Similar worldwide patterns in the sex pheromone signal and response in the oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae)

Abstract

The response of Grapholita molesta (Busck) males to three-component sex pheromone blends containing a 100% ratio of the major sex pheromone component, (Z)-8-dodecenyl acetate and a 10% ratio of (Z)-8-dodecenol, but with varying ratios of (E)-8-dodecenyl acetate (0.4, 5.4, 10.4, 30.4, and 100.1% E-blends) was tested with populations in eight stone and pome fruit orchards in Europe, Asia, and North and South America. Traps baited with the 5.4% E-blend caught significantly more males than traps with any other blend with all populations. Significantly more males were caught in traps baited with the 10.4% E-blend than in traps with the remaining blends, except with the 0.4% E-blend in Turkey. Significant differences in male moth catches occurred between the other blends with the 0.4>30.4% E-blend, and the 30.4>100.1% E-blend. Male moth catches with the 100.1% E-blend only differed from the hexane control in Chile. No apparent differences were noted to these blends in populations collected from pome or stone fruits. Flight tunnel assays to synthetic blends with a subset of populations were similar to the field results, but the breadth of the most attractive E-blends was wider. Flight tunnel assays also demonstrated a high level of male-female cross-attraction among field-collected populations. Female gland extracts from field-collected populations did not show any significant variation in their three-component blends. The only exceptions in these assays were that long-term laboratory populations were less responsive and attractive, and produced different blend ratios of the two minor components than recently collected field populations.

We would like to thank the financial support of MEC, Spain (AGL2010-17486) to C.G., D.B, and L.A.E., and the Chilean grant ‘Conicyt MEC 80120005’to C.G. In Girona, Spain, Cesca Alcalá with RTA conducted the field experiments and Maria Carbó obtained the research sites. In Turkey, the research assistant Bilgi Pehlevan (Uludag University, Turkey) was very helpful in these studies. In Korea the work was supported by the Basic Science Research Program through the National Research Foundation of Korea. In Italy, Matteo Anaclerio and Manuela Cigolini (Catholic University) were very helpful. Help with the studies conducted in Oregon was provided by Rick Hilton at Oregon State University, Medford, OR. Laboratory colonies from Pennsylvania were provided by Greg Krawczyk, Penn State University, Biglerville, PA, and from California by personnel at the USDA, ARS Laboratory, Parlier, CA. Jean-Claude Tournié, of Prestagro, collected insects in France and shipped them to Spain.