The population trend of Palpita unionalis in different olive varieties in Egypt
Jasmine moth (JM), Palpita unionalis (Hübner) (Lepidoptera: Pyralidae) is a very important pest in the commercial, densely planted olive orchards in Egypt. In years of its highest population density, it can destroy a significant part of the crop. The objectives of this study were to determine the male flight trend and egg laying trend of the JM in three large plots of different olive varieties (two varieties/plot) in two successive fruiting seasons. Differences in male flight trend and egg laying trend of JM were observed among the different varieties (‘Sennara’, ‘Toffahi’, ‘Shamy’). In 2003, more males were captured in traps placed in the Sennara/Toffahi plot than in the two Shamy/Toffahi plots. Egg densities were higher on Toffahi trees grown between Sennara trees than on Toffahi trees grown between Shamy ones. In 2004, in the plot where Toffahi and Sennara were grown together, JM females laid more eggs than in the olive plot where Toffahi rows alternated with Shamy rows. The results suggest that the Shamy variety discouraged gravid females from ovipositing, compared with Toffahi or Sennara varieties. In conclusion, olive variety, cropping system (mixed culture) and trapping season are among those characteristics that affect this pest.