Effect of lucerne saponins and Lotus condensed tannins on survival of grass grub, Costelytra zealandica

Abstract

Crude extracts of lucerne (Medicago sativa) and Lotus pedunculatus root were toxic when administered orally to third-instar Costelytra zealandica larvae. Purified saponins from lucerne root were alone found sufficiently toxic to account fully for the activity of the crude extract. Condensed tannins extracted from L. pedunculatus and L. corniculatus had no effect on larval survival when administered at levels equivalent to those present in crude extracts.

Keywords:

• Medicago spp.
• Lotus spp.
• Trifolium spp.
• root extracts
• saponins
• condensed tannins
• oral toxicity
• Costelytra zealandica
• grass grub