There are international complications in dealing with some phases of ship infestations 
that bring about difficult situations to handle. Wehave discussed this with an official from 
the Rome office of the Foodand Agriculture Organization. It is possible that a cooperative 
international approach can be arranged by setting up a liaison through that office. 
PACKAGING 
A food processor loses the benefit of all the effort and expense devoted to producing 
and packaging an insect-free product if the package is invaded after it leaves the plant 
and the product is infested when it reaches the consumer. Adequate protective packaging 
is costly, sometimes out of economic balance withthe value of the product inside the pack- 
age. 
We have conducted extensive research for the last several years, with the objective 
of developing more effective, economical, insect-resistant packaging for foods and other 
susceptible products. A great dealhas beenlearnedabout the problem and some significant 
advances have beenmade. The researchis dividedinto three phases--package construction 
and closures, the materials usedas package components, and treatment that may be applied 
to impart insect resistance. 
Industry has been extremely interested in this research and we have derived tre- 
mendous benefits from their cooperation and participation in the program. In a single 
large-scale test we have had as many as eight or nine cooperators from the insecticide, 
paper, container, and food industries. Each cooperator contributes some material or 
service, and by pooling these resources we can accomplish much more than by individual 
effort. 
We have learned that good package construction and closures are highly important in 
preventing insect invasion. In one test to evaluate several different types of closures, the 
preliminary results were so striking that a cooperator spent $100,000 for a new machine 
to provide a different kind of wrap for his product, even before the experiment was com- 
pleted. 
A number of kinds of plastic films and other materials used in package construction 
have been evaluated for their ability to resist insect penetration. The information obtained 
is highly beneficial in selecting the best components for packages. 
Simple laboratory tests have been devised to evaluate the effectiveness of chemicals 
as potential treatments to increase the insect resistance of packages. Promising ma- 
terials are further tested under simulated warehouse storage conditions in the presence 
of heavy infestations of about 15 species of stored-product insects. Some experimental 
treatments have given protection against invasion and penetration for 12 to 15 months. 
In using chemical treatments the potential migration of the chemical through the 
package and into the product must be investigated. A simple test method has been devised 
to use in the search for effective barrier films and other means for precluding such 
migration. The method now includes chemical analysis to detect the migration of the 
material used for treatment. It is anticipated that radioactive tracer techniques would 
facilitate this work and greatly speed up the detection of chemicals in following their 
migration. We are in the process of installing a tracer laboratory and this is one of the 
uses to which it will be put. 
We are interested in the possibility of using repellents rather than toxicants for 
package treatments. An efficient repellent could be a compound with low mammalian 
toxicity, thus reducing the residue hazard. Furthermore, it would be more desirable to 
keep the insects away from food packages than to kill them after they crawl over the 
containers. This would avoid the presence even of dead insects. We have evaluated over 
800 compounds as potential repellents and several promising ones are in the second phase 
of testing. 
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