Determination of the population densities of harmful mite species and predators in vegetable areas, and some biological parameters of Neoseiulus barkeri hughes (Acari: Phytoseiidae) in Diyarbakır, Elazığ, and Muş provinces

This study was carried out in between 2018-2020 on Capsicum annuum L. (Solanales: Solanaceae), Cucumis sativus L. (Cucurbitales: Cucurbitaceae), Cucumis melo L. (Cucurbitales: Cucurbitaceae), Cucurbita pepo L. (Cucurbitales: Cucurbitaceae), Citrullus lanatus (Thunb.) Matsum. & Nakai (Cucurbitales: Cucurbitaceae), Solanum melongena L. (Solanales: Solanaceae), Solanum lycopersicum L. (Solanales: Solanaceae) and Phaseolus vulgaris (Fabales: Fabaceae) fields in Diyarbakır (Bismil, Çermik, Çınar, Eğil, Ergani, Sur and Yenişehir districts), Elazığ (Baskil, Maden, Sivrice and Central districts) and Muş (Hasköy, Korkut and Central districts) provinces. In vegetable production, mites are an important polyphagous insect in our country as well as in all other countries. With this study, the significant mite species and their predators were determined in vegetable areas. In 2018, a total of 646 plant samples were sampled and 479 of these samples were observed with mites. C. sativus among these plants was the most contaminated culture plant with a rate of 95,31%. The least contaminated plant was indicated as C. annuum with the rate of 30,48%. In 2019, 417 plant samples were studied totally, and 197 of them were observed with mites. C. pepo among these plants was the most contaminated cultivar with a rate of 72,34%. On the other hand, the least contaminated plant was C. sativus with a rate of 30,98%. The contamination rates can occur as significant differences according to studied years. The studies we conducted for following population dynamic of Tetranychus urticae Koch. (Acari: Tetranychidae); the relationship between population dynamic and predators was studied in two different eggplant fields located in Sur and Çınar districts in 2018 and 2019 time intervals. In 2018 and 2019, it was observed that the population ascent of T. urticae was observed in June and it was reached the highest level of population in July. And then the population of these two-spotted spider mites started to decrease in September. The acaricide application and fertilization processes are carried out during the season in the Çınar experimental area. As a result of the observation, only one individual spider mite was observed for two eggplant leaves. The reason for this small number of individuals was considered that the population starts over after acaricide application and it grows until other chemical applications. The population has never reached the economic loss threshold in that field. As a result of survey study to reveal mite species and their predators shows that 10 species belonging to the Phytoseiidae family; 5 genera belonging to Erythraeidae family; 3 species belonging to Tetranychidae family; One species belonging to Cheyletidae, Iolinidae, Tarsenomidae, Acaridae, Nanorchestidae families were found. There are species whose diagnosis has not been completed due to the pandemic, belonging to the families of Ameroseiidae, Tydeidae, Stigmaeidae, Parasitidae, Bdellidae, Bryobinae, Eriophyidae, and Cunaxidae. The many predatory insects were identified as 3 of them from the Anthocoridae family; 7 of them from the Miridae family; 2 of them from the Nabidae family; 1 of them from the Geocoridae family; 1 of them from the Chrysopidae family; 9 of them from the Coccinellidae family. And also three predators feeding on T. urticae were identified in the Aeolothripidae family. While Neoseiulus barkeri Hughes (Acari: Phytoseiidae) is the most common species among predatory mites, T. urticae is the most common mite species. The capacity of prey consumption of N. barkeri on T. urticae was studied in a growth chamber at 25±1 ºC, 65±5% humidity, 16 h dark and 8 h light period. The pray consumption capacity of N. barkeri feeds on T. urticae was revealed with this study. The consumption capacity of N. barkeri was determined as 14,59 eggs, 11,16 larvae, 10,61 protonymph, 8,58 deutonymph, and 5,76 adults during the oviposition period. In addition, molecular studies of N. barkeri were carried out and phylogenetic tree analysis was revealed by DNA extraction and sequencing from the one individual mite. The contamination rates can occur as significant differences according to studied years.