Silvery-white sucking traces, growth disturbances and wilted leaves of your houseplants are indications of an infestation with thrips. The sucking insects are particularly common in dry heating conditions. In this article, you will learn how to combat thrips – without the use of chemicals. Thunderbugs, blisterfoots, fringewings … Thrips (scientifically known as Thysanoptera) have many names. Over 5000 species exist worldwide. Even the 200 species native to our region are enough to really mix up your “urban jungle”. The insects, which are one to three millimeters in size, feed on the cell sap of plants.
First aid: Shower and separate As a first aid measure in case of thrips infestation, it helps to separate the affected plant from other green plants and shower it off. Try to make sure that the water does not get into the soil. You can, for example, pull a plastic bag over the pot and prevent the thrips from landing in the substrate.
Catching thrips with blue panels It is possible to fight thrips as well as fungus gnats with adhesive insect traps. Blue panels are the method of choice, because thrips are magically attracted to the color blue. You can make your own blue boards using the same principle as reusable yellow boards and save on waste. Tip: Please do not use glue boards outdoors, because there is a risk that birds and other beneficial insects will get caught in them.
Spray cures against thrips: olive oil, garlic decoction and neem oil A decoction of onions or garlic helps against many pests and plant diseases: Simply pour three finely chopped cloves of garlic or half an onion over a liter of boiling water and let it steep covered overnight. Spray the infested plants with the strained decoction and water. Like other pests, thrips are particularly sensitive to oil. A mixture of two tablespoons of cooking oil, a drop of organic hand dishwashing detergent and a liter of water can be used to spray robust, large-leafed plants (e.g., monstera, palms and ivy). Tip: The oil of the neem tree (so-called neem or neem oil) is known for its insecticidal effect. It prevents larvae from developing into adult insects. You can make an emulsion of it as you would with cooking oil and spray the plants with it.
Beneficial insects against thrips: predatory mites and lacewings Indoors, natural enemies of thrips are a good way to get the pests under control. You can obtain predatory mites, lacewing larvae and nematodes from specialty stores, garden centers and online stores, which are then applied to the plant or substrate according to the dealer’s instructions. After two to three weeks, the thrips infestation should be gone.
Preventing thrips To prevent thrips infestation in the first place, there are a few things you can consider around your houseplants, because beautiful, strong houseplants grow without chemical helpers. Spray plants Thrips thrive in dry conditions. Therefore, spray your plants regularly with lime-free tap water or collected rainwater. In this way you create a moist environment. Also, regular washing down of plants will counteract thrips and other pests, as well as house dust buildup.