Scaffolds and False Shields
You can meet the scabbard on the juniper and thuja, she began to appear on the yew. All guards have protective shields; they look like plaques on a tree. In an adult female, the shield is rounded, with a diameter of about 2 mm; in a male, it is smaller, oblong. The color of the pests is reddish-brown or dark brown. Females are most dangerous because larvae, leaving the eggs within a few hours, spread over the entire surface of the plant and immediately begin to suck out all the juices from it, the needles are completely covered with shields. But it’s not these parasites that cause more harm, but the false shields. The spruce false shield is characterized by a large size, it is able to reproduce quickly and massively, causing serious harm to plants.
False shields differ from shields in that the shield covering them from above does not grow together with the insect inside.
If the shield is pushed open, the parasite will remain on the plant. The shields themselves also differ in pests: in scutes, it is flat, in false scutes, it has the shape of a pea. Adult individuals and larvae of both parasites function all year round, sucking out all cellular sap from plants. The presence of scabies can be recognized by the presence of the needles of brown or light rounded scales, which are difficult to separate from the plant. These are already adults. With severe damage to the needles and the trunks of trees and shrubs are covered with a bloom, which is formed due to a large accumulation of parasites. The development and growth of damaged plants are delayed, the needles turn yellow and fall.
In case of a lesion with a pseudo-scutellum, the needles lose their luster, turn brown and become covered with sticky secretions, on which wasps flock. The parasite sucks the cellular juice from branches and needles. Red-brown or yellow spots appear on the damaged areas, leading to the death of parts of the tree.
It is not easy to deal with shields and false shields, as they are protected from external influences by shields. At the initial stage of infection, you can try to use a soap-alcohol or soap-kerosene solution. In case of severe damage, insecticides (“ Aktara ”, “ Confidor ”) or insectoacaricides, for example, “ Aktellik ” are used. It will take 2-3 treatments, it is better to do this with drugs belonging to different chemical groups. A week should pass between treatments.
Hermes is a special group of pests that infect pine and spruce. Parasites form on the branches of trees similar to a gall cone. There are several types of these pests. At the end of June, the early one is active, forming small oval galls at the ends of the branches. Yellow Hermes is activated in August, it develops large green galls. The late species of pests form large spherical galls at the end of August-September. Hermes females feed on the sap of trees and lay eggs on them. Emerging larvae harm the kidneys by deforming them. Then on these places galls develop.
Outside, these parasites are covered with a downy outgrowth, which makes it difficult to combat them, for which systemic insecticides are used, for example, “ Commander ”.
Spruces attacked sawflies:
- Canada ;
- Serbian ;
- occasionally – prickly.
As a rule, spruce trees do not suffer much from these parasites; next year their needles are restored. Sawmills inflict more harm on pine trees, sometimes you can find whole nests of insects on the branches. Veymutov pine, cedar, mountain and ordinary, is more often attacked. The abdomen of the insect is connected to the chest motionless, without the help of the stalk. The ovipositor of females looks like a nail file, with which they incise plant tissue and lay inside the egg. Outwardly, sawfly larvae look like caterpillars. It is they who eat young shoots of conifers from May to the end of June, the branches after which look burnt and die. Fighting these pests is easy. The main task is to see the caterpillars in time and take measures to destroy them. “BI-58”, “Actellik”, “ Decis ” and “Fury” will help in this.