Article révisé par les pairs
Résumé : The sting of the Neoguinean pseudomyrm ecine ant, Tetraponera sp. (group punctulata) is modified in astructureresembling a drawing pen. These ants do not sting, but smear upon enemies a contact poison. The venomwhich originates from the poison gland is a mixture of eight alkaloids with an original tricyclic ring system. The structure of the majorcomponent, tetraponerine-8, has been determined by X -ray diffraction analysis. Thepoison of Tetraponera is highly efficient in deterring aggressive sympatric ants and tetraponerine -8 shows toxic properties against Myrmica rubra when applied topically, with a LD50 of 5 x 10-4mg/mg of ants. © 1987, Walter de Gruyter. All rights reserved.