Control of Fuller Rose Beetle in Pruned and Unpruned Citrus, 1986

Pesticides were evaluated for control of adult Fuller rose beetle (FRB) in a 51-year old grapefruit grove in Corona, CA. The grove was divided into 4-row blocks in which the tree skirts were alternately pruned to a 4 foot height or left unpruned over the period 15-30 Jul, prior to the application of treatments on 31 Jul. Two adjacent blocks were chosen for the pesticide trial, one skirt-pruned and the other non-pruned. Prior to skirt pruning, 5 fruit on each tree in the center 2 rows of each block were sampled for the presence of FRB egg masses under the calyx and treatments were assigned to 4-tree plots (2 x 2, within the center 2 rows of a block) based on the number of fruit infested. Each treatment was replicated in 3 plots in both the pruned and unpruned block (24 trees total). The control (untreated) was replicated in 6 plots in both blocks. Treatments were applied using a hand-gun at 450 psi, to the trunk of skirt-pruned trees (ca. 1 gal per tree), and using outside coverage to the lower 6 ft of the canopy and trunk in unpruned trees (ca. 3 gal per tree). Posttreatment counts of the number of live beetles per plot were taken by shaking foliage above a 3 x 4 ft beating cloth laid below the outside canopy in 2 random quadrants per tree (8 per plot). FRB adult emergence from the ground was monitored using ground traps in 2 adjacent untreated blocks (1 skirt-pruned, 1 not) over the period of the trial.