Gerbera jamesoni L., Asteraceae, is an ornamental cut flower native to South Africa. It is a perennial plant with a variety of colors. The two-spotted spider mite Tetranychus urticae Koch is an important insect pest that causes economic damage and reduces the marketability of Gerbera. First, three vegetable oils: neem oil, marig old, and castor oil (Dayabon®) and the acaricide cyflumetofene (Danisarba®) were bioassayed on the spider mite on the back of gerbera leaf cuttings. Then, the synergistic effects of the oils on the acaricide cyflumetofene were evaluated.Finally, a supplementary experiment compared the release of zero, 45, 50, and 55 predatory mites Amblyseius swirskii, (Acari: Phytoseidae), predator mite per square meter in a gerbera greenhouse with the selected treatment of oil mixed with acaricide.The results of bioassay of the compounds showed that in the three stages of eggs, nymphs and adult mites, neem oil with LC50 of 1549, 1261 and 1098 ppm had the highest lethality among the oils, and the LC50 of cyflumetofene with LC50 of 331, 272 and 224 ppm for eggs, nymphs and adult mites showed more mortality than the oils. The mortality effect of cyflumetofene mixed with neem oil had synergy rates of 3.23, 3.12 and 3.36 on eggs, nymphs and adult mites, respectively, which confirms the synergy of oil on the poison. Therefore, the method of integrating the application of a mixture of cyflumethophene (SC 20%), 0.8 ml.L-1 with 0.7 ml.L-1 neem oil with the release of 50 predatory mites of A. swirskii had the most effect on reducing the spider mite on gerbera, which is recommended as an appropriate control method and for continuity of control, the ability to release A. swirskii predatory mite should be repeated monthly.
The bioassay results of the compounds showed that neem oil with LC50 of 1549, 1261 and 1098 p.p.m. Neem had the highest killing power among oils, and the LC50 of cyflomethofen was 331, 272 and 224 p.p.m. For eggs, nymphs and adult mites, it showed more mortality than all oils.And the LC50 of cyflomethofen mixed with neem oil had a synergistic effect of 3.23, 3.12, and 3.36 p.p.m. on eggs, nymphs, and adult mites, respectively. Therefore, the integrated method of using a mixture of cyflomethofen (SC 20%), 0.8 ml.L-1 with neem oil 0.7 ml.L-1 with the release of 50 predatory mites A. swirskii had the greatest effect in reducing the spider mite on gerbera. which is recommended as a suitable control method. To continue to control release of predatory mite A. swirskii should be repeated monthly.
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