SUMMARY OF RESULTS. 81 
gram per cubic foot and with exposures of one hour, three hours, and 
overnight, all scales were uniformly killed. The holding of fruit in 
a warm room for a couple of days previous to examination resulted 
in a marked discoloration of the dead insects, leaving no doubt as 
to their condition. 
Variety-of-fruit series (Table VI)—Numerous varieties of apples, 
including the principal commercial sorts, fumigated for one hour and 
using potassium cyanid at the rate of 0.30 and 0.50 gram per cubic 
foot, were not in any way injured. 
Rhode-Island-Greening-unjury serves (Table VIT).—The only variety 
of apple used in the tests showing gas injury was the Rhode Island 
Greening from western New York. Other fruit of this variety of 
unknown source was not injured by an excessive strength of the gas. 
No strength of gas or period of exposures was determined which was 
not injurious to western New York Greenings. Injury was more 
pronounced on fruit subjected to a long exposure than when a heavier 
dose and shorter exposure were given. 
Fumigation of dry, moist, and wet fruit (Table VITI).—Observations 
made at different times on fruit fumigated in a dry, moist, and wet 
condition showed that its condition in this respect was immaterial. 
Apples thoroughly wet by applying water with a spray pump were 
not in the least injured, and all scales were killed. 
Cold-storage serves (Table LX ).—Fumigation of scale-infested apples 
in a local cold-storage plant with the temperature 30° F. showed that 
adequate diffusion of the gas occurred, killing all of the scale insects, 
and without injury to the fruit. 
Mortality of scales on frurt during winter (Tables IT and X I).—Data 
obtained at different times on condition of scales on untreated fruit 
for comparison with their condition on fumigated fruit showed, as 
occurs normally out of doors, that the very young and old scales die, 
the survivors being mostly those about one-third grown. In the case 
of fruit held in storage in 1907-8, until March 3, only about 9.5 per 
cent of scales present were alive, and these were exclusively about 
one-third grown. In 1906-7 the percentage of live scales present on 
Baldwin apples, on the 12th of November, 55.90, dropped by Decem- 
ber 3 to 30.20, and on the Rhode Island Greening variety, from 
30.20 per cent alive on same date to one-tenth of 1 per cent alive by 
February 27—practical extermination. 
Carbon-bisulphid series (Table X).—Treatment of scale-infested 
fruits with carbon bisulphid at strengths varying from 0.069 to 1.81 
cubic centimeters per cubic foot and for a period of three hours failed 
to kill the scales to any extent. No injury resulted to the varieties 
of fruit used, namely, Baldwin and Rhode Island Greening. 
