The aphid sucks the sap from the plants, weakening them. The damaged areas on the plant epidermis also allow pathogens to penetrate, which is why you should get rid of the lice quickly.
Common native species
There are around 850 species of aphids that are native to Europe alone. Some of them specialize in certain plants, such as the bean louse on beans and other legumes. For hobby gardeners, the species that belong to the family of the tube aphids are particularly problematic (Aphidoidea) are located. They mainly attack fruit and vegetables as well as occasionally flowers or Ornamental shrubs in the garden. The coloration of the aphid species often varies depending on their food sources or Living conditions and there are also yellow, black and red species in addition to green.
Pea aphid (Acyrthosiphon pisum)
- Size: 2 - 4 mm
- Colour: green to yellowish (rarely reddish)
- airworthy
- Damage: Host plants are deprived of important nutrients; Carrier of viruses with leaf roll and mosaic symptoms
The greenish to yellow pea louse can be found on a wide variety of legumes. In addition to peas, it is often found on broad beans or lentils. It also attacks exotic plants such as fenugreek.
Black bean louse (Aphis fabae)
- Size: 1.7 - 2.7 mm
- Colour: matte black or dark green
- unable to fly
- Damage: Carriers of viruses and fungi (black fungi); Leaf roll symptoms and curling of the shoot tips
The bean louse is mainly found on beans, but also affects plants such as potatoes and beets. The glandular balsam is particularly popular, as a neophyte is widespread in Central Europe. The black bean louse does not overwinter with its food plants, but in shrubs like the common snowball (Viburnum opulus) or the Pfaffenhütchen (Euonymus europaeus).
Green peach aphid (Myzus persicae)
- up to 2 mm long
- Colour: black-brown
- airworthy (wings greenish)
- Damage: Leaf roll symptoms, signs of yellowing
The green peach aphid can only be found on peach trees.
Great rose aphid (Macrosiphum rosae)
- Size: 3 - 4 mm
- Colour: black (head), green - pink (body), rarely red specimens
- predominantly flightless
- Damage: Bends, discoloration; Carrier of sooty mildew
The great rose aphid specializes in roses. It is often difficult to recognize, because there are not only specimens in green, but also red in color. Only when generations with wings are created does a switch to other host plants take place. Then they usually colonize cardboard or valerian plants. In late summer the rose aphids migrate back to their preferred food source, the roses.
Note: White lice are often equated with aphids. white
However, lice do not belong to the family of aphids, but to the whiteflies.Multiplication
One reason aphids become a problem is because they can multiply quickly. If there is no male, aphids can reproduce without fertilization by another specimen. If there is not enough space on a plant, they often produce offspring that absolutely need fertilization. These offspring usually colonize new host plants and their offspring can reproduce them again without males. In this way, females can produce numerous offspring within a few weeks, making up to forty generations possible.
There are less winged offspring in aphids. A trigger for winged offspring is when the habitat becomes too scarce and they have to colonize new areas or when enemies threaten them. When a group of aphids is attacked by an enemy such as a ladybug, they emit a special scent that causes the next generation to develop wings.
Combat
Aphids produce sweet honeydew, which ants covet. Therefore, lice populations are often cared for by these insects, which favor an increasing population. It is therefore often more sensible to remove the ant nests first and then to control the aphids in the next step. The easiest thing to do is to relocate the ant nests. To do this, the ant's nest is first found and then a large pot is placed over the place. After several days, the insects have moved their nest in the pot and you can dig the ant nest with a spade and move it to a place where it will not cause any damage.
Once the ants have disappeared, you can fight the aphids. There are various home remedies available to you that do not damage the plants and are also harmless to other insects, as they are often deterrents.
Fern tea
- Chop 100 g of bracken or worm fern
- Bring 500 ml of water to the boil
- Pour hot water over the cabbage
- Let it steep for 24 hours
- simmer again for 30 minutes the next day
- Dilute tea with 500 ml of cold water
- Treat affected plants repeatedly every 2 days
Soap suds
- 50 g curd soap or soft soap
- 1 liter of hot (not boiling) water
- Rub the soap and dissolve it in the water
- Spray plants with it every 2 - 3 days
Note: The advantage of soft soap suds is that it not only drives away the aphids, but also clears stomata that are stuck together with honeydew, which are important for plant breathing.
Prevent aphids
One possibility is to actively remove the aphids, but it is much better if you do Preventing aphids, for example by establishing natural enemies or plants that they do not like underplant.
Natural enemies
- Ladybugs (larvae and beetles)
- Lacewing (larvae and flies)
- Ichneumon wasp larvae
- Predatory bugs
- Ground beetle
Plant herbs
Mediterranean herbs can also prevent aphids and their protectors, the ants. The intense smell of the herbs drives away the insects. Popular repellants for underplanting are:
- lavender
- thyme
- Savory
- peppermint
Strengthen plants
Plant strengtheners also help to make life difficult for aphids. Above all, this includes strengthening the plant epidermis. You can achieve this on the one hand by using nitrogen fertilization sparingly. You can also strengthen the plants with liquid manure. Nettle manure and manure with field horsetail are particularly helpful against aphids.
You prepare a liquid manure as follows:
- fresh herb in the amount of 2/3 of the chosen container
- Coarsely chop the cabbage
- Pour rainwater or tap water over it until the container is full
The liquid manure has to stand for several weeks until most of the herb has decomposed. Dilute the liquid manure in a ratio of 1:10 and use it to water the plants. If the plants already have aphids, you can also apply the liquid manure to the affected areas as a spray. The liquid manure is more of a long-term means. If you need a remedy that is available at short notice, you can also make nettles as a broth. To do this, pour boiling water over 200 g of fresh and crushed herb and let it stand for 72 hours. Then spray the plants with it.
