How to fight against leafhoppers in the garden ?

Leafhoppers are not welcome in the garden. There are different species, each infesting specific host plants. Few crops are spared, and the ornamental garden does not escape their direct or indirect damage either. Only softwoods are not affected by these undesirables. It is important to react quickly so as not to see the infested plants die. Admittedly, the task is delicate. Let’s see how to spot these sucking biting insectsand what are the best solutions to eradicate them but also to prevent their appearance.

Detect the presence of leafhoppers before it’s too late

We can suspect the beginning of an attack by frothy leafhopper larvae (Philaenus spumarus), very common in our gardens, foamy clusters present on certain plants. spring foam is the common name for this exudate excreted by adult females to protect their eggs. We also talk about frogspit… An infestation is also to be feared when we observe clumps of waxy-looking white fibers that other species of leafhoppers secrete. Small yellow dots on the leaves are also a telltale sign of their presence.

It is better not to let these pests settle in large numbers because by feeding on the sap of the plants that the leafhopper larvae colonize, the damage can be devastating. These are of two orders.

  • The direct damage: yellowing, drying out, necrosis, twig wounds, slow growth, lack of flowering, etc.,
  • The indirect damage: sooty mold due to honeydew, diseases that are transmitted to other plants…

The gardener must therefore keep a sharp eye on his plants in order to quickly detect this slimy moss or any other symptom that raises fears of the presence of leafhoppers.

Treat plants colonized by leafhoppers

Do not hesitate to use drastic measures as soon as an attack of leafhoppers is noticed. The longer we delay in reacting, the more we take the risk of seeing our plantations seriously wither. To begin with, we favor the installation in the garden of insectivorous birdsof the ladybugs by buying larvae in garden centres, lizards, all of which are major predators of leafhoppers. In parallel, one can resort to one of the following curative solutions:

  • The slurry (nettle, rhubarb, neem oil).
  • black soap mixed with water.
  • calcined kaolinite claywhose action is proven only against the vine leafhopper, vector of a fatal disease for these plants and particularly contagious, namely flavescence dorée.
  • The use of a predator specific, the hymenoptera Neodrinus typhlocybae which kills white leafhopper larvae exclusively, but watch out for the other side of the coin because it causes havoc itself. Only professionals know how to fully control the use of this predatory parasite.
  • Leafhopper traps such as a net with a very fine weft, or even a chromatic trap, that is to say a yellow plate coated with glue which attracts the adult leafhoppers and does not let them go.
  • A pyrethrum-based treatment which is used to eliminate many undesirables in the garden.
  • A powerful treatment product with a prolonged systemic effect chlorantraniliprole, thiacloprid, thiamethoxam, deltamethrin, etc.

Please note that this last category of processing may have environmental impact. For example, deltamethrin is used episodically and imperatively outside the flowering period. You should never abuse these products and prefer natural solutions. In any case, one must always ensure before use that the product in question is not covered by a ban because over the years, the list grows longer.

Monitor your plants for a reasoned fight against leafhoppers in the garden

The advantage of first resorting to a trap lies in the fact that one can easily count the leafhoppers caught. The goal is to strive for a rational use of insecticidesresorting to this practice testifies to the desire not to harm the environment.

A chemical insecticide presenting environmental risks, it should not be used if the weekly number of leafhoppers trapped is around twenty, and this, for two or three consecutive weeks. We can then be satisfied with applying a natural product in order to avoid a proliferation of pests, because it is a softer solution than a chemical potion. But this requires a diligent monitoring of all the plants in the garden, and you have to be very responsive in the event of an outbreak of insects.

The means of preventive control against leafhoppers in the garden

Rather than having to act when the damage is done and being forced to use tough methods by abusing products that are dangerous for the environment, it is better to take the lead. Different means allow protect your plantations against these peststo know :

  • Select your plants carefully at the time of purchase. They must be healthy. It is recommended to opt only for certified seedlings.
  • The chemical insecticide to preventive action: a treatment is to be applied during the first half of April, then another eight weeks later. It is important that the statement ” Authorized use in gardens » does appear on the label. This does not dispense with strictly respecting the rules of use recommended by the supplier. Note that this type of insecticide acts on all the organs of a plant. We speak of a systemic effect.
  • Use onlywith parsimony a fertilizer rich in nitrogen when fertilizing plants more particularly targeted by leafhopper attacks.
  • Opt for judicious associations in the garden. Some plants act as insecticides or at least repellents (all things considered). This is the case of Petunia, Chrysanthemum from which pyrethrum is extracted, Botanical Geranium, Lavender…

Given the damage caused by leafhoppers, all plants at risk should receive preventive care.

The difficulty, whether preventive or curative, lies in the fact that certain solutions only work on very specific species of leafhoppers as we have seen previously and certain means of control pose, in fine, problems. This is for example the case of Neodrinus typhlocybae only effectively attacking the white leafhopper and otherwise creating havoc.

It is therefore essential to identify with certainty the pest species seen in the garden in order to find a targeted solution and to ensure that the chosen treatment is risk-free. Of course, with several sprays of black soap, we obtain satisfactory results regardless of the leafhoppers, provided of course that the colonization of plants by these biting sucking insects is moderate.

Leafhoppers can set their sights on more than four hundred plant species. This shows the difficulty to which the gardener is exposed, especially since it is not so easy to fight against this plant pest since in addition to having to identify the species present, it is necessary to resort to a treatment specific without danger for the planet and beneficial insects… In the event of an invasion of leafhoppers, the amateur gardener has every interest in hire a professional gardener who will find the best solution.

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