Scale insects (Coccoidea) are small insects and are among the most common plant pests on houseplants and garden plants. They feed on the sap of their host plant, thereby removing valuable nutrients from it.
characteristics
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Appearance : shield-shaped insects
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Size : varies between 0.5 and 3.5 centimeters depending on the species
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Color: mostly brownish to orange-black
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Special features: Females have almost legless, oval bodies, which are protected by a round shield on the back.
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Immobility : Due to their shield, female scale insects are largely immobile.
Detecting scale insect infestation
You can recognize an infestation of scale insects by the closely packed creatures that form a kind of thick crust on leaves and stems. Scale insects are mainly found on the undersides of leaves and leaf stalks, where the affected areas fade or turn yellow. The damage to the plant is evident in yellowed, deformed leaves and, in the case of a severe infestation, in an overall weakened plant. Other typical symptoms are a sticky, shiny coating (honeydew) on the leaves and an increased number of ants.
Fighting scale insects: How it works
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Isolation : To control scale insects, first isolate the affected plants so that the infestation does not spread to other plants.
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Removing scale insects : The adult insects can be scraped off the plant, e.g. with a damp cloth or an old toothbrush.
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Spray the plant : To ensure that you also catch the larvae, you should spray the plant – with pesticides or oil mixtures.
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Cutting : If the infestation is severe, cut off affected parts of the plant.
Home remedies against scale insects
If you don't want to use chemical insecticides, natural remedies offer an effective alternative for controlling scale insects. Mix 250 ml of a suitable oil (e.g. rapeseed oil, olive oil or neem oil) with 1 litre of water and spray the solution onto the affected plants. Alternatively, you can make a soap solution from 1 litre of water and 15 ml of soap and spray the plant with it. Both methods work by blocking the scale insects' airways so that they suffocate. You should avoid common tips on how to control scale insects with coffee. On the one hand, this method is ineffective due to the pests' protective shield, and on the other hand, the photosynthesis of the plants can be impaired.
Preventing Scale Insect Infestation
Scale insects are harmless to humans, but can cause significant damage to plants. Infestations can be effectively prevented by taking targeted measures and avoiding favorable conditions for the pests.
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Increase the humidity : Scale insects prefer dry, warm air. The dry air from heated rooms in winter in particular creates ideal conditions for their spread on houseplants.
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Optimize the location: Avoid drafts, as wind can encourage the spread of scale insects indoors. Also make sure that plants do not come into contact with pets, clothing or other plants.
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Strengthen the plant : Healthy and strong plants are less susceptible to pests. A balanced supply of nutrients, especially avoiding excess lime in the soil, contributes to the vitality of the plant.
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Regular inspection : Check your plants regularly to detect and control pest infestations early.
