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Changes in insecticide susceptibilities and detoxifying enzyme activities were measured in a strain of Tetranychus urticae Koch following repeated exposure to the organophosphate insecticide, chlorpyrifos. Twelve consecutive selection at the LC 60 of the parental strain increased resistance from 8.58 to 91.45 fold. The interaction of some synergists [piperonyl butoxide, triphenyl phosphate and S-benzyl-O,O-diisopropyl phosphorothioate (IBP)] with chlorpyrifos was analyzed in the selected strain. Solely IBP showed a low synergistic effect with chlorpyrifos. The selected strain also demonstrated resistance against abamectin, propargite, clofentezine and fenpyroximate. The mode of resistance inheritance to chlorpyrifos was found to be incompletely dominant, and not sex-linked. Non-specific esterase enzyme activity was raised from 19.35 to 33.59 mOD/min/mg proteins during the selection period and it was observed that esterase band intensities visualized by polyacrylamide gel electrophoresis increased. This study has investigated the selection of resistance to chlorpyrifos and documented resistance to abamectin, propargite, clofentezine and fenpyroximate in Turkish T. urticae. Esterase enzymes may be playing a role in chlorpyrifos resistance while glutathione S-transferase (GST) and P450 enzymes do not appear to have any significant involvement.

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Myzus persicae (Sulzer) (Hemiptera: Aphididae) is a polyphagous pest that causes significant losses in many crops. In the present study, the biochemical and molecular mechanism of acetamiprid resistance in a laboratory-selected Myzus persicae population of which the resistance ratios reached 57.5-fold were investigated. This study was conducted in the Isparta University of Applied Sciences, Agriculture Faculty, Department of Plant Protection in 2018 and 2020. Synergism, biochemical and molecular assays showed the absence of increased P450 activity in selected population. In addition, no point mutation in nicotinic acetylcholine receptor (nAChR), the target-site of neonicotinoids including acetamiprid, was detected in the selected population. These results suggests that high level of acetamiprid resistance might be developed via the mechanisms other than well-known mechanisms, such as increased P450 activity and target-site mutations. The population selected with acetamiprid showed decreased susceptibility to imidacloprid, sulfaxaflor, beta-cyfluthrin, and tau-fluvanite ranging from 1.54 to 4.76. Nonetheless, more studies are needed to support cross-resistance by Myzus persicae populations having different genetic backgrounds.

Tarımsal üretim alanlarında Tetranychid türlerinin kontrolünde öncelikli olarak kimyasal mücadele kullanılmaktadır fakat bu zararlılar ile etkin bir şekilde beslenen predatör akarlarda bu maddelerden etkilenmektedir. Bu çalışmada, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) üzerinde laboratuar koşullarında pirimicarb seleksiyon baskısı sonucu direnç, asetilkolinesteraz (AchE) enzimi ve mutasyonları arasındaki ilişkilerin belirlenmesi amaçlanmıştır. Çalışma, yaprak disk metoduyla ilaçlama kulesi kullanılarak yapılmıştır. Yedi seleksiyon sonucunda pirimicarb direnci 45.5 kata kadar artmıştır. IBP ve TPP sinerjistlerinin pirimicarb üzerinde herhangi bir etkisi belirlenememiştir. Bu sonuç AChE enziminin kinetik olarak olarak belirlenmesi ile edilen sonuçlar ile uyuşmaktadır. Başlangıç ve pirimicarb dirençli P. persimilis popülasyonlarında bakılan hedef bölge mutasyonları (F331W ve G119S) belirlenememiştir, ancak ileriki çalışmalarda farklı hedef bölge mutasyonlarının da incelenmesinin faydalı olacağı düşünülmektedir. Çalışmamız, P. persimilis'de pirimicarb direnci ve AchE nokta mutasyonları üzerinde yapılan ilk araştırma olması nedeniyle önem taşımaktadır.

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Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest that causes economic losses in many varieties of cultivated plants in the world. Wolbachia is an endosymbiont species found in many pests including mites. In pests, the mechanism underlying the interactions between insecticide resistance and endosymbiont is still not decisively understood.In this study, it was aimed to determine the relationship between spirodiclofen resistance in T. urticae and the presence of Wolbachia.Therefore, simultaneous selection of spirodiclofen was performed in both Wolbachia infected (GSS) and uninfected (GSSN) populations of T.urticae.Dry residue method was used to determine LC values in T. urticae. Bioassay experiments were applied to the larval stage of the mite. LC studies were established as 7 doses +1 control and 3 replications.Dead-alive counts were made at the end of the 7th day and resistance rates were determined. In the last selection of T. urticae with Wolbachia infection, 23-fold spirodiclofen resistance was determined, and in the last selection without Wolbachia infection, 103-fold resistance was determined.The presence of Wolbachia and frequency density were checked in both selection populations. The presence of Wolbachia was found to be quite low in all Wolbachia-uninfected selection populations compared to Wolbachia-infected populations.In addition, the relationship between spirodiclofen resistance and detoxification enzymes in mites was also investigated.As a result, it is thought that there may be a negative relationship between spirodiclofen resistance and Wolbachia endosymbiont in T. urticae, and that esterase enzyme may have an effect on the development of resistance within the scope of this relationship.