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This study analyzed the toxicity by residual contact and the repellency effect of the essential oils of Rosmarinus officinalis, Mentha piperita, Melaleuca alternifolia, and Commiphora myrrha and their mixtures on adult females of Tetranychus urticae in laboratory and protected cultivation. The essential oil of C. myrrha exhibited a LC50 of 0.55 ml L-1, and the mixtures R. officinalis + M. piperita + M. alternifolia + C. myrrha, C. myrrha + M. piperita, and C. myrrha + M. alternifolia showed 68%, 60%, and 36% mortality, respectively. The essential oils of C. myrrha and M. alternifolia showed 95 and 70% of repellency, respectively. Mixtures of C. myrrha + M. alternifolia, C. myrrha + M. piperita, and C. myrrha + R. officinalis provided repellency of 85, 74 and 73%, respectively. Toxicity by residual contact of the essential oil of C. myrrha in protected cultivation exhibited 93% mortality, while the acaricide fenpyroximate showed 80%. The constituents of essential oils were eucalyptol (49.66%), M. piperita menthol (48.53%), M. alternifolia terpinen-4-ol (48.93%), and C. myrrha benzyl benzoate (97.71%). The essential oil of C. myrrha and the mixtures R. officinalis + M. piperita + M. alternifolia + C. myrrha and C. myrrha + M. piperita showed significant mortality. However, further studies are needed to assess the cost/benefit ratio and the effects on non-target organisms.

The Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), is an internal primary pest of stored grains of great economic importance. Few insecticides registered for fumigation control for S. zeamais exist, which makes it necessary to search for more control alternatives. Thus, the objective of this work was to assess acute toxicity, sublethal effect, survival and behavioral response of the major components of essential oils, Thymol, Camphora, Terpineol, Canpheno, Eucalyptol, Limonene, β Pinene and Eugenol; and the mixtures of these components on S. zeamais. The results showed that the mixtures of the major components caused acute toxicity, reduced survival time and offspring production, in addition to altering the behavioral activity of S. zeamais. The mixture Camphor + Canphene presented a synergistic effect, with LC50 and LC90 of 2.77 and 20.34 µl/ml, respectively. The mixtures of the major components proved to be promising products for the control of S. zeamais.

The pink mealybug, Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) is a polyphagous pest species that has been reported in about 350 species of host plants worldwide. Usually, the use of synthetic chemicals is still the most used control method for the control of agricultural pests. The objective of this present work was to evaluate the potential of the interaction of oils extracted from the species Ricinus communis L. (castor) and Jatropha curcas L. (jatropha) (Euphorbiaceae) in the form of direct and indirect application on M. hirsutus. The experiments were conducted in air-conditioned chambers at a temperature of 25 ± 1ºC, relative humidity 70% ± 10 and a photophase of 12h. The 3% concentration was used in the tests, with 11 interaction ratios between the oils. Individuals' mortality was assessed at 24, 48 and 72 hours after spraying. The results of the interactions indicated up to 78% mortality of individuals in the ratio 90% castor + 10% jatropha via indirect application, while in the direct application on individuals they presented 53% mortality in the ratio 40% castor + 60% jatropha. The interactions between castor and jatropha oils have demonstrated potential in the management of pink mealybug by direct or indirect application.

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