Determination of the distribution, population fluctuation and damage of Tuckerella japonica (Acari: Tuckerellidae) in tea plantations of the Eastern Black Sea Region, Turkey

Camellia sinensis (Theales: Theaceae), tea, is an evergreen shrub or small tree. Tuckerella japonica (Trombidiformes: Tuckerellidae) is a pest mite species on a variety of agricultural crops including tea. This study was conducted to determine the distribution, population, and damage of T. japonica in tea plantations of the Eastern Black Sea Region, Turkey. Surveys were conducted to determine the mite's distribution in the tea gardens of Artvin, Giresun, Ordu, Rize, and Trabzon provinces. 205 tea plantations in 32 districts in the region were sampled in 2021-2023. The population of T. japonica was also determined on the Turkish tea clone "Muradiye10" and the Japanese tea clones "Samidori" and "Saekari" in Rize in 2022-2023. The effect of mite feeding on the physicochemical and chlorophyll content of tea leaves as well as its cellular injury to the tea stem were determined. As a result, T. japonica was detected in all sampled provinces except Ordu. It has been determined that the population of mites generally reaches its peaks in July-Agust and October in Rize province. The results show that mite feeding at densities of 1, 5, 10, and 15 mite/plant for 45 days did not affect leaf chlorophyll content. However, at the same densities and durations, a decrease in leaf total polyphenol, water extract, caffeine, and total ash content was observed, along with an increase in dry matter and crude cellulose content. Additionally, T. japonica feeding caused varying levels of damage in tea branches including the formation of lignin and suberin in the wall of cell, cellular collapse and cell division.