The relationship of insects to the deterioration of stored grain by fungi

The data presented tests the hypothesis that knowledge of basic biological relationships between insects and fungi in the stored grain ecosystem can open new paths for management of the system. Evidence indicates: (1) some storage insect species are disseminators of storage fungi and some are exterminators; (2) some storage fungi attract storage insects and promote their population increases and other repel and secrete toxins harmful to insects; (3) certain morphophysiologic, biochemical similarities of fungi and the early developmental stages of insects suggest that new protective chemicals, 'insecticidal fungicides', could be designed or specifically sought. A specific example of a naturally occurring compound with dual action, sorbic acid (2,4-hexadienoic acid), is given and its effect on both insects and fungi is discussed. Sorbic acid is the only compound in the U.S. presently labelled by the FDA (Food and Drug Administration) as GRAS (Generally Regarded as Safe) and registered by the EPA (Environmental Protection Agency) for use on grain (maize) in storage.