Scale insects are one of the pests in the garden . Their sticky traces are a sure sign that it is an infestation. How you can fight the scale insects and what home remedies help against them, we explain in the article.
Table of contents
- 1. recognize scale insects: What do scale insects look like?
- 2.how to fight scale insects: which garden and house plants are infested?
- 3. what helps against scale insects? Home remedies and beneficial insects
- 3.1. beneficial insects against scale insects
- 3.2. fighting scale insects: home remedies with soft soap
- 3.3. fight scale insects with dishwashing liquid
- 3.4 Is neem oil effective against scale insects?
- 3.5. orange oil against scale insects
- 3.6. fight scale insects with canola oil
- 3.7. fight scale insects with coffee: is it possible?
1. recognize scale insects: What do scale insects look like?
The scale insect species that can be found in Germany have a body length of 0.8 mm to 6 mm. The males have wings and look like small flies. The females, on the other hand, are mostly immobile and spend their entire life on the plant. They feed from the plant juices, which they ingest through their mouthparts. They are yellow-brown in color and lay their eggs directly on the plant. The larvae, which hatch in mid-summer, are motile and also feed on the plant juices. In the process, they secrete honeydew that attracts ants.
1.1.How to recognize a scale infestation?
The first sign of an infestation is the sticky secretion found on the underside of plant leaves, shoots or twigs. The leaves of the infested plant are shiny and stick together. In some cases, the flowers may wither and the leaves turn yellowish. Honeydew, this sticky substance produced by the adult females, is found not only on the plants themselves, but also on furniture and the ground. Ants are often attracted to it, as the honeydew is the perfect food for them. By the way, the scale insects can easily overwinter both indoors and outdoors. They are protected from the weather by a shell.
1.2.How do scale insects get into the apartment?
How scale insects spread in the garden has long been known to garden experts. There, mainly the mobile larvae are carried away by the wind. Some larvae simply migrate and look for other plants. With a hot summer and mild autumn, several generations can grow. This is also the reason why in the course of only one gardening season, they can infest all the plants in the bed.
But many people wonder how the pests get into the apartment. There are several variants:
- Most often, the scale insects are transported with a new plant. So when buying new plants, always check the underside of the leaves for scale insects.
- The larvae can also be brought in with the plant soil. Yes, scale insects can also be found in the soil. The reason for this is quite simple. Some scale insects infest the plant roots. Their larvae stay in the plant substrate because of this.
- Ants can also contribute to the spread of scale insects. They often take the larvae to new plants.
1.3 Are scale insects dangerous for humans?
Scale insects are usually not dangerous to humans. The most important thing is to control the pests naturally and avoid using chemicals. The majority of these chemicals are harmful to humans and animals, and there are preparations that are even banned because they can penetrate into the groundwater. Those who violate the rules have to face fines. Fortunately, you can avoid it, because there are also home remedies or means of natural control, with which you can drive away the pests.
2. fight scale insects: what garden and houseplants are affected?
Scale insects are very adaptable. While outdoor pests spread during the summer months, houseplants are mostly infested during the cold season. It is enough if only one potted plant with scale insects is brought into the greenhouse or conservatory. Therefore, the first step to control scale insects is prevention. Check regularly to make sure all houseplants are healthy. Possible reasons why a plant is infested with scale insects:
1. the plant is weakened. Possible reasons: Incorrect location, insufficient care, too much fertilizer with nitrogen.
2. the winter quarters are too warm. This can promote the spread of larvae and the reproduction of scale insects. Place your houseplants in a bright and cool place.
3. sunlight is not sufficient. This will cause the plant sap to change and be preferred by the scale insects.
2.1 Scale insects on lemon tree
Lemon trees are often infested by scale insects. This is mainly due to the fact that they are often placed in the wrong place. Especially in winter, too warm and too dark winter quarters can weaken the tree. Basically, there are two variants for wintering to choose from:
1. wintering in a warm and very bright location (the winter garden, a room with large windows and south or west exposure). Temperatures should never fall below 20° Celsius. If the lemon tree is not wintered in the dark, then it also needs regular fertilizing in the winter.
2. overwinter cool and dark (in a garden shed or a bright garage). Here, the temperature in the room should be between 4 ° and 14 ° Celsius. Very important here: put the plants on a polystyrene plate, so that the roots do not freeze and can absorb moisture.
No matter which option you choose, the humidity should be around 40%. If you ventilate the room even on warm autumn and winter days, then the citrus tree will feel comfortable and survive the winter in good health.
In case of a light infestation: scrape off the pests with a toothbrush, repot while thoroughly rinsing the roots to remove any remaining larvae. Be sure to overwinter the infested plant separately from other houseplants.
If the infestation is severe: place in a sunny location, scrape off the pests and repot the plant. Ventilate regularly and do not apply nitrogen fertilizer to the tree. For home remedies and beneficial insects that help against scale insects, see below.
Home remedies: spray with canola oil or with orange oil.
2.2 Scale insects on palms
On diseased palms, pests spread quickly. Also in this case: overwinter the plant in a dark and cool place with suitable humidity. In this case, the composition of the plant juices remains unchanged, and the exotic is less attractive to aphids . By the way, if you have a lot of palms, you should leave enough space between the tubs.
In case of a light infestation: scrape off the scale insects, repot, rinse the roots under running water.
In case of heavy infestation, place the palm tree in a sunny place with high humidity. For home remedies and beneficial insects that help against scale insects, see below.
Home remedies: washing-up liquid solution and soft soap
2.3 Scale insects on the olive tree
The olive tree is often infested by pests because it is often not properly cared for. In case of light infestation, it is enough to scrape off the scale insects and strengthen the container plant with mycorrhizal fungi. The fungal spores are sold as a substrate and must be buried near the roots of the plant. This soil fungus can improve nutrient absorption and regulate the composition of plant juices. This strengthens the olive tree.
If the infestation is severe, pruning can help, cutting off only the infested parts of the plant. Then you can treat the tree with a home remedy.
Home remedy: solution with soft soap (see below).
2.4 Scale insects on the oleander
The oleander is very sensitive and can die quickly. To prevent this, check the houseplants regularly for pests. Often it is enough to remove the scale insects with a toothbrush. If the pests have spread, pruning can help.
Home remedy: You can treat the plant with a homemade spray with orange oil. (see below)
2.5 Control scale insects on orchids
If your orchids have scale insects, then you should act as soon as possible before the pests spread. Proceed as follows: First, scrape off the scale insects with a toothbrush, then cut off the bracts of the affected flowers. Then you can treat the remaining orchid leaves, shoots and stems with a home remedy.
Suitable home remedy: orange oil
2.6 Fighting scale insects on hydrangeas
If you want to control scale insects on hydrangeas, then you can take the following measures:
1. loosen the soil around the plant roots.
3. if the infestation is heavy, you can control the scale insects with beneficial insects.
3. What helps against scale insects? Home remedies and beneficial insects
If you want to control scale insects, then you can drive them away with beneficial insects or you can treat the plants with home remedies. In the following we will take a closer look at the different options.
3.1 Beneficial insects against scale insects
Scale insects not only infest ornamental plants, but can also cause great damage in the kitchen garden. So if you find the pests in the garden, then you should act quickly. You can control the scale insects naturally by establishing beneficial insects in your home garden. The following insects will help:
- ichneumon flies against cup scale insects.
- CM-Australian ladybugs against mealybugs
- Ladybugs against lidded scale aphids
- (Earwigs help against aphids, but they do not belong to the superfamily of scale insects).
- Some bird species
A naturally designed garden provides the best conditions for a wide variety of species. However, monocultures and gardens with only a few plant species can prove to be a real challenge. In this case, you can also find certain beneficial insects in garden centers. However, in order to find the appropriate beneficial insect to feed on the larvae and adult males and females, you should bring a specimen of your scale insects to a professional.
3.2 Fighting scale insects: home remedy with soft soap
An effective home remedy for scale insects is a solution of soft soap and mineral spirits. Fill 2 liters of water into a plastic container, add 30 ml of soft soap and 30 ml of spirit and let the solution sit for about half an hour to 45 minutes. Apply the solution to the leaves and shoots with a brush. It is worth testing the effect on the plant first on one leaf. If the next day the leaf is not yellowed and falls off, then you can use it to treat the plant.
Important: A second treatment is done about 10 to 14 days after the first. Never use on orchids or oleanders.
3.3. control scale insects with dishwashing liquid
Dishwashing detergent alone can not do much against scale insects. But the combination of an oil and dishwashing liquid can prove to be particularly effective. If you want to fight the scale insects naturally, then you can add 1 tablespoon of vegetable oil (olive oil works well for this purpose, but you can also use canola oil) and 1/2 teaspoon of dishwashing liquid to 500 ml of lukewarm water. Stir the solution well and pour it into a clean spray bottle. Wet the plant leaves (including the underside) with it.
3.4 Is neem oil effective against scale insects?
Neem oil, which is extracted from the neem tree, is considered a biological poison for insects . However, it is not very effective against scale insects, because they have a shell.
3.5 Orange oil against scale insects
The orange oil is very aggressive and quickly unfolds its effect. It has another significant advantage: unlike various other brews, it has no unpleasant odor and is also suitable for use indoors. Add about 10 ml of orange oil to 500 ml of lukewarm water, pour the solution into a spray bottle and shake the bottle vigorously. After that, test its effect on a leaf. If this does not die, then the next day you can spray the whole plant. It is more gentle if you brush the scale insects with the solution.
3.6 Control scale insects with canola oil
Rapeseed oil is gentler than orange oil and has a similar effect: when the plant is treated with it, the scale insects cannot breathe and suffocate. To ensure that the larvae are also controlled, you should treat the plant again after a week.
3.7 Control scale insects with coffee: is it possible?
The aphids can be effectively controlled with home remedies with coffee grounds, because the caffeine contained in them is toxic to them. However, the scale insects have a shell and therefore are less susceptible or not susceptible at all. But you can brew the coffee grounds, strain them and use the water to water the plants. The scale insects will absorb the caffeine through the plant juices.