An experiment to determine the efficacy of sprays containing polysaccharides (0.025-0.2 g/L water) and/or petroleum spray oil (1.25-10 mL/L water) for control of citrus leafminer, Phyllocnistis citrella, unequivocally demonstrated that oil sprays suppress the number of mines/leaf. Oil concentrations 2 2 . 5 mL/L of water were effective, but the polysaccharides had no effect. We recommend sprays containing 2.5-5 mL oil/L. of water. The results are discussed in relation to their perceived importance in citrus integrated pest management programs and historical recommendations for the use of oils to control the pest.

The efficacies of C23 and C24 petroleum spray oils for the control of citrus leafminer were determined. Both oils significantly suppressed leafminer infestations to similar levels. Combining the C23 oil with either cupric hydroxide or copper oxychloride did not reduce its efficacy against the leafminer. The ability to mix these copper fungicides with petroleum spray oils will allow spray application costs to be reduced.