Spatiotemporal Dynamics of Greenhouse Whitefly, <i>Trialeurodes vaporariorum</i> , and Its Parasitoids, <i>Encarsia formosa</i> Gahan and <i>E. sophia</i> Girault &amp; Dodd on Cucumber

A study investigated the spatiotemporal dynamics of greenhouse whitefly, Trialeurodesvaporariorum (Westwood), and its parasitoids ( Encarsia formosa Gahan and E. sophia Girault &amp; Dodd) on cucumber crops in Himachal Pradesh, India, during April–July of 2022 and 2023. The research aimed to understand colonization patterns of greenhouse whitefly invasion due to protected cultivation expansion and climate change. In 2022, greenhouse whitefly populations emerged in the 19th standard meterological week (SMW) (0.36 nymphs/leaf), peaking at 57.47 nymphs/plant in the 28th week. The 2023 season showed higher infestation levels, with initial detection in week 21 (1.02 nymphs/leaf) and peak density of 127.76 nymphs/leaf in week 30. The parasitoid E. formosa appeared in week 21 (2022) and week 23 (2023), reaching peak parasitism of 19.04 and 19.23 nymphs/plant, respectively. Similarly, E. sophia emerged later, showing peak parasitism of 11.34 nymphs/plant (week 29, 2022) and 6.85 nymphs/plant (week 32, 2023). Optimal sampling analysis revealed an inverse relationship between pest density and required sample size, with low densities requiring ≈584 samples to achieve 10% precision. The findings of this investigation provide valuable empirical data for establishing an efficient sampling protocol for T. vaporariorum and its associated parasitoids, E. formosa and E. sophia , in cucumber cultivation systems.