The Effect of Peach and Nectarine Host Plants on the Population Dynamics of Tetranychus urticae (Koch) (Acarina, Tetranychidae)

Abstract

The study focuses on assessing the extent of proliferation of the Tetranychus urticae mite on two peach varieties (Royal Majestic and Kaweah) and one nectarine variety (Zephyr) over a span of three years (2020, 2021, and 2022). Noticeable variations from one year to another are readily apparent. In 2020, the Royal Majestic variety recorded high infestation peaks, with 7.32 eggs per leaf, while the Kaweah variety reached 7.53 eggs, 6.87 nymphs, and 5.94 adults per leaf. In 2021, Zephyr was the most affected variety, exhibiting high populations, whereas Royal Majestic has shown reduced infestation, and Kaweah displayed the lowest infestation among the three varieties. In 2022, Royal Majestic experienced a significant infestation, with a peak of 5.83 eggs, while Zephyr showed a premature decline in proliferation following chemical treatment, with 3.53 nymphs and 3.69 adults. These annual variations underscore the variability in response of the three varieties to T. urticae infestations, while also considering various factors such as treatments, climatic conditions, and the plant characteristics. A positive correlation with thermal factors is observed.