Allylglucosinolate and herbivorous caterpillars: a contrast in toxicity and tolerance.

Allylglucosinolate, found in many cruciferous plants, is acutely toxic to Papilio polyxenes larvae, which do not normally attack crucifers. By contrast, larval growth of Pieris rapae, a crucifer specialist, is not affected even by artificially high concentrations of allylglucosinolate. Larval growth of Spodoptera eridania, a generalist feeder, is inhibited by high but not by low concentrations of the compound.