Control Methods for Citrus Red Spider Mites and Rust Mites Damaging Fruit

    Citrus red spider mites and rust mites are among the major pests in citrus-producing areas, with two peaks a year, in spring and autumn. According to production observations, when the autumn temperature is about 20°C, red spider mites break out heavily; if early control is not done properly, red spider mites will again reach a damage peak from late August to October.

Citrus red spider mite

    To control citrus red spider mites and rust mites, pay attention to the following points: First, do a good job of early control. Autumn control of red spider mites and rust mites is the key to ensuring high-quality citrus production. Spraying an acaricide once in August can control the damage of red spider mites and also control the damage of rust mites to the fruit surface. In September to October, before the second peak of red spider mites, spray an acaricide 1~2 times to control both pests at once.

    Second, use the following indicators as a reference for spraying. When there are 10~12 red spider mites on each citrus leaf in autumn; for rust mites, take 20 leaves or young fruits from the upper, middle and lower parts of the canopy of each citrus tree, and examine them carefully with a magnifying glass. When there are mites on 20% of the leaves or citrus fruits, spray immediately. A visual method can also be used: when there is a thin, dust-like substance on the citrus or leaves (the cast skins of nymphs), it indicates a high pest population density, and spraying is needed for control.

    Third, choose acaricides reasonably. To control red spider mites: crystal lime sulfur mixture (do not use home-boiled lime sulfur mixture) at 150 times dilution, or 20% clofentezine at 3000 times dilution, 40% propargite at 2000~3000 times dilution, pyridaben at 4000~5000 times dilution, etc. In addition, a homemade pesticide mixture of urea and washing powder, prepared by adding 1 kg of washing powder to 400~600 kg of water and then adding 0.5~1 kg of urea, mixed evenly before spraying; 1~2 days after spraying, the control effect can reach about 90%. To control rust mites, use: Mancozeb M~45 (that is, 80% mancozeb wettable powder) at 600 times dilution, which controls rust mites for as long as 30~60 days and also controls citrus sooty mold. New-type mineral oil emulsion (Lüying) at 150~250 times dilution; 20% fenpropathrin at 3000~4000 times dilution, 65% zineb at 500 times dilution; or 73% propargite at 1500 times dilution, all have very good miticidal effects on rust mites.