Insect pest control, phytoalexins

Plant phytoalexins [natural plant antibiotics] [1] have the potential of becoming a new class of useful compounds in the control of insect pests. Some phytoalexins have been demonstrated as deterrents to insect feeding. Considerable progress has been made to characterize them chemically and to extend the study of their function in plant disease resistance, but exploration of their role in the control of insect pests is just beginning. 

A better understanding of the role of phytoalexins in plant defenses and of the mechanisms of induced resistance may potentially open a powerful new approach to the control of insect pests of cultivated plants. If indeed, in light of the hypothesis of optimal defense strategies (3), a post-attack response is a more efficient line of defense than the attack-independent accumulation of allelochemics, the exploitation of phytoalexin-producing mechanisms may represent a fertile field for future investigations. Several uses of induced resistance may be conceived. Four of these approaches are briefly discussed. 

Phytoalexins and Their Potential Role in Control of Insect Pests... 

Based on the previous examples, the elicitation of phytoalexins and other inducible compounds in plants by various elicitors might be a successful tactic for controlling insect pests on important crops. This elicitation would need to occur only when the insect feeds, to prevent unnecessary damage to the plant by accumulation of compounds toxic to plant cells as well. Based on presently known carbohydrate elicitors, it seems plausible that plant surfaces could be treated in such a way that the elicitor is carried into the plant upon insect feeding [21]. These carbohydrate elicitors should be stable and should pose no environmental threat since they are most likely non-toxic themselves. 

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