WAYS TO SOLVE STORED-PRODUCT INSECT PROBLEMS 
The discussion thus far has presented some of the insect problems associated with 
stored products and described our progress in solving them. It is appropriate that we 
should now give some attention to further research needed. It is only natural that the 
current emphasis on pesticide residues should influence the trend of planning for future 
research. We must find ways to reduce or eliminate residue hazards. 
The popular and timely thing to do now is talk about the use of insect parasites as a 
substitute for pesticides. This approach may be practical and effective for controlling 
insects in the field, but it is not for those attacking stored products. A number of para- 
sites of stored-product insects are known, They are often abundant where a commodity 
is heavily infested. The difficulty isthatthereis always a lag between population increase 
of the pest species and the time the parasite brings the pest under control. By that time 
there are too many of the pest insects present to be tolerated in a stored product. Con- 
tamination has already occurred and much feeding damage has resulted. Furthermore, 
the presence of the parasites in most instances is just as objectionable as the host 
species. There are very few people who would relish a bowl of breakfast cerealora slice 
of bread with insects in it, even though they were informed this was a beneficial parasite 
used to prevent contamination of their food with stored-product insects. Those who wish 
to give impetus to the use of parasites against stored-product insects should explore with 
the Food and Drug Administration the possibility of establishing tolerances for parasites 
in food. 
There have been exploratory trials in which fungi that attack stored-product insects 
have been used. These have not been successful, probably because moisture levels under 
storage conditions are so low thatfungidonot thrive. There may be possibilities for using 
other insect pathogens such as bacteria, viruses, or protozoa. We are initiating some 
work to explore the possible use of Bacillus thuringiensis against pests in storage ware- 
houses. A possible limiting factor in the use of pathogens is the specificity of many 
of the organisms. In stored-product entomology a problem is seldom limited to one or 
even a few species. Measures used must generally be effective against a large number of 
diverse species. There are exceptions where the useof pathogens could be appropriate. 
Attention should be given to physical or nonchemical means that could be used against 
stored-product insects. A number of forms of radiant energy are effective. These include 
high-frequency sound or electrical waves, gamma rays, cathode rays, and others. The 
difficulty has been to develop the radiations in sufficient quantity or intensity, to produce 
them economically, or to handle them efficiently and safely enough to treat large 
guantities of products as rapidly as must be done under commercial conditions. Tech- 
nological developments are gradually making improvements that may eventually enable 
practical applications to be worked out. 
Greater attention should be devoted to such factors as sanitation and thorough clean- 
ing, handling methods for raw and finished products, and other operational procedures in 
relation to insect problems. Even the manipulation of environmental factors may be 
utilized as a corrective measure. The ventilation of an area or the aeration of a com- 
modity may be helpful. Controlling the temperature, relative humidity, or the moisture 
content of a product may eliminate some insect problems. All of this is especially 
pertinent in the processing industries, where the maintenance and the nature of construc- 
tion of buildings, machinery, and equipment are also highly important. 
It will be noted that the preceding emphasizes prevention rather than control. A very 
few firms have already learned that they can reduce to a minimum the needs for pesticide 
applications by proper attention to these matters. There is an urgent need to apply 
technical entomological knowledge to the subject. We feel this is just as truly a research 
as some other areas of investigation, and that it could be highly productive of valuable 
results. It has received little attention andnot much practical advantage has been taken of 
what is already known. One of the needs is to obtain figures that will prove to management 
that money spent along the right lines will bring about savings in the long run. 
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