Birch sapwood belongs to the bark beetle family and is one of its largest representatives. The body of an adult is black, shiny, its length is 4.5-6.5 mm, the antennae and legs are brown. Bark beetles are characterized by weak sexual dimorphism. The male differs from the female by the presence of dense long hairs on the forehead.
Representatives of both sexes have a short longitudinal keel above the jaws; in males there is a small rounded depression between the eyes. The shield is evenly dotted with small dots. On the flat elytra, longitudinal furrows of coarse punctation are clearly visible, with small dots in the spaces between them. In the posterior part of the elytra, the edges are smooth without any relief. Well developed membranous wings.
The abdominal segments are slanted upward; in males, on the third abdominal segment there is a relatively large tubercle resembling a button. On the fourth segment, two closely spaced tubercles merged into a larger formation with a notch in the center. The abdominal segments of females are smooth without any thickening. The antennal flagellum consists of seven segments and is crowned with a three-membered flat club of oval shape.
Description
Adult sapwood reaches a length of 1.5 to 5.5 cm. They are characterized by a dark body color, which can be completely black or with a red or brown tint. Some species have transverse bands. A well-recognized feature of the genus is the massive pronotum, the width of which is almost equal to the width of the abdomen.
In temperate climates, the active summer of sapwood occurs in May–July. This is a time of active reproduction: after mating, the female lays eggs under the bark of a suitable tree. The larvae that appear soon gnaw at it, feeding and making tunnels.
Sapwood beetles wait out the winter as larvae, hiding from the cold in wood. In the spring, when fruit trees bloom in the gardens, the insect transforms into a pupa, and then into an imago.
Signs of infection
Characteristic signs of the appearance of a bark beetle in the house will be:
- entrance holes in wooden structural elements - those species that prefer deciduous trees leave clearly visible entrance holes on the bark;
- in the cross-section, the insect’s nest will be clearly visible, having the appearance of a complex pattern - its beginning can be seen at the entrance channel, then passes into the mating chamber, perpendicular to which numerous, often entangled, larval passages will be located;
- the surest sign is drilling flour on the surface of the wood and on the floor under the infected wooden element;
- sometimes resin funnels are clearly visible near the inlet.
Pests enter the wooden elements of a residential building from trees growing nearby, or are brought in with building materials. And it is better to provide protection from bark beetles even before construction. To do this, it is necessary to carefully inspect the lumber before purchasing it for the presence of small oval holes. Contaminated products, next to which there will be sawdust flour, should be immediately discarded.
After purchasing building materials, it is advisable to sand each log and post, and collect the bark and burn it outside the site. Plus, wooden elements must be impregnated with special preparations. Products such as “Antishashelin”, “Antizhuk”, “Empire 20”, “Akvateks”, “Wood Doctor”, “Senej”, etc. have proven themselves to be excellent preventative agents. Bark beetle treatment is carried out for all types of wood, regardless of the degree of their impregnation.
Kinds
Of the 120 species of sapwood existing in the world, four live in the territory of the former USSR and are significant for human activity.
Birch sapwood
This is an oligophage, that is, the insect harms only birch trees. Other types of trees are not interesting to him. The damage is caused by larvae developing in the bark and young beetles that use the birch as a source of additional food, often eating the succulent bark near the buds.
The adult of the sapwood is a beetle whose body length is from 4.5 to 6.5 cm. It is painted black, which tends to shine in the light. The upper surface of the elytra and part of the pronotum are brownish-red. The active years of birch sapwood occur in May.
The beetle rarely attacks young trees, preferring old and middle-aged ones. The choice of a female does not depend on the health of the birch tree and its location. Birch sapwood can also affect woody material: firewood, boards, solid wood. As a result of the pest's activity, birch trees become weak and may dry out completely; and the marketable characteristics of harvested wood are reduced.
Birch sapwood lives in the European part of the Russian Federation, in the Caucasus region, in Siberia to Transbaikalia; also common in Ukraine, Western Europe and Mongolia, where birch trees grow.
Elm sapwood
Small and large elm sapwood differ from each other in size. The length of the first is 3.5–4.5 cm, and the second – from 4.5 to 5.5 cm. What they have in common is that the larvae of these species prefer to live on ash (elm) trees. But they often parasitize other trees: hornbeam, oak, aspen. The beetle is dangerous primarily because it carries fungi that provoke the development of Dutch disease. Their habitat coincides with the distribution area of the birch sapwood.
Fruit sapwood
They cause harm to human households because their larvae and beetles gnaw on the bark of garden trees, especially often affecting cherries and plums. They are ubiquitous in Europe, Western Siberia and the northern Caucasus. On the European territory of Russia they live in the Non-Black Earth Region. These shiny beetles have a black head and pronotum, abdomen and elytra with a brown-red tint. In addition to garden trees, they can choose elm, hawthorn, rowan and other species.
Research methodology
Based on information obtained from the processing of literary data, an annotated list of bark beetles of the Bobruisk region was compiled, including 23 species.
The taxonomic structure of the family has been studied. To characterize the habitats, the descriptive nomenclature of K.B. Gorodkova (1984), which allows for zoogeographic analysis based on a unified terminological approach.
Photographs of bark beetle damage on various trees were taken, identified and described according to Stark.
Insects were collected from May to August. For this, three biotopes were selected: biotope No. 1 - mixed forest, biotope No. 2 - pine forest, biotope No. 3 - mixed forest - roadside.
Collection was carried out on damaged trees. At the same time, the bark was removed from the tree and examined for the presence of various Coleoptera. The found specimens were placed in a fixative (92% ethyl alcohol). The collected material was determined in laboratory conditions. Subsequently, fixation was carried out using entomological pins.
Garden pests
Sapwood larvae live in the bark of trees, making numerous tunnels in it. In the spring, when fruit crops bloom, pupation occurs.
The emerging beetles, in order to break out and continue their lineage, make almost perfect circular holes in the bark. It is easy to tell from them that the garden is suffering from sapwood.
Pathogenic microorganisms: bacteria and fungi easily penetrate into the plant through the holes, which leads to secondary diseases. Gnawing through the bast, one of the layers of bark, causes the branches to die off, followed by the death of the tree. The third aspect of harm from sapwood is gum formation in stone fruits, that is, the leakage of sticky liquid: brown, yellow or transparent. This is caused by beetles gnawing out areas in the forks of branches and around the buds. As a result, the buds and young shoots of the tree die.
Signs of tree infestation
Drying of needles on spruce and pine trees. Usually the tree begins to weaken, the needles become sparser and begin to turn yellow, acquiring a red or bright yellow color. First, individual branches dry out, then the whole tree.
Active shedding of needles. If the needles of a spruce or pine tree begin to actively fall off, then this is a sure sign of a tree disease or infection with a bark beetle.
You need to pay close attention to such trees.
The appearance of woodpeckers and other birds that feed on tree parasites. This is also a sure sign of infection of the trees on the site.
The appearance of sawdust and “drill” (brown) flour at the roots of the tree
The bark beetle eats through the passages and carries the wood outside. Such trees can no longer be saved; they must be removed as soon as possible.
Holes 3-5 mm in size appeared in the bark. Usually the bark beetle infests from a height of 6-8 meters and the holes are not visible from the ground! When holes begin to appear lower down, this is a sure sign that the tree will soon die.
Strong release of resin from pines and fir trees. This is a sign of the tree’s fight against pests and diseases, a protective reaction to external factors.
Tree bark falling off. This is the last stage of the tree's life, when sap flow has stopped and the bark beetle has eaten all the bast tissue. The tree is already dead, and the bark beetle is ready to emerge again. Such trees must be removed immediately, even if green needles are still present on them.
Struggle
The fight against sapwood is necessary to maintain the health of garden inhabitants and harvest a good harvest. If infection is allowed and chemicals are not used, the fruits will be small and tasteless, and after 4–5 years all the plants may die.
Agricultural technology
Order in the area is the main guarantee of healthy plants. Agrotechnical methods of combating sapwood include special measures:
- pruning dry and pest-damaged branches, which must be burned after the procedure;
- cleaning tree trunks and branches from mushrooms, moss or lichens, because they are a natural shelter for the beetle;
- timely application of organic and mineral fertilizers for general health purposes;
- whitewashing of trunks and bases of skeletal shoots.
All these actions will not take much time, but the benefits from them will be enormous.
Goldentail
It is a medium-sized butterfly with a wingspan of 30–40 mm. The body of the insect is white. A characteristic feature is the presence of a tuft of golden or brown hairs at the end of the abdomen. The wings are white with black dots. The color of the caterpillars is grayish-brown, and their entire body is covered with bristles. The length of the bristles sometimes reaches 7 cm. The bristles secrete a toxic substance, which, if it comes into contact with the skin, causes severe irritation. The pest is found in European Russia and Central Asia.
For the winter, the caterpillars settle in special nests attached to the branches of the crown. Nests can contain up to 2000 individuals. When the air temperature reaches 8 °C, the caterpillars leave the nests and begin to feed on buds and leaves. After 30–40 days, the caterpillars pupate. Female lacewings have average fertility; they lay eggs in clusters of 200–400 each. The embryonic period lasts 15–20 days. Caterpillars cause damage by skeletonizing leaves, covering them with cobwebs. Over the summer, one generation of pests appears.
The goldentail parasitizes all fruit trees, as well as many forest medicinal plants.
Plum sawfly
There are black and yellow plum sawflies. The insect develops when the plum blossoms and forms ovaries. For wintering, the pest in the larval phase goes into the ground to a depth of 20 cm. With the arrival of the spring season, pupation of the larvae occurs. The emergence of adults occurs during the flowering period.
You can see small flies with a yellow-brown color and transparent wings - these are yellow sawflies. There are their cousins - black sawflies: flies with brown veins. However, the larvae are more harmful because they mercilessly eat the buds.
Plum pests
At first, harmful insects focus on plum varieties that bloom in early spring. If it is at least +10 °C outside and gardens are blooming en masse, this is considered the optimal time for the plum sawfly to emerge and lay eggs.
The places where females lay eggs are easily identified by small protruding rusty spots. The number reaches 7 eggs per ovary. The hatching of larvae occurs at the end of flowering and signals the penetration of pests into the buds.
For your information. One individual is capable of destroying about 6 ovaries that fall off.
Insects love to live in plantings that differ:
- flowering;
- crown density;
- wind protection.
A prolonged stage of flowering and budding is a threat to the future plum harvest: the owners of the plot may miss 90% of the fruit.
Control methods and prevention
Measures to combat the plum sawfly include spraying plums a week before flowering with Kemifos or Fufanon. When flowering is completed, the procedure is repeated with the same chemicals.
For preventive purposes, you will need to dig up the soil in the tree trunk area. Before flowering, plum sawflies are shaken off the tree onto a rag and eliminated. In summer it is necessary to remove infected fruits.
Fruit rot
The disease manifests itself in the formation of brown spots of rot on ripening apples. They grow in size quite quickly and soon cover the maximum part of the fruit, greatly deteriorating its quality. The number of rotten apples on the tree, which simply fall to the ground, is growing rapidly. The pulp is usually completely inedible.
For fruit rot, the drug most often recommended is one that we have already mentioned many times in the current material - “Hom”, which must be diluted in a proportion of 40 g per bucket of clean water. The resulting solution is sprayed. There should be two of them - during the formation of young leaves and after flowering. The consumption of the finished solution for each adult and fruit-bearing tree is about 5-6 liters.
Shchitovka
Beginning gardeners often mistake false scale or scale insects for droplets of gum that have frozen, and for growths on the bark.
Shchitovka
Distinctive features of both types:
- inactivity;
- excellent camouflage.
Pests directly dig into young branches and leaves, growing into them and intensively sucking out the juices of the tree. Only young individuals, as well as males, move. Massive plum infection threatens:
- weakening of fragile plantings;
- drying out and falling of leaves;
- loss of fruits;
- death of trees.
Measures not taken in a timely manner make it difficult to fight scale insects. The insects reproduce at a rapid rate and produce honeydew, a favorite habitat for sooty fungus, which makes breathing difficult and inhibits growth.
The differences between scale insects and false scale insects lie in shape. The first parasite has a flattened scutellum. The false scale resembles a hemisphere, in addition, it is not absorbed into the bark, detaches mechanically and does not exude honeydew.
False shield
Control methods and prevention
If the scale insect is on a drain, the methods of control are chemicals coupled with folk remedies.
They fight false scale insects in the same way as when infecting plants with scale insects. Parasites are removed with a brush and the branches are treated with kerosene with the addition of laundry soap or a mixture based on alcohol and soap.
Covering large areas with insects is a reason to turn, along with folk remedies, to methods of chemical protection. Spraying is carried out several times with a break of a week.
Fruit striped moth
An inconspicuous gray-brown moth. The caterpillars are up to 1.5 cm in length, have a chestnut body and a black head. They overwinter in young branches, climbing under the bark. They are most often introduced in forks. In spring, they gnaw out the core of young shoots and eat off leaf buds. After the death of one shoot, they move to another. Two generations of the pest appear over the summer.
All branches damaged by the sawfly must be promptly cut and burned.
Treatment with insecticides is carried out before the buds open, after the end of flowering, while the cherry petals are falling off.
They use Actellik, DNOC, Chlorophos, Zolon.
Raspberry beetle
The adult is grayish-yellow in color, with a body length of no more than 4.5 mm. A characteristic feature of the larvae is brown transverse stripes on the back. In warm winters, beetles and larvae sink into the soil to a depth of 5–10 cm, in harsh winters - to 25 cm. They emerge to the surface in mid-May and feed mainly on the nectar of flowering weeds and fruit trees. With the appearance of the first buds and buds on the raspberry, the beetles fly to it. During the raspberry flowering period, they lay eggs one at a time between the stamens of the flowers. Females are not fertile; one female can lay only up to 40 eggs. The hatched larvae bite into the stalk and damage the berries. Subsequently, the berries wither and fall off. Pupation of larvae occurs in early August. Most of them develop into adults, the rest remain in the soil as larvae until the fall of next year.
Pear bug
Although this is a pear bug, it does no less harm to apple trees.
This is a small insect, with a flat and comb-like prominence in the middle and lobe-shaped outgrowths on the sides. The fore wings are leaf-shaped, expanded, transparent, with a coarse-mesh network of dark veins.
For the winter, adult bedbugs nest under fallen leaves. And in the spring, as soon as the trees fade, the females begin to lay elongated black eggs on the underside of the leaves.
After three to four weeks, larvae appear and suck the juices from the leaves. They feed like this for up to 25 days. And then they turn into bedbugs.
Light spots form on the leaves of apple trees and merge. And then the leaves turn yellow, turn brown, dry out and fall off. Later, the fruits become smaller and fall off.
How to deal with the pear bug
- Clean the bark of the tree, rake and destroy fallen leaves. Dig up tree trunk circles.
- Spray the trees with infusions of onions, yarrow, and solutions of laundry or green soap. Or use ready-made drugs from manufacturers strictly according to the instructions. Spraying should be carried out immediately after apple trees bloom.
Ticks
Plum trees can be affected by gall mites or red mites. Both types of these mites have similar body colors, as can be seen in the photograph. They are reddish-brown. Under the influence of gall mites, growths form on trees - this is a sign by which the presence of pests in the garden is determined. They can usually be seen at the base of branches. These are peculiar houses (galls) in which ticks spend the winter - here is a photo.
In the spring, when the street temperature stabilizes at 15 degrees, the gall mite leaves its wintering place and begins harmful activities. Most of all, ticks love to feed on young shoots of plums.
During a season, several generations of gall and red mites can change. Their number depends on local climatic conditions.
The larvae hatch from eggs before the plums begin to bloom and immediately begin to feed on young leaves. Under their influence, much fewer flowers and, accordingly, ovaries appear on plums. Worse, the resulting flowers and ovaries fall off.
Ticks begin laying eggs in mid-summer. They are clearly visible on the underside of the leaves.
Plum (reed) aphid
The pest overwinters in the egg stage on tree trunks and branches. In the spring, during bud break, light green larvae begin to hatch, which quickly grow and become viviparous females. During mass reproduction, aphids cover all leaves, shoots, and stalks with a continuous layer. The leaves do not curl, but a bluish coating of insect skins appears on them.
Mass development of the pest is observed in June-July. Most of the aphids fly from the plum to the reed at the end of July and stay there until autumn. After this, the winged females fly to the plum tree, where they lay eggs. Up to 10 generations of the pest develop in a year.
Plum gall mites and red fruit mites love plums; both insects are red-brown in color. The first pest forms growths (galls) at the base of the shoots. The insect overwinters in these galls, and in the spring (at a temperature of 15°C) it begins to feed on young plum shoots. During the summer, several generations of ticks hatch.
Fruit mite larvae hatch before plum blossoms and begin to feed on young leaves of the tree. Due to lack of nutrients, the fruits set poorly and soon fall off. In summer, mite eggs are clearly visible on the back of the leaf blade.
codling moth
This insect attacks plums from spring to late summer. The plum moth lays eggs more often inside the fruits, less often on the underside of the leaves. After just 2 weeks, caterpillars form from them. Their appearance usually occurs after plum blossoms.
Codling moth caterpillars feed on fruit pulp. Their waste products contribute to the appearance of diseases that cause the fruits to fall off. If you do not take rescue measures, the entire crop may die, and this despite the fact that only 2 generations of these pests change in one season.
A drop of gum appears on plums affected by the plum moth. This is a signal that the tree has been attacked by moths and needs to be saved. These red caterpillars are capable of chewing even the seeds of young plums. In ripe fruits, they eat away the pulp around the seed, and then begin to move closer to the petiole.
