Insecticides for Citrus Leafminer Control, 2014 *

A field trial to determine the efficacy of insecticides to protect citrus foliage against citrus leafminers was conducted in a 3-yr-old orchard of “Tango” mandarins at the Lindcove Research and Extension Center, Exeter, California. Sample trees were pruned on 18 August 2014 to stimulate new flush. Insecticides were applied to eight trees per treatment in a CRD using a 100 gal high pressure D30 diaphragm pump sprayer with mechanical agitation at 200 psi. Treatments were applied in 100 gpa water on 18 September. All treatments were applied with 0.50% Omni 6E oil, except one treatment of Agri-Flex which was applied with Widespread Max at 0.03%. Four to ten young flush leaves that could be utilized by citrus leafminer larvae were collected from four branches per tree and examined under a dissection microscope at weekly intervals during October. The mean number of live larvae per suitable leaf was compared between treatments using ANOVA and the means were separated according to the LSD test ( P  = 0.05) after log ₁₀ (x + 1) transformation.

All treatments significantly reduced the mean number of larvae per suitable leaf on two or more dates 1–3 wk post treatment ( Table 1 ). By wk 4 post treatment, Voliam Flexi was the only treatment to show significant reduction of the larvae per leaf compared to the untreated check.

Author notes