Determination of annual population dynamics of phytophagous mite species observed in tea plants (camellia sinensis)

This thesis study was conducted over a 12-month period covering the years 2023-2024 in tea plantations located in eight regions, with four regions each in Rize and Artvin provinces. This study aimed to investigate the phytophagous mite species found on tea leaves collected from the field and to determine their annual population dynamics. For this purpose, field sampling was carried out twice a month, resulting in a total of 24 field studies. The collected mites were cleared by being kept in lactic acid solutions of varying concentrations specific to each species for morphological identification. Subsequently, they were mounted in Hoyer's medium for diagnosis. In addition to the seven mite species previously recorded in the area, nine new mite species were identified. Seven of these newly detected mites were identified at the family level, while the remaining two could only be classified at the order level. The most abundant species in the study area were Polyphagotarsonemus latus (Banks) (61.8%), Calacarus carinatus (Green) (20.3%), Brevipalpus phoenicis (Geijskes) (11.9%), Tydeus californicus (Banks) (1.9%), Neoseiulus californicus (McGregor) (0.8%), Czenspinskia transversostriata (Oudemans) (2.3%), and Tuckerella japonica (Ehara) (0.1%). Additionally, nine unidentified mite species collectively accounted for 0.7% of the population. The most abundant species, P. latus, was observed on tea plants throughout the year except in March, with its population peaking in August. Statistically significant differences were found between provinces, regions, and months. Correlation analysis with temperature, humidity, and precipitation parameters indicated that increasing temperatures had a positive effect on the P. latus population. The second most abundant species, C. carinatus, began to increase in January, peaked in March, and reached low levels starting from May. Statistically significant differences were also detected between cities and regions. Temperature was found to have a moderately negative effect on the C. carinatus population. The third most abundant species, B. phoenicis, was observed on tea plants throughout the year, with population peaks occurring in November and December, while very low levels were recorded in other months. Statistically significant differences were found between provinces, regions, and months for this species as well. The population level of B. phoenicis showed a moderate negative correlation with humidity and a moderate positive correlation with precipitation. Other phytophagous mite species identified on tea leaves generally exhibited positive correlations with temperature and humidity, and negative correlations with precipitation. The predatory mite N. californicus showed weak negative correlations with temperature and humidity, and a positive correlation with precipitation. Determining the population dynamics of the mite species identified in the area and conducting continuous surveillance studies are essential for tea cultivation and other economically important crops in the region. Investigating the potential interactions between phytophagous mites and their predatory counterparts is also of significant importance for plant protection strategies.