Seasonal dynamics of population and infestation of peach twig borer, Anarsia lineatella Zeller (Lep.: Gelechiidae) on different varieties of peach in Mazandaran

Peach twig borer, Anarsia lineatella Zeller, as one of the most important pests of stone fruit trees in Iran and worldwide, causes severe damage annually. In this research, the pest seasonal dynamics on early (Prunus persicae var. keres), moderate (Prunus persicae var. zafarani) and late (Prunus persicae var. sibi) ripening peach cultivars was studied by using pheromone traps in three orchards (1 ha), in Mazandaran province during 2012-2013. Four pheromone traps were placed at 1.5-2 m height per orchard for weekly monitoring the adult moths. To determine the larval infestation, 10 trees (per orchard) were selected and 40 new shoots and 100 fruits (from each tree) were randomly inspected per week. The results indicated that A. lineatella had 3-4 generations and overwintered as 1st and 2nd instar larvae inside terminal parts of infested shoots. The first moths were trapped in mid-April with maximum population appeared three weeks later, coinciding with main flushing stage of the trees. The three main peaks of the moths were observed in April, June and July, which almost concur with the huge flushing stage of the trees. The 1st generation larvae generally attacked the new shoots. Feeding activity of second generation of pest was very important for moderate and late ripening cultivars. Fruit damage on moderate and late ripening cultivars was determined around 4.2 and 5.5 percent, respectively. In conclusion, under high density of 2nd and 3rd generations, severe damage on the fruits may be expected and consequently control recommended.