Insecticide trial against citrus red mite, 2024

A field trial was conducted in a 7-year-old “Tango” mandarin orchard at the Lindcove Research and Extension Center, Exeter, California to compare the effects of miticides to manage citrus red mite. The experimental design was completely randomized using 5 individual trees as replicates. Treatments were diluted in 100 gal of water per acre and were applied on 3 May using a 100-gal high-pressure D30 diaphragm pump sprayer with mechanical agitation at 250 psi. The pre- and post-treatment counts were done by counting the number of motile citrus red mites on 25 randomly selected leaves around the tree. We also counted predatory mites on 25 inner canopy leaves per tree on each evaluation date. The average numbers of citrus red mites and predatory mites per leaf were evaluated using ANOVA after Log₁₀ (x + 1) transformation with means separated according to Fisher’s Protected LSD (P < 0.05).

Before treatments, there were no significant differences in the number of citrus red mites per leaf among treatments (Table 1). All treatments, when applied with the inclusion of 1% 415 Supreme Spray Oil, significantly reduced the number of mites 1 week after treatment (1 WAT) compared to untreated check and water-only treatment. Reductions in mites were seen through 3 WAT in plots treated with Fujimite SC, and through 4 WAT in plots treated with Kodama GXP and Nealta. When 415 Supreme Oil was applied by itself, there were significant reductions in the mite population at 1 WAT, but not thereafter.

There were no significant differences in the number of predatory mites prior to treatment (Table 2). Venerate XC, Plinazolin, 415 Supreme oil, and FujiMite SC significantly reduced the number of predatory mites through 3 WAT compared to the untreated and water-only checks. At 4 WAT, the number of predatory mites in all treatments was statistically equivalent to both checks. When comparing data across citrus red mites and predatory mites, Kodama GXP and Nealta suppressed the pestiferous mites but did their predators (Tables 1 and 2).¹

Footnotes