The appearance of a white coating on cedar is a sign of infection with a dangerous pest - Hermes. This sucking insect belongs to the order Homoptera and resembles an aphid in appearance. It may be black, green or brown in color. Parasites feed on tree sap. They are mainly found on needles and young shoots. To cope with insects, you can use a variety of means.
How to identify Hermes
The infection of cedar pines by Hermes is accompanied by the formation of a white coating on the needles, branches and trunks of crops.With a large number of parasites, all above-ground plant fragments are affected. The old fluff covers the shoots with a continuous veil and is difficult to remove from the crop.
At the initial stage, pests only attack the shoots of the current year. Fresh fluff is soft and can be easily removed from the needles with your fingers. When the plaque is rubbed between the fingers, yellow-brown stains remain on them, which are difficult to wash off with water. This sticky liquid appears after crushing the larvae of parasites, which are poorly visible to the naked eye and are securely hidden in a white shell.
In addition, the needles of the affected tree slow down in development and are often deformed. At the same time, the affected branches lighten and become shorter. In addition, there is a complete suppression of cultural development. In addition, the decorative properties of the tree are greatly deteriorated. It gradually dries out.
The weakest trees suffer first. This applies to crops that grow in low places, in waterlogged soil. Moreover, plants that grow in well-drained soil are able to withstand attacks from parasites for several years.
Causes
The appearance of Hermes on cedar pine is considered a very common occurrence. The main cause of plant damage is considered to be a violation of the rules of agricultural technology and incorrect soil composition.
The risk group includes cedars growing in lowlands. In this case, favorable conditions are created for the proliferation of parasites. Humidity in the soil also affects the development of pathologies.When growing a tree in waterlogged soil, it will quickly lose its decorative value.
Harm of white plaque
Cedar, which is attacked by Hermes, begins to lag in growth. This is most common for young trees. In some cases, tree trunks become deformed and bend towards the ground. The more severe the wilt, the more dangerous the damage to the tree is considered. However, the key danger lies not only in the deterioration of appearance.
Cedar affected by Hermes is more susceptible to infectious pathologies - in particular, rust. This disease is also called seryanka or tar cancer. The pathology is associated with the spread of rust fungi through spores. This disease can also be transmitted to other trees.
In addition, the crop may suffer from bark beetle attacks. In this case, there is a risk of damage not only to bushes and trees, but also to wooden buildings.
Treatment options
To manage pests, it is important to take an integrated approach. In this case, it is necessary to completely destroy insects. If at least a few females remain on the tree, they may develop resistance to the drugs. In this case, there is a risk of the problem repeating, but on a larger scale.
To combat Hermes, you should use several methods at once. Depending on the degree of damage and the severity of the problem, each of the remedies shows different levels of effectiveness. The first measures should be taken in the spring – around mid-April. After this, you need to do a control approach in May. This will help destroy all generations of aphids. It is recommended to repeat the procedure in June and July.
Traditional methods
In simple cases, using traditional methods is sufficient. They are usually used if there is a thin veil of fluff on local areas of the tree.In such a situation, it is worth treating the cedar with soapy water. You can additionally add garlic, pepper, onion, and tobacco infusion to your home remedies.
Use of drugs
To more effectively kill parasites, it is worth using systemic insecticides. The most effective remedies in this category include:
- “Fitoverm” - to prepare the working solution, it is recommended to use 4 milliliters of the substance per 1 liter of water. Plantings should be processed at intervals of 10-15 days.
- “Inta-Vir” - in this case you need to take 1 tablet for 10 liters of water. In total, it is recommended to treat the tree 2-3 times. Spraying is carried out at intervals of 15-20 days.
- “Confidor” – it is recommended to take 1 gram of the drug for 5-10 liters of water.
- "Actellik" - this product is considered more toxic, therefore it should be used only as a last resort. In this case, take 2 milliliters of the substance per 2 liters of water.
- “Aktara” - to prepare the working solution, it is recommended to use 2 grams of the product per 10 liters of water. In total, 2-4 wood treatments are required. They are carried out at intervals of 15-20 days.
Injections
When using the injection method, the number of treatments can be reduced. This method is considered the most labor-intensive, but it is completely safe for people and animals, since the chemicals do not spread over the surface of the crops.
To use this method, a special drug must be injected under pressure into the vascular layer. The active agent immediately enters the structure of the tree, including the juices that Hermes absorbs. As a result, the death of adults occurs.
The solution must be administered under strong pressure. This will help distribute it throughout the cambium as evenly as possible. For injections, it is worth using ready-made systems, which include complete sets of tools and mixtures.
Fog treatment
To get rid of white plaque on tree shoots, you need to treat with cold or hot fog. For this purpose it is worth using motorized sprayers. Steam installations are also an excellent option.
Cold fog has a temperature that matches the environmental parameters. The disinfection cloud is characterized by its uniform distribution over the area. It stays in the air for up to 4 hours and is completely safe for pets and plants. Cold fog suppresses most insects. However, it is important to consider that eggs may remain in hard-to-reach places.
When using the hot fog method, the solution is released into the air with gas. Temperature changes cause hot drops to break up into small particles. They remain in the air for 10 hours. During this time, chemicals enter even small cracks and provoke the death of larvae that were not destroyed by the cold fog.
Generators for using such methods are sold in specialized stores. However, it is better to contact professional disinfectants. Without the necessary skills, there is a risk of incorrectly calculating the dosage and harming your health.
How to avoid infection
To cope with pests on needles and branches, it is important to do the following:
- When choosing seedlings, carefully inspect them.
- Plant the crop in well-drained soil with normal water balance. It is important to water the crop in a timely manner. To remove excess moisture, it is necessary to use a rocky or sandy layer.
- Use fertile fertilizers. Special means, fallen pine needles, and peat are suitable for this. Before planting, the soil must undergo simple cultivation. It needs to be calcined and a fungicide applied. To maintain optimal acidity and prevent root rot, it is worth using dolomite flour and chalk.
- Treat the trunk and crown with special products designed for conifers.
The appearance of a white coating on cedar indicates attacks by Hermes. This pest can significantly deteriorate the appearance of the tree and slow down its development. To cope with parasites, you can use folk remedies or professional preparations.
