Antifeedants are produced by plants to repel herbivores through distaste or toxicity. These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity. Antifeedants exhibit a wide range of activities and chemical structures as . Examples include rosin, which inhibits attack on trees, and many , which are highly toxic to specific insect species,
History
"Plant-derived insecticides (e.g.,
rotenone,
,
, and
nicotine) have been used for insect control since antiquity."
The active ingredients in these plants have been purified and modified. For example, variations on pyrethrin have spawned a large number of synthetic insecticides called
.
Culinary implications
In addition to their role defending the plant, antifeedants often confer taste or odors, enhancing the flavor of certain plants. Examples are provided by cruciferous vegetables including
mustard plant,
cabbage, and
horseradish, which release pungent oils containing
glucosinolates when the plant material is chewed, cut, or otherwise damaged.
The odorous components of
garlic are thought to have evolved to deter insects.
