Safe Control Methods of Eutetranychus orientalis (Klein) Infested Navel Orange Trees at Menoufia Governorate, Egypt

Abstract

Citrus brown mite, Eutetranychus orientalis (Klein), is one of the most serious pests on fruit, vegetable and ornamental plants in the world. The present study aimed to evaluate the toxicity, and the repellency/attractancy effects of five essential oils (clove, castor, cinnamon, black cumin and anise) on E. orientalis under laboratory conditions. Also, field experiments were performed to investigate the efficacy of two essential oils (castor oil and black cumin 10 %), compared with other acaricides and predacious mites. Two acaricides (abamectin 5 % EC [Biomectin™] and fenpyroximate 5 % SC [Ortus ]), in addition to the predacious mites Phytoseiulus persimilis and Euseius scutalis, applied at two levels of release (200 and 300 individuals/tree). The results showed that after 1 h of the treatment, essential oils of black cumin and anise recorded the highest percentage of repellency (80–100 %) followed by castor oil (30–90 %), and clove oil (50 and 70 %), while cinnamon was the lowest. In addition, castor oil showed good repellency effect after 6 h, while black cumin has the same effect after 1 h of application. Field experiments revealed that castor oil gave the best efficacy in suppressing E. orientalis population compared with control, followed by black cumin oil. While applying the acaricides fenpyroximate and abamectin recorded good reduction of E. orientalis with mortality of 88.85 and 87.92 %, respectively. The numbers of E. orientalis were affected by releasing the biological control agent P. persimilis at 200 and 300 individuals/tree, where the numbers of E. orientalis decreased on trees to 1.5, 1.0 indiv./10 leaves after 15 days of release compared with pre-treatment account 3.0, 2.5 indiv./10 leaves, respectively.