of the cheaper soaps is needed to kill the insects. One
 pound of soap to 8 gallons of soft water will kill most small,
 soft-bodied insects. If more soap is added, the killing power
 of the solution is increased but little, and if more than 8 pounds
 to 50 gallons of water is used the killing power is actually de-
 creased. If less than 6 pounds to 50 gallons is used, the killing
 power is also decreased. If the water is hard more soap will be
 needed as some of it is used in softening the water.
 PYRETHRUM OR PERSIAN INSECT POWDER.-Pyrethrum is
 much used against household insects. It is too expensive for
 general use in garden and truck farms. It rapidly loses its
 strength when exposed to the air.
 BORDEAUX.-Bordeaux mixture, the common fungicide, is
used to repel such insects as flea-beetles. But its chief interest
with regard to insect control, lies in the fact that it can be com-
bined with most arsenicals. This makes a spray that will kill
both fungi and biting insects. Tobacco can also be mixed with
bordeaux to kill sucking insects. In mixing these insecticides
with bordeaux, let the bordeaux solution take the place of the
water called for in the formula.
 The following directions for preparing bordeaux mixture
are given by the plant pathologist of the Station:
 Bordeaux mixture is made from bluestone (copper sulphate), rock lime,
and water. If much spraying is to be done, make stock solutions of the
bluestone and lime; from these, bordeaux mixture of any strength can be
made.
 To make these stock solutions, take a barrel which holds 50 gallons of
water; suspend 50 pounds of bluestone in a gunny sack or cheese cloth at
the top of the water so that half of the bluestone is below water. After
it is all dissolved there will be one pound of bluestone to every gallon of
the solution. Place 50 pounds of good rock lime in another barrel and
slake it. Then add water until there are 50 gallons of the lime water.
 Bordeaux mixture is used in different strengths, according to the
season of the year and the kind of plants to be sprayed. A 5-5-50 bor-
deaux mixture means a mixture containing 5 pounds of bluestone, 5 pounds
of lime, and 50 gallons of water. In all formulae of bordeaux mixture, the
first figure refers to the number of pounds of bluestone, the second figure
to the number of pounds of lime to be used, and the third to the number
of gallons of water.
 To prepare the 5-5-50 mixture, two more barrels of 50 gallons capacity
each are needed. In one barrel put 40 gallons of water and 10 gallons of
the bluestone solution. In the second barrel put 40 gallons of water and
10 gallons of the lime water. Take equal parts from each of the two
barrels containing the dilute solutions and pour them simultaneously into a
spraying machine. These mixtures should be poured thru a very fine
sieve or cheese cloth to keep the larger particles from entering the ma-