Many volatile alcohol and ester metabolites of the lesser grain borer (LGB, Rhyzopertha dominica) cultured on wheat grain were identified. Volatiles from infested samples at 80 degrees C were collected on Tenax absorbent, thermally desorbed, and analyzed by gas chromatography (GC) using infrared (IR) and mass (MS) detectors for component identification. A solid-phase microextraction (SPME) technique was used to analyze selected samples with a GC-MS system set up for obtaining chemical ionization mass spectra. SPME was also used in a synthesis process required to identify ester metabolites. Predominant compounds in LGB-infested grains were 2-pentanol and its esters of 2-methyl-2-pentenoic (A) and 2,4-dimethyl-2-pentenoic (B) acids, which are known aggregation pheromones, dominicalures 1 and 2. 2-Pentanol esters of saturated A, beta-keto- and beta-hydroxy derivatives of A and B, homologues of A and B, and acid moieties lacking the 2-methyl substitution were found. Other straight- and branched-chain secondary alcohols and their esters were also observed. Reexamination of GC-MS-IR data acquired in previous investigations of LGB cultured on sorghum grain and commercial samples in a grain odor study showed the presence of many LGB metabolites in addition to the known dominicalures.