Article révisé par les pairs
Résumé : The Colorado beetle is protected against predators by the secretions of defensive glands located on the pronotum and the elytra. The single major compound of the secretion was identified as γ-L-glutamyl-L-2-amino-3(Z),5-hexadienoic acid by spectroscopic and chemical methods. This compound, which contains a nonprotein β,γ-unsaturated amino acid, is toxic to ants (Myrmica rubra) at a concentration 10-2 molar, which is less than its estimated concentration in the secretion (1.8 x 10-1 molar).