تأثیر محلول‌پاشی با سموم بیولوژیک روی کرم جوانه خوار بلوط Tortrix viridana L. در استان چهارمحال و بختیاری

Green oak moth Tortrix viridana L. is an important oak pests whose larvae cause a lot of damage to the forests of central Zagros every year by feeding on the buds and leaves. Considering the adverse effects of chemical insecticides due to the destruction of natural enemies, environmental destructive effects, pesticide residues in natural resources and the destruction of beneficial insects, especially honey bee, and also the presence of many villages in the region; biological and microbial pesticides for spraying against pests should be replaced with common chemical pesticides. Therefore in this study in the spring of 2020, five stations with a distance of two kilometers from each other and each station with an area of one hectare were selected in the Mashayekh area of Kiar county. The experiment was performed in a randomized complete block design with 4 treatments and 4 replications. Treatments included biological pesticides, powdery BT (Biogard) at a rate of 1 kg/ ha, liquid BT (Biolep) at a rate of 2 L/ ha, microbial insecticide Beauveria bassiana (Naturalis) at a rate of 2 L/ ha and spraying with water as a control. Spraying was carried out on 3 and 4 April with a relative temperature of 13 to 17 ° C, relative humidity of 40 to 50%, by tractor sprayer. Three, five, seven and ten days after spraying, visits and random sampling were performed. Data were analyzed with SAS software and the tables of analysis of variance and regression analysis on the frequency of the pest were examined.. Results showed that powdery BT had the highest effect with 49.7%, and after that, liquid BT with 36.3% and Beauveria bassiana with 25% effectiveness on the target pest, respectively. Therefore, microbial pesticides showed the highest efficacy against the larvae and therefore could be recommended for the biological control of the green oak moth.