Conifers, like all others, are susceptible to pests. You can deal with them by knowing what they look like and how they damage trees and shrubs.
Let’s consider the most common and dangerous pests of conifers.
Bark
Bark beetles can be called the most dangerous forest pests. Most parasites live and develop under the bark of coniferous trees, sometimes in the thickness of the bark or in the wood, drilling passages in them. Bark beetles are small, body length is from 0.8 to 12 mm, the color of pests, depending on the species, brown or black. At the end of the body is a flattened bevel, which is bordered by teeth.
By drilling the so-called uterine passage under the bark, females lay eggs. Hatched larvae, in turn, gnaw in different directions from him already their own, larval passages. At the end of the course, they make a camera – a “cradle”, in which they turn into a doll. Young beetles, hatched from pupae, gnaw through the flight holes, through which they come out.
Weakened, diseased, withering trees are mainly attacked. After infestation with pests, they die.
Spider mite
Spider mite is one of the most ubiquitous pests. It affects almost all plant species except aquatic. Not a specialist can spot ticks on larch, Christmas trees and junipers on the web. An experienced specialist will determine the presence of spider mites by the color of the leaf, as if it were watered with milk. Ticks are active in spring and summer, during which they can appear several times.
The size of individuals directly depends on their fatness, the length of females – 0.4-0.6 mm, males – 0.3-0.45 mm. Fleshy animals are characterized by an ellipsoidal shape, the upper part of the body is convex, the lower is flat. Mite larvae are transparent, light green to green-brown in color, there are 2 distinct, large dark spots on the sides. The color of wintering from late summer to spring females from orange to bright red. All adult ticks have 8 legs.
Nutrition of spider mites – this is the content of plant cells. The presence of the pest is evidenced by a thin web and the presence of small white dots on the needles. In case of severe damage, it is completely white, the whole plant is covered with cobwebs, the needles show a mobile mass consisting of the bodies of parasites.
The main prerequisite for the appearance of mites – low humidity, so a good prevention of the pest is regular spraying of the outer part of the plants.
Shields and false shields
You can meet thyme on juniper and Tuyahov, she began to appear on the yew. All shields have protective shields, they look like plaques on wood. In adult females, the shield is rounded, about 2 mm in diameter, in males it is smaller, oblong. The color of pests is reddish-brown or dark brown. The most dangerous females, because the larvae, leaving the eggs in a few hours settle on the entire surface of the plant and immediately begin to suck out all the juices, the needles are completely covered with shields. But the greatest damage is not caused by these parasites, and false shield bugs. Spruce pseudoshield is characterized by large size, it can reproduce quickly and en masse, causing serious damage to plants.
False shields differ from the shields in that the shield covering them from above does not grow together with the insect inside.
If you tear off the shield, the parasite will remain on the plant. Pests also differ in shields: in shields it is flat, in false shields it has the shape of a pea. Adults and larvae of both parasites function throughout the year, sucking all plant sap from plants.
The presence of thyroid glands can be recognized by the presence of brown or light rounded scales on the needles, which are difficult to separate from the plant. These are already adults. At strong defeat needles and trunks of trees and bushes are covered with a plaque which is formed because of big accumulation of parasites. The development and growth of damaged plants is delayed, the needles turn yellow and fall off.
At defeat of a false thyroid gland the needles lose shine, become brown and are covered with sticky allocations on which wasps gather. The parasite sucks the cell sap from the branches and needles. Red-brown or yellow spots appear on the damaged areas, leading to the death of parts of the tree.
Hermes
Hermes – a special group of pests that affect pine and spruce. Parasites form on the branches of trees, like a cone – galls.
There are several types of these pests. In late June, active early, which forms small oval galls at the ends of branches. Yellow hermes is activated in August, it develops large green galls. The late species of pests forms large globular galls in late August-September. Hermes females feed on tree sap and lay eggs on them. Emerging larvae damage the kidneys by deforming them. Then in these places the Gauls develop.
Sawyer
Spruce trees are attacked by spruce:
- Canadian;
Serbian;
European.
As a rule, spruces do not suffer much from these parasites, next year their needles are restored. Sawmills cause more damage to pines, sometimes you can find whole nests of insects on the branches. Weymouth pine, cedar, mountain and common are most often attacked. The abdomen of the insect is connected to the chest motionless, without the help of a stalk. The ova of females looks like a saw with which they cut plant tissue and lay eggs inside. Externally, the larvae of the sawfly look like caterpillars.
They eat young shoots of conifers from May to the end of June, the branches then look scorched and die. It is easy to fight these pests. The main task is to see the caterpillars in time and take measures to destroy them.
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