Are your beans or ornamental plants infested with the black bean aphid? We explain how to prevent black lice and fight them successfully.
Aphids can be found in almost every garden, especially the black bean aphid. But the bean aphid can not only infest beans. We'll show you how to fight black lice naturally and prevent re-infestation.
Detect black bean aphid
The black bean aphid (Aphis fabae) is one of the most common aphid species found in gardens. The black bean aphid does not only affect beans (Phaseoleae) for a long time. In addition to the particularly susceptible beans such as field beans (Vicia faba) and other legumes (Leguminosae) such as peas (Pisum sativum), beetroot ( Beta vulgaris subsp. vulgaris), chard (Beta vulgaris subsp. vulgaris ), Spinach (Spinacia oleracea), Asparagus (Asparagus), Dahlias (Dahlia ) or Clematis infested with black aphids.
As the name suggests, the black bean aphid is black in color. The best way to identify an infestation with aphids, such as the black bean aphid, is to look at the shoot tips or flower buds of your plants. Here the black lice particularly like to suck on the sweet phloem sap of the plants. Symptoms that indicate an aphid infestation are deformed young leaves and shoots, leaves covered with honeydew and an increased occurrence of ants. Ants and aphids often appear together. The ants are after the sticky honeydew that the lice excrete when sucking on the plant. They even protect the lice from predators. Honeydew also accumulates on leaves and can be colonized by sooty mold fungi (Capnodiales), which inhibits photosynthesis in plants.
Lifestyle and characteristics of the black bean aphid
The black bean aphid changes host plants in autumn and lays their eggs on the so-calledwinter hosts. The euonymus (Euonymus europaeus) or snowball (Viburnum opulus) are the winter hosts of the black bean aphid. Winged female lice hatch here from March and spread to summer hosts such as beans and spinach from April. Once a host plant has been found, a single female can give birth to multiple offspring in a day without relying on male fertilization. Especially in dry and warm weather, mass propagation can occur quickly. From June or when there is a threat of danger or overpopulation on a plant, winged aphids hatch again, which can travel longer distances and thus infest plants that are further away. In autumn, the aphids seek refuge with the winter hosts and lay eggs there again, which survive the winter.
Control of black bean aphid
Individual aphids are not a problem. However, if there are too few beneficial insects and warm, dry weather, mass proliferation occurs, plants can be damaged by aphids. To control aphids, it is not absolutely necessary that you can determine exactly which species of aphid you are dealing with. We'll show you how to fight black aphids successfully and naturally.
Control black aphids biologically
There are a number of ways to combat aphids. We recommend that you refrain from using synthetic agents, as they carry a higher risk of harming beneficial organisms or the user. Instead, there are very effective and environmentally friendly biological alternatives. Means based on neem are particularly effective against black aphids. Neem oil comes from the seeds of the Indian neem tree and contains an active ingredient that enables the natural control of aphids.
Remedies based on rapeseed oil are also available to combat aphids. However, these have no systemic effect, so they cannot be absorbed by the plant. Some remedies contain pyrethrins, which can be obtained from plants, but can still damage many different beneficial organisms.
Home remedies for black bean aphid
Especially a light infestation by the black bean aphid can be combated with home remedies. One of the most effective home remedies is soapy water made from 150 grams of soft soap dissolved in five liters of water. The soapy water canthen applied to the affected plant several times a day. Nettle broth can also be used against aphids. To do this, add 500 grams of fresh nettles to five liters of boiling water and let this brew cool down. You can use a spray bottle to spray the strained brew onto the affected plants twice a day. You can find out more helpful home remedies in our special article on home remedies for aphids.
Beneficial insects against black aphids
Beneficial insects help in the garden, especially as natural opponents, to prevent mass propagation. The targeted use of beneficial insects in the event of an infestation by aphids is also possible. Beneficial insects such as ladybird larvae or parasitic wasp eggs can be bought in special online shops. This targeted use is particularly effective in closed rooms, for example in the greenhouse or in the conservatory. We have summarized other exciting tips for beneficial insects against aphids in our special article.
Prevention of black aphids
The arrival of aphids is impossible to avoid. Sooner or later you as a garden owner will be confronted with the pests. However, it is wise not to plant winter hosts of aphids, such as the euonymus and snowball tree, in the garden. Owners of natural gardens have a clear advantage when it comes to aphids, because a particularly natural garden offers many beneficial insects a home. A balanced ratio of aphids and their predators can prevent mass proliferation of aphids. Some types of parasitic wasps and ladybirds can be used as beneficial insects against aphids. In order to prevent a heavy infestation, we recommend that you specifically promote beneficial insects in your garden. In summer, a pristine flower bed filled with native flowering plants and herbs is helpful in welcoming beneficial insects. Our Plantura beneficial insect magnet is a seed mixture that makes it easier for you to create such a flower meadow. In the cold season, places of retreat such as a bark accumulation or an insect hotel are ideal for helping beneficial insects through the winter.
A adapted fertilization of your plants can also reduce the likelihood of aphid infestation. We recommend that you ensure a good supply of potassium and refrain from fertilizing with a high nitrogen content. This ensures vigorous plants that are less likely to be attacked by aphidsbe infested. A primarily organic fertilizer with a high potassium content, for example, is our Plantura organic tomato fertilizer.
Avoiding too dense stands is also helpful in growing vigorous plants and reducing aphid jumping in spring.
Tip: Aphids often appear in spring and are then pushed out by beneficial insects over the course of the year. Therefore, it is perfectly fine to tolerate a light infestation in the spring or to fight it with home remedies and only react with sprays when the infestation is severe.
The queen of flowers, the rose, is particularly fond of aphids. In our special article on aphids on roses, we give you tips on how to get rid of the pests.