Effects of miticide treatments on citrus red mite, 2023

A field trial was conducted in a 6-year-old ‘Tango’ mandarin orchard at the Lindcove Research and Extension Center, Exeter, California to compare the effects of 1% 415 oil used alone and in combination with 4 miticides citrus red mite density. Five miticide treatments and an untreated control were replicated 6 times in a CRD using individual trees as replicates (Table 1). Treatments were applied at 250 psi and 200 gpa using a multi-chambered high-pressure D50 diaphragm pump sprayer with mechanical agitation on 7 June 2023. The trial was evaluated weekly for 4 weeks by counting the number of motile citrus red mites on 25 leaves on the periphery of each tree. The average numbers of citrus red mites per leaf were compared between treatments using one-way ANOVA after log (x + 1) transformation of the data. Treatment means were separated according to Fisher’s protected LSD (P < 0.05).

Oil alone or in combination with Fujimite SC, GXP-70100, and Veto 30 SC, significantly reduced the number of citrus red mites per leaf up to 4 WAT, compared to the untreated control (Table 1). Citrus red mite densities in plots treated with Fujimite SC, GXP-70100, Veto 30 SC, and oil were significantly lower compared to untreated control, oil only, and Venerate SC with oil. Our results show that adding a miticide to oil significantly reduced the number of mites compared to oil alone for Fujimite SC and Veto 30 SC in week 3 and for GXP-70100 on the final evaluation date. Citrus red mite densities in plots treated with Venerate XC and oil were significantly higher or equivalent to the oil alone on all evaluation dates. Mite densities in plots treated with oil and Fujimite SC, GXP-70100, or Veto 30 SC consistently had the lowest mite densities across all evaluation dates.¹

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