PREVENTING INSECT DAMAGE IN HOME-DRIED FRUITS 3 



Use of High Temperatures 



. When properly applied, heat is effective in killing insects and mites 

 infesting dried fruits. Hot water may be used for this purpose for 

 primes and "natural," or unsulfured, raisins. These fruits, placed in 

 a cheesecloth bag, may be dipped in boiling water for 6 seconds to kill 

 insects and their eggs and may then be dried thoroughly before being 

 stored. Dry heat should be employed for treating figs and sulfured 

 fruits. For dates, exposure to about 150° F. for 1 to V/ 2 hours has been 

 found effective, the heat being obtained either in a sun-heated cabinet 

 or in a kitchen oven. Some darkening, stickiness, and change in flavor 

 are likely to be produced when dates are thus heated. 



Cold Storage 



Any temperature below 50° F. will keep dried-fruit insects from 

 breeding and will prevent infestation of clean fruit. Temperatures 

 of about freezing keep these insects inactive, but they may live for sev- 

 eral weeks or longer. At around zero, death occurs within a few days. 

 Persons having available refrigerated locker space can preserve small 

 lots of dried fruits in this way. With raisins, some crystallization of 

 sugar is likely to occur. 



Fumigation 



Although fumes of burning sulfur may be produced in sufficient con- 

 centration and over a long enough time to kill insects and their eggs, 

 the usual sulfuring process cannot be depended on to do this. Fumi- 

 gation can be done in any clean box or metal can capable of being 

 tightly closed. For this purpose a clean galvanized-iron ashcan is well 

 suited, the cover being sealed on with paper tape after the dried fruit 

 and fumigant have been put in. 



For the use of those who wish to fumigate small quantities of dried 

 fruits there are several noninflammable liquid fumigants which are in- 

 expensive and convenient to apply. One readily available mixture 

 contains ethylene dichloride and carbon tetrachloride and is sold under 

 several proprietary names. This mixture should be applied at the 

 rate of about 2 teaspoonfuls per cubic foot of space to be fumigated. 

 It should be poured into a shallow pan placed above the fruit, and 



the container should remain closed for at least 12 hours. Fumigation 

 is most effective in hot weather. 



All fumigating gases are poisonous, and care must be taken to 

 avoid breathing them. The fumigation box or can should be well 

 aired before the treated dried fruit is removed. The fumigation 

 should not be carried on in the dwelling, but in an outhouse from 

 which all members of the household and domestic animals can be 

 excluded. 



Storage Containers 



The use of tight containers, such as glass fruit jars provided with 

 insects and mites from attacking dried fruits. Fruits should be well 

 rubber rings, friction-top metal cans of various sizos, and moisture- 

 vapor-tight containers made for use in freezing storage, will keep 



