AN INVESTIGATION ON OPTIMAL HEIGHT AND DIRECTION OF YELLOW STICKY TRAPS BAITED WITH SEX PHEROMONE FOR CAPTURING THE OLIVE FRUIT FLY, BACTROCERA OLEAE (DIP.: TEPHRITIDAE)

The olive fruit fly, Bactrocera oleae (Rosii), is one of the injurious pests of olive that has caused considerable damage to olive orchards in recent years. An investigation was carried out at Tarom Olive Research Station, Zanjan, Iran, during 2008 to 2010 to determine the optimal height and direction of yellow sticky traps + sex pheromone for capturing B. oleae. A split plot design with four replicates was used in experiments, where the four main directions and three heights of one, two, and three meters were considered as the main and sub-main plots, respectively. Due to the past occurrence of the pest in Tarom, the traps were placed on olive trees in late September and weekly sampling was conducted throughout the autumn. Results revealed that the height of trap, unlike direction, significantly affected the capture of the olive fruit fly in all three years. The effect of trap direction was only significant in 2009, when the region experienced the highest density of the pest. Mean comparison of the effect of height in each year showed that the highest and lowest number of catches was in heights of three and one meter, respectively. In 2008, 2009 and 2010, total catches (both males and females) per trap in heights of one and three meters were 5.25 and 9.63, 21.46 and 53.46, and 1.33 and 3.27, respectively. In 2009, the traps in the west and south directions captured the high numbers of 46.39 and 42.04 olive fruit flies, respectively; while the minimum number of catches, 29.20, occurred in the north direction. In Tarom, based on the results, it is recommended that yellow sticky traps baited with sex pheromone be placed at a height of three meters being in the direction of west and south.