The appearance of black caterpillars on pine trees is considered quite a big problem. It is accompanied by massive yellowing and drying of branches, gnawing of bark, and deformation of shoots. Trees affected by such pests lose their decorative properties, lag behind in development and die after 3-4 years. Therefore, coniferous plantings require timely prevention. When parasites are identified, there is a need for intensive treatment.
What kind is this
Coniferous trees that suffer from pest attacks are more susceptible to various diseases.Black caterpillars often infect pine trees, entwining their needles with cobwebs. This helps them stay on the tree. Subsequently, a mining moth emerges from them.
Caterpillars that gnaw on needles, as they develop, turn into the following insects:
- Red sawflies are widespread throughout Eurasia. They are also partially distributed in North America. Adult individuals are characterized by a long shiny body of black or yellow-brown color - determined by sexual dimorphism. Females lay at least a hundred eggs during the season. They are able to withstand frosts even down to -40 degrees. Between late August and early September, adults emerge from cocoons. The main food for pests is needles. They can also absorb the juices of young branches.
- Pine cocoon moths are common in Europe and Siberia. These insects are considered quite dangerous. Adult butterflies have gray-brown wings with 3 transverse stripes. The caterpillars appear in mid-summer. At the same time, their body is covered with a large number of villi and reaches a length of 80 millimeters. At different phases of the life cycle, the color of insects differs. These pests feed only on pine studs. With the onset of cold weather, the parasites crawl into the moss located near the trunk for the winter. In a short period of time, parasites can destroy a hectare of pine trees.
- Pine moths are butterflies that have black or red wings. They lay eggs mainly in old pine needles. The caterpillars have a green body and reach a length of 3 centimeters. They are characterized by 5 white longitudinal stripes. Such insects appear in June. Moreover, their pupation occurs in November. Insects consume needles and young buds.A distinctive feature of the parasites is the sliding of cocoons into fallen leaves.
- Pine cutworms are common in the northern hemisphere. The danger of pests lies in their widespread distribution and ability to transmit other parasites. Adult butterflies can be identified by the spotted fringe on their wings and gray-yellow belly. The color of insects can be different - brown, gray-brown, reddish. The appearance of caterpillars is observed 2 weeks after egg laying. They feed on pine needles, young shoots and buds.
- The cone moth is widespread in Eurasia. These parasites lead a hidden lifestyle. Adults are characterized by a light gray tint to the wings. At the same time, transverse stripes and white dots are visible on the top pair. The caterpillars have a brownish-brown body. They feed on seeds from cones and apical shoots. Quite often, larvae are found in fungal-affected areas of trees where resin accumulates.
Why is it dangerous for a tree?
Black caterpillars are very dangerous for plants. Young pine sawfly larvae eat the sides of the needles, so you need to fight them as early as possible. Untouched fragments of needles begin to dry, turn yellow and curl. More mature individuals absorb the needles completely. A large number of larvae and a lack of food leads to gnawing of the bark, which will soon provoke massive drying of the branches in the blood.
Young coniferous trees can dry out within 3-5 years. Parasites provoke physical weakening of the tree. At the same time, the decorative characteristics of the affected pine and the overall composition are sharply reduced. Repeated infection by larvae in one season can cause the death of plantings.
How to deal with caterpillars
If the rules of care are followed, conifers rarely suffer from pest attacks. Favorable conditions for them are created by incorrect soil composition and acidity. Problems may also be caused by non-compliance with humidity parameters and lack of prevention.
A significant number of parasites are observed in areas where soil hygiene is poor and seedlings suffer from fungi and bacteria. To cope with pests, you need to start fighting them at the first symptoms. When the number of parasites is small, mechanical and biological methods are sufficient. During mass attacks, the need for strong chemical agents arises.
Manual cleaning
This method is suitable for eliminating small numbers of pine sawflies that attack young crops. In this case, it is necessary to remove eggs, larvae and adults from the branches. It is also recommended to get rid of spoiled sprouts and buds. They must be collected together with parasites in a separate container and burned outside the site. It is recommended to carry out the manipulation with gloves and glasses.
In addition, it is necessary to dig up the tree trunk circle. This helps to get rid of pupated individuals, which will subsequently bring new offspring. Some gardeners remove caterpillars with a powerful stream of water. After such procedures, it is important to pay attention to cleaning the area around the trunk.
When collecting caterpillars by hand, do not touch your face or other exposed areas of the body with gloves.This may cause allergic reactions.
It is recommended to place trapping belts on tall plants. They help block parasites that get close. Most often, an adhesive mass is used for this purpose, which consists of tar or resin. It is smeared on a cloth belt that is wrapped around the trunk.
Instead of an adhesive substance, you can treat the material with an insecticide. It is important to consider that such a trap helps get rid of caterpillars only at the stage of approaching pupation. Thanks to this they will slide to the ground.
Biological agents
This method involves the use of special products that are made based on natural ingredients. They are best used in spring – at the stage of flowering and pollination.
Pine can be treated with the following means:
- “Bitoxibacillin” is a bacterial insecticide, the active component of which is considered to be an exotoxin. It also contains bacterial spores. They cope successfully with caterpillars. Pests begin to die after 3 days, but the process lasts 2 weeks. After a week you need to re-treat.
- “Lepidocide” - the composition has an effect due to the presence of microbial spores. When caterpillars enter the body, bacteria synthesize crystals that lead to the death of the parasites.
- “Lepidobactocide” is a substance used to protect coniferous plantings on the site.
- "Biostop" - includes a complex of avermemectins. When caterpillars enter the body, bacteria synthesize toxic substances that provoke the destruction of the parasites’ digestive system.
Chemical methods
Chemical agents are considered the most effective.At the initial stages of infection, one treatment is sufficient, but in complex cases, 2-3 sprayings will be required. The most effective means from this group include:
- "Actellik" - produces an intestinal-contact effect on parasites. The product is sold in ampoules or canisters. After treatment, the nervous system of the parasites is damaged and they die.
- "Confidor" - the product contains imidacorid. Thanks to this, it helps to successfully fight pests.
- “Monsoon” - the composition perfectly protects against attacks of parasites and is not afraid of temperature fluctuations.
- "Arrivo" - the drug contains cypermethrin, which provokes damage to pests through poisoning.
- “Senpai” – causes damage to pests by contact.
Experienced summer residents choose insecticides with different effects, since parasites get used to one poison. It is recommended to spray plantings in dry and windless weather. In this case, you must adhere to the rules for working with toxic agents.
How to avoid it in the future
When using insecticides, you should focus on weather conditions. Sawflies breed in warm, dry weather. Therefore, at such times it is worth being vigilant. The rainy period leads to the death of caterpillars.
When creating a landscape composition, it is worth planting pine trees near deciduous trees. Thanks to this, the conifer suffers less from sawflies. The alternation of pine and hardwood trees makes it difficult for female parasites to find food.
It is also useful to attract birds that feed on caterpillars to your site.To do this, you can place birdhouses on the trunks or make nest boxes. It is also beneficial to plant more flowers in the garden.
Black caterpillars negatively affect the condition of coniferous trees. When pines are attacked, they can even cause their death. To cope with parasites, it is worth using biological products or chemicals. In simple cases, pests can be collected manually.
