Sex Attractant Pheromone from the Rice Stalk Stink Bug, Tibraca limbativentris Stal Miguel Borges & Michael Birkett & Jeffrey R. Aldrich & James E. Oliver & Mitsuo Chiba & Yasuhiro Murata & Raul A. Laumann & José Alexandre Barrigossi & John A. Pickett & Maria C. B. Moraes Received: 8 May 2006 / Revised: 26 July 2006 / Accepted: 17 August 2006 / Published online: 7 November 2006 # Springer Science + Business Media, Inc. 2006 Abstract The male-produced sex pheromone from the Brazilian rice stalk stink bug Tibraca limbativentris is reported. Olfactometer bioassays with sexually mature males and females showed that males attracted females, which suggests that males release a sex pheromone. Males were not attracted to either sex, nor were females attractive to conspecific females. Attraction of the females to males was highest at night. The headspace volatiles collected from male and female bugs were analyzed by gas chromatography (GC) and GC–mass spectrometry. Two male-specific compounds were identified as isomers of 1′S-zingiberenol, whereas a series of defensive compounds were identified in extracts from both sexes. Zingiberenol has three chiral centers, and the nonselective syntheses used produced two groups of isomers, zingiberenol I containing four isomers, namely (1RS,4RS,1′R)-4-(1′,5′-dimethylhex-4′-enyl)-1-methylcyclohex-2-en-1-ol, and zingiberenol II containing the other four isomers, namely (1RS,4RS,1′S)-4-(1′,5′-dimethylhex-4′-enyl)- 1-methylcyclohex-2-en-1-ol. Both groups of stereoisomers were more attractive than hexane J Chem Ecol (2006) 32:2749–2761 DOI 10.1007/s10886-006-9197-6 M. Borges (*) : R. A. Laumann : M. C. B. Moraes Embrapa Genetic Resources and Biotechnology, Cx. Postal: 02372, Cep.: 70849-970, Brasília, DF, Brazil e-mail: mborges@cenargen.embrapa.br J. R. Aldrich : J. E. Oliver USDA-ARS Chemicals Affecting Insect Behavior Laboratory, BARC-West, B-007, Room 301, 10300 Baltimore Avenue, Beltsville, MD 20705, USA M. Birkett : J. A. Pickett Biological Chemistry Division, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK M. Chiba : Y. Murata Fuji Flavor Co. Ltd., 3-5-8 Midorigaoka, Hamura City, Tokyo 205-8503, Japan J. A. Barrigossi Embrapa Rice and Beans, Cx. Postal: 179, Cep.: 75375-000, Goiânia, GO, Brazil