کنترل شیمیایی کرم خراط در تنه و سرشاخه اصلی درخت گردو به روش اّسکو

The leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae), a wood borer of fruit and fruitless trees, has caused severe damage to walnuts, host trees in different regions in Iran. To control larvae of the leopard moth in the trunk and main branches of infested trees, brake wire and toxic insecticide paste such as Anti-Tarlo® are applied. In this research, two mechanical and chemical methods were used to control the larvae of leopard moth. Several 15-infested walnut trees (20 years old) were selected for each treatment. This research was conducted in April 1402 in the Chahar Bagh area of Karaj. The infested trees had larval holes in their trunks and main branches with sap leaks and excrement coming out of the holes. The duration of treatment and the mortality of the larvae in infested trees were recorded in both methods. The brake wire, as a mechanical control method, was inserted into the larval holes of the trunk and main branches. In addition, in the chemical control method, which is called the Osku method (taken from the native knowledge of gardeners of Osku city, near Tabriz, Azarbyjan shargi Province), the aerosol formulation of the insecticide was used. The modified nozzle of insecticide aerosol was directly inserted into the larval holes and transferred the insecticide vapor into the larval corridor. The results showed that In the Osku method, the larvae inside the corridor were quickly knocked down and fell to the opening of the larval hole, and dead larvae can be observed one day after treatment. The duration of treating a larval hole by the Osku method took less than 30 seconds, and the total time for treating an infected tree with 5 larval holes took less than 3 minutes, and its efficiency was 92.5%. In the brake wire method, it took at least 3 minutes to remove the larvae inside each hole, and it took at least 15 minutes to treat a walnut tree with 5 infected holes. The mean efficiency percentage in the wire method was 80.8%. The comparison of the efficiency percentage between two treatments, based on the T-test (Tvalue=2.16, Pr=0.04), was significant at a 5% level. To have 100% mortality of larvae by the Osku method, it is recommended to use putty or aquarium glue to block the opening of the hole so that the poison vapor remains inside the corridor. In the brake wire method, the user or farmer needs to have more experience working with brake wire. Considering the positive features of the Osku method, such as convenience, high operation speed, and higher efficiency, it can be used to control the earthworm in infected tree trunks.