تاثیر برخی از کنه‌کش‌های جدید بر ﮐﻨﻪ‌‌ی شکارگر Allothrombium pulvinum Ewing (Acari: Trombidiidae) در باغ‌های مرکبات

The predatory mite, Allothrombium pulvinum Ewing is one of the most important species of the Trombidiidae family in different parts of the world and is one of the natural enemies of many pests. This mite is important in Mazandaran province citrus orchards and it feeds on aphids, Pulvinaria aurantii eggs and harmful mites. The use of non-selective chemical acaricides in orchards has reduced the population of this mite. So, in this study efficiency of acaricides including spirodiclofen (Envidor), Benzoximat (Citrazon), Fenpiroksimat (Ortus), Pyridaben (Sanmite), Fenazaquin (Pride), Volck oil and Palizin on the predator mite population were investigated. For this purpose, an experiment was conducted in a randomized complete blocks design with seven treatments, including spirodiclofen (0.5), benzoximat (1), fenpiroksimat (1), Pyridaben (0.5), fenazaquin (0.5), volck oil (15), palizin (2.5) liter in 1000 liters water and control treatment (water) in 4 replications. This experiment was done during winter spraying of citrus trees in March 2018. The number of live adult mites under the leaf, in the gaps and between the branches was recorded in the tables at the time of 1 day before and 1, 3, 7, 14 and 21 days after treatment. The percentage of the effect of acaricides was calculated by using the Henderson-Tilton formula and the data were analyzed by SPSS software version 24. Data analysis results were divided into groups according to the International Organization for Biological Control (IOBC). According to the results, Pyridaben with 83.46 and 72.91% mortality rates, respectively, were produced the highest mortality at 1 and 3 days after spraying, respectively, and according to the IOBC classification were classified in the hazardous and medium-risk group. While volck oil and palizin had the lowest mortality rates, 26.19 and 20.31% at 1 and 3 days after treatment and were placed in a group with less harmful. After 7 days of treatment, spirodiclofen with 80.27% mortality, produced highest mortality rate and it was placed in a dangerous group. At 14 and 21 days after spraying, fenpiroksimat with 81.71 and 92.38% mortality, was placed in the dangerous group. In addition, volck oil and palizin treatments caused 18.71 and 15.62% mortality after 21 days, 12.62 and 8.08% after 14 days treatment, respectively. The total results of this study showed the use of Pyridaben, spirodiclofen, benzoximat and fenpiroksimat, respectively, had a highly harmful effect, while volck oil and palizin had little effect on the mortality of predator mite.