Comparative pheromone analyses of three bactrocera fruit fly species of economic importance

Fruit flies are significant horticultural pests in many countries, including Australia. Organophosphate insecticides have been typically used to control fruit fly infestation, however these compounds have been banned in recent years, hence the development of alternative control methods is of paramount importance. In this study, the chemical profiles for males and females of three pest species in Australia, Bactrocera frauenfeldi, B. kraussi and B. musae, were investigated. Compounds were identified from rectal gland extracts and headspace collections, and confirmed by comparison of GC retention times and MS fragmentation patterns to authentic samples. In total, 27 compounds were preliminarily identified in the chemical profiles, and 17 were confirmed by comparison to authentic samples. Across all species, and both sexes, three main chemical classes were present: esters, spiroacetals, and acetamides. Also, a larger number of compounds were identified in rectal gland extracts than headspace collections. Females typically produced a wider range of compounds, including acetamides, spiroacetals and esters, with the latter being the major components. Males typically produced one major component, usually a spiroacetal, and had additional minor components. The only exception was males of B. musae, who were found to produce a range of compounds in their chemical profile, predominantly esters.