10 ~ BULLETIN 1079, U. S. DEPARTMENT OF AGRICULTURE. 
' Carbolic soap solution: One pint crude carbolic acid added to one gallon soft 
soap, thinned by addition of one gallon of hot water, left to stand overnight, and 
then diluted with eight gallons of soft water (recommended in literature) — 
Pine and ash, sprayed and dipped June 1, were attacked by all types after 
10 days. 
Five per cent solution of nicotine sulphate—Pine, hickory, ash, and juniper 
were sprayed, and all were attacked by type 4 within 10 days. 
Two teaspoonfuls nicotine sulphate dissolved in three ounces of ico and 
added to one and one-half gallons water.—Pine and ash, sprayed and dipped, 
were infested by all types after 15 days. 
Ten per cent solution of sodium carbonate.—Pine and hickory logs sprayed 
were immediately attacked by all types possible. 
Five per cent solution of a proprietary crude cresol-soap disinfectant.—Pine, 
juniper, ash, and hickory were sprayed but were all attacked by all types 
possible. 
A strong suspension of whitewash.—Pine logs dipped were heavily attacked 
after the first rain. 
A strong solution of sodium chlorid.—Pine logs sprayed were immediately 
attacked and their condition was no better than that of the controls. 
One part crude pyridin preparation to ten parts water—This did not mix 
well. Pine and ash were dipped June 1. After 30 days both woods were 
infested by all types possible, but were in somewhat better condition than 
the controls. 
One part crude pyridin preparation to ten parts kerosene—Pine and ash 
were dipped June 1. After 60 days no insects had attacked either wood. 
The odor could still be detected on the logs. This material seems to be very 
promising and deserves further trials. 
REMARKS ON POISONS USED. 
Several of the more active poisons seem to be effective against 
certain types of insects, particularly those of type 1. They are 
especially effective when combined with oils that will penetrate the 
bark (as the mixture of corrosive sublimate and kerosene) or fol- 
lowed by another solution rendering them insoluble (as arsenic acid 
followed by lime water). This latter, however, is difficult to apply. 
They are also more effective when used on absorbent types of bark 
as ash and juniper. 
OTHER EXPERIMENTS WITH INSECTS OF TYPE 3. 
The results of the preceding treatments were not conclusive against 
the ambrosia beetles (type 3) for two reasons: These insects require 
wood that is moist—at least such wood presents optimum condi- 
tions—in which to rear their broods. The logs used in the preced- 
ing experiments, averaging only 6 to 10 inches in diameter, often 
dried so rapidly that they were not suitable for these beetles. At the 
same time another series of experiments was being conducted in 
which water-soaked logs were used. These acted as traps, attract- 
ing most of the ambrosia beetles. 
