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Feeding experiments with the polyphagous southern armyworm, Prodenia eridania (Cramer), show that the larvae reject ferns. Solvent extracts and extracted leaf powders of ferns were incorporated in agar-casein diets to test their deterrency to feeding larvae. Ferns appear to be protected by a water-soluble factor. The evolution of this protection has been suggested.
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Hoo et al. (1964) studied this question.
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