Biological characteristics of eutetranychus orientalis (Klein) (Acari: Tetranychidae) on different citrus species and the effectiveness of two phytoseiidae species on pest and its prevalence in citrus orchards in Adana

In this study, it was aimed to determine the prevalence and infestation rate of the Citrus brown mite Eutetranychus orientalis (Klein) (Acari: Tetranychidae) in intensive citrus growing areas of Adana as well as the population development of the pest in four different citrus orchards; the biological characteristics of the pest on four different citrus species (Lemon-Meyer, Orange-Washington Navel, Mandarin-Okitsu and Grapefruit-Star Ruby); and the biological characteristics, functional and numerical responses of Amblyseius swirskii Athias-Henriot and Euseius scutalis (Athias-Hemriot) to the pest. As a result of surveys, E. orientalis and Panonychus citri (McGregor) infestation rates were found to be 20% and 34.21%, respectively. Among citrus species, E. orientalis infestation rate was determined 33.84% in lemons, 33.33% in oranges and 8.69% in mandarines, while no pest was found in grapefruit orchards. In all citrus areas where the population development of E. orientalis was carried out between 2019 and 2022, it was observed that the pest generally started to build up a population in August-September, reached the highest levels in November-December, and decreased in February-March. P. citri showed a low level of population development on lemon and orange but not on sour orange. The immature development times of female and male of E. orientalis was determined as 13.77, 14.18, 14.33, 15.00 days and 12.67, 12.90, 13.41, 13.59 for lemon, orange, mandarin and grapefruit, respectively.The total adult life span of the pest was determined to be 13.06, 11.10, 10.77 and 11.50 days, respectively. The number of eggs laid by E. orientalis throughout lifespan and daily were 29.78 and 3.08, 24.92 and 3.20, 15.92 and 2.08, 17.48 and 2.31 for the same hosts. The developmental periods of the immature stages of A. swirskii and E. scutalis females feeding on E. orientalis were recorded as 7.24 and 7.45 days, respectively, while the corresponding periods for males were 7.02 and 6.54 days. Total adult lifespan of female was determined as 25.92 and 25.15 days; total number of eggs laid by predatory mites throughout their lifetime and daily egg numbers were 43.16 and 31.85 and 2.09 and 1.59. Both A. swirskii and E. scutalis exhibited a Type II functional response curve when their predation rate was assessed as a function of increasing prey density on E. orientalis.