Do chemical signals mediate reproductive behavior of T rupanea vicina , an emerging pest of ornamental marigold production in C alifornia?

Abstract A variety of signals mediate reproductive behaviors of T ephritidae, and studies of such behaviors have focused predominantly on economically important tephritid pest species. T rupanea vicina ( W ulp) ( D iptera: T ephritidae: T ephritinae), an A steraceae‐feeding fruit fly, was not considered a pest until recently, when large populations developed on marigolds in C alifornia ( USA ) nurseries. Understanding courtship behavior and the signals that mediate mating behavior in T . vicina could produce leads for new methods of controlling this emerging pest species. Most of the sexual behaviors observed in T . vicina were expressed by males and reflected the general characteristics of known reproductive behaviors in the genus T rupanea . Analyses of headspace volatiles indicated the presence of almost exclusively one male‐specific compound, 1‐nonanol. Age‐related changes were observed in the amount but not in the composition of the male‐produced volatiles. Aerations of males showed no diel periodicity in 1‐nonanol production, but an increase after mating. Solid‐phase microextraction wipe samples from various body parts of male T . vicina showed that 1‐nonanol was concentrated on the abdomens of males exhibiting pleural distension. Laboratory bioassays failed to detect any strong attraction of either sex to synthetic 1‐nonanol. Although the functional role of 1‐nonanol in T . vicina 's biology is not yet clear, we suggest that it must have some role in the life history of this species, given the relatively large amounts in which it is produced, and the specialized structures used in its production and release. Analysis of cuticular hydrocarbons extracted from males and females showed pronounced sexual dimorphism in the cuticular lipid profiles, suggesting that these compounds may have a role as short‐range and contact pheromones.