ANT (HYMENOPTERA:FORMICIDAE) VENOMS FROM CAATINGA BIOME: AN UNEXPLORED BIODIVERSITY

AUTHORS: QUINET Y. (1), DE BISEAU J.C. (2)

(1) Laboratório de Entomologia, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil, (2) Laboratoire d'Eco-Ethologie Evolutive, Université Libre de Bruxelles, Bruxelles, Belgium

Chemical defence is the most important defence mechanism in ants, and includes injection, spraying or topical application of venons. However, among nearly 11.000 known ant species, the defensive compounds of hardly tens of them have been analysed, mostly in a purely chemical way. Chemical composition and/or biological properties of defensive compounds still remain unknown in many ant groups. With more than 2000 ant species, Brazil has one of the most diverse ant fauna. However, important Brazilian biomes, like "caatinga", remain poorly investigated. Our study aimed to investigate the chemical diversity and biological functions of the venoms in the Crematogaster genus, one of the most successfull groups of ants, with more than 400 species. Instead of injecting venons, as most primitive ants do, Crematogaster ants use their modified sting to accumulate venom, and applicate it, topically, on the integument of enemies The analysis of the venom produced by species of the "caatinga" biome showed a high chemical diversity including long unsaturated hydrocarbon chains with primary acetate function, furanocembranoid diterpenes, and triacylglycerols, quite differing from the venoms generally found in other ants. Topical application of those venoms on the body of ant and termite target species showed toxic properties. More direct repelent properties were also shown, while in C. montezumia, venom has sticky properties. In addition, the Crematogaster venoms presented antibacterial properties, at least in one of the studied species (C. sp. prox. abstinens). The chemical and functional diversity of Crematogaster venoms emphasize the importance of ants as a group with high potentialities for the discovery of new natural products, as well as the need to invest research effort on important and still neglected biomes, like caatinga.

KEY WORDS: ants, venoms, caatinga, biodiversity, Crematogaster

FINANCIAL SUPPORT: CNPq.

CORRESPONDENCE TO: QUINET YVES, Laboratório de Entomologia, Universidade Estadual do Ceará, Fortaleza, Brazil. Phone: + 55 85 31019749. Fax: + 55 85 31012810. Email: yvesq@terra.com.br