Zum Massenwechsel der SpinnmilbeTetranychus cinnabarinus (Boisd.) und der RaubmilbeAmblyseius gossypii (Elbadry) auf Baumwolle

Abstract

Population dynamics of Tetranychus cinnabarinus (Boisd.) and Amblyseius gossypii (Elbadry) (Acari) on cotton plants

Population dynamics of spider mites and predators on cotton plants were influenced by the date of cotton plantation. The plantation of cotton in October–November led to earlier and higher infestation of cotton leaves with spider mites than that of cotton planted in March. Similar magnitude of predatory mite infestation was observed in the cotton planted either October–November or in March. However, another lower peak of predatory mite population was recorded during May in the cotton planted in October–November. Spider mite populationl decreased gradually when predatory mite population increased rapidly on cotton leaves during August regardless to the date of cotton plantation. Chemical control of tetranychid mites on cotton plants should be applied by the first week of July to encounter population outbreaks which arise by the end of July and during August.