Seasonal population fluctuations of Mediterranean pine bark beetle, Orthotomicus erosus (Wollaston) (Coleoptera:Curculionidae:Scolytinae), in the Tehran Chitgar forest park

One of the main problems of pine trees in the Chitgar park located in Tehran, Iran, is pine bark beetles, which not only cause direct harms to these trees but also is vector of some viral  and bacterial pathogens. To study the seasonal population fluctuations of the pest, the sampling process of adults from pine barks was performed in different regions of the park in 2015 to 2017. Twelve infected centers in the park were selected and four cross trap were installed in each center. The mass capturing pheromone of Orthotomicus erosus and pine kairomone dispensers were used in each trap. The distance between traps was about 50 meters. According to the observed data, the emergence of adult beetles was started in early April and continued until mid-December. The average daily capture per trap was four beetles. From mid-December onwards, no beetles were caught in the traps. Mediteranean pine bark beetle had at least six flight peaks in the area of study. The most trapping were observed in 8 June, 28 June, 27 July, 16 August, 5 September and 25 September respectively. The The highest number of trap catches was registered in September, July, August, June, September and October, with 9.2, 7.7, 7.2, 5.7, 2.4 and 1.6 beetles per trap respectively. Also, the mean average of total capture during spring, summer, autumn and winter were 401, 1159,114 and zero beetles per trap; so, the most activity of the pest was observed in summer, spring and autumn respectively The highest number of beetle was in the north and the least was captured in the south of the park.