Volatiles attractive to the Mexican fruit fly (Diptera : Tephritidae) fromeleven bacteria taxa

Filtrates of 11 bacteria representing 4 higher taxonomic categories were at tractive to Mexican fruit flies, Anastrepha ludens (Loew) (Diptera: Tephrit idae) in laboratory bioassays. All bacterial filtrates were more attractive at pH 9 than at pH 5 although filtrates at pH 5 were more attractive than water controls. The effects of pH on attractiveness of filtrates were consi stent with an hypothesis that attractive principals of bacterial filtrates were various nitrogen-containing compounds and carboxylic acids that became more volatile at specific pH's resulting in increased attractiveness. Vola tiles produced by the bacteria were sampled by solid-phase microextraction and identified by GC and CC-MS. Attractive principals identified were ammon ia, aliphatic amines, pyrazines, imines, and acetic acid. Relative amounts of most of the chemicals were not closely tied to bacteria taxonomy.