Bean pests

The bean belongs to the legume family and is a widespread crop, especially in southern Italy and on the islands. In these areas, it represents one of the main crops, along with wheat, which continues in rotation.

Legumes are a very important family because they are nitrogen fixers, that is to say they allow the supply of nitrogen to the soil. Therefore, they are known as soil improvers, and in rotations they follow draining crops such as cereals, which in turn remove nitrogen from the soil and deplete it.

To ensure the good health of the bean plant and therefore a good harvest, it must be possible to preserve it from possible problems, even organic farming plans to intervene with methods of defense against possible pests.

Prevention is important in the control of the main insects that attack beans, which consists of using good agricultural practices. Knowing in detail the main insects that attack beans is particularly useful to be able to intervene in time in the event that one of these unpleasant pests attacks the beans in our garden.

Contents [Ocultar]

  • Black aphid and greenish legume aphid

  • cochineal

  • Torch

  • cedomy

  • Stem punch (Lixus algirus)

  • Bean tuna (Bruchus rufimanus)

Black aphid and greenish legume aphid

Two species of aphids can attack broad beans: the black aphid (Aphis fabae) and the green legume aphid (Acyrthosiphon pisum). These small insects carry out their life cycle by colonizing different plants, both cultivated and spontaneous, such as viburnum and sooty, the most obvious damage to crops occurs in broad beans, beans and alfalfa.

The individuals of aphids live in the shoots, in very numerous colonies causing floats and chains very obvious. Minor shoot infestations cause a topping-like effect, promoting pod production.

In addition to this damage, defined as direct, aphids also cause indirect damage, i.e. transmission of the virus (e.g. wax bean mosaic, BMYV, or Sharka M strain, plumpox virus PPV). The mode of transmission is mainly related to the aphid’s habit of making several tastes on the plant to determine the quality of the lymph: in this way, the viruses reach the salivary glands or graft onto the surface of the stylet, contaminating the aphid and its subsequent food substrates, causing the virus to spread.

Another problem caused by aphid infestations, and which comes under indirect damage, is that due to the production of molasses a waste of a sweet nature, which causes burns in dirty fabrics and proves to be an excellent substrate for the growth of saprophytic fungi ( soot ) and mussels.

To protect the bean from aphids, it is necessary to carry out operations aimed at containing host plants from weeds, cleaning the edges or using false seeding. It may also be advisable to anticipate the time of planting, using less susceptible bean varieties. In the organic garden, you can use vegetable macerates that repel these insects, such as garlic decoction or pepper macerate.

In the event of particularly severe attacks, biological control can be envisaged by introducing predators of aphids, such as ladybirds, into the environment.

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