Submitted to: American Society for Mass Spectrometry
Publication Type: Proceedings
Publication Acceptance Date: 3/15/2009
Publication Date: 6/1/2009
Citation: Walse, S.S. 2006. HPLC-MS analysis of pheromone glucoconjugates in oral secretions of male Anastrepha Fruit Flies. American Society for Mass Spectrometry Conference, May 31-June 4, 2009. p. 561. Interpretive Summary: Eight species of Anastrepha fruit flies are considered to be economically significant pests. Volatile pheromones produced by males of this genus are key factors in their natural mating strategy. Males aggregate in display areas, or leks, to attract females. Males typically mark mating sites, such as leaf surfaces, by depositing aqueous oral secretions that contain sugar, as well as aggregation pheromones. Several of the pheromones are volatile terpenoids and their communicative function has been characterized; yet, the function of the relatively non-volatile pheromone glycoconjugates remains unknown. The goal of this study is to survey Anastrepha males for pheromone glycoconjugates with the goal of gauging inter-species diversity and elucidating their potential purpose(s). This knowledge will fuel applied IPM programs for Anastrepha control if the communicative function of the pheromone glycoconjugates is exploitable in an practical and economical sense.
Technical Abstract: Using high performance liquid chromatography combined with ESi, APCI, and PBEI mass spectroscopy, novel terpenoid glycoconjugates were identified in oral secretions of several Anastrepha fly species; these findings suggest that non-volatile pheromone signals are used in their lek mating strategies. The terpenoid aglycons, which originate in salivary glands and traverse through interconnected ducts to the crop, are likely conjugated enzymatically as glucosidases and glucotransferases often function in an anabolic capacity. The communicative function(s) of the glucoconjugates is likely tied to the integrity of the O-glucosyl ester linkage. Enzymic, or abiotic, hydrolysis of the glucoconjugates in the oral secretions would prolong the emission of from lek sites. This is curious from an evolutionary perspective, because many fruits control the release of their volatile attractants from sugar-based matrices in this manner. Alternatively, pheromone activity of the glucoconjugates, or the enzymatically liberated aglycon, may be related to the tasting of oral secretion scent markings by conspecifics, which is a common behavior within Tephrtidea.