Biology and economic damage of peach twig borer Anarsialineatella(Lepidoptera: Gelechiidae)in almond orchards ofSaman

Biology and economic importance of peach twig borer were investigated during 2000-2001 and 2016-2017 in almond orchards located in Saman, Chahar mahal VaBakhtiary, Iran.From the beginning of the growing season, almond orchards were visited weekly to collect infected branches and fruits transferred to laboratory to isolate and rear different developmental stages of the pest. Moreover, pest population changes were investigated by installing pheromone traps in almond orchards. Results showed that the pest spends winter in the form of first and second instar larvae within the terminal buds of the branches of host trees. Pest larvae feed on shoots and buds in the early growing season. Since mid-June, the larvae fed upon immature apricot, peach, and almond fruits, causing them to fall. The average infection rate in immature fruits of “Mamaee” almond cultivar was 2.95% and 1.47% in 2000 and 2001, respectively. The amount of “Sefid” almond cultivar infection was determined18% in heavy infested orchards. The number of infested fruitand branches in peach trees were higher than almond trees.The amount of infestation in almond and peach trees in the west and south directions was statistically more than the north and east directions. In laboratory conditions, with 25± 2 ° C, 50±10% RH and 8:16 hours (L: D) the embryonic period of the pest along with larval and pupal stages were lasted 5-6, 12-16 and 7-12days respectively. The pest completes three generations per year. The peak of the first, second and third generation occurs in late May, the second week of July and the last week of September respectively.