Identification, distribution and estimation of economic damage of dominant pest rodent Species in Pistachio orchards of Kerman province.

Rodents are a group of animals belonging to the order Rodentia and due to the unusual growth of the incisors teeth besides eating,to control their growth,they have to chew various products including agricultural,industrial ,domestic,….,and in this way cause huge domage.During the past few years because of prolonged drought there have been damage to their natural habitat and there fore their population have increased enormously in the agricultural fields and orchards .The damage caused by rodents is quite noticeable in the alfalfa yields ,orchards and palm groves .An interesting observation is the enormous in crease in their population in pistachio orchards in the region of Siriz in the Zarand town.the damage is so high that young and middle aged trees with thick trunks have been cut seen to be by the rodents,and this type of damage has been reported for the first time in Iran.In order to findout the species distribution and economic injury level of rodents in pistachio orchards this project was designed and conducted.few infested areas in the province was visited and three regions named Siriz ,Chatrood and baghein were selected for conducting the experiment three orchards were selected in each region with rodents colonies.in order to investigate the dominant species of the rodents in these regions snaptraps were used in a month when their activity was at pick .collected samples were transfered to the laboratory for taxonomy ,results were analysed using Mstat statistical package and Nesokia.indica was identified as the dominant species.According to the investigations rodent Management cost is at least half of the cost of damages caused .in other words to reach equilibrium in control ,costs could be increased by 53%. Also other factors stadied show that management of this pest in the three regions investigated is not equal,and this difference shows that it is essential to consider technical ,social and economical characteristics of a region when programming pest management and making decisions.local management methods by the farmers shows the highest percentage belongs to chemical and farming methods used together.