The oak longhorn beetle is the main pest of oak wood.
By damaging the stem part, it sharply reduces its technical value. Lunardoni (1889) even cites a special rejection that is used in some places for materials damaged by oak beetle.
The passages of longhorned beetle larvae penetrate into the wood, often to the very core of thick oaks. In the Korabelny forestry, where especially large trunks are grown, we saw passages up to 50 cm long and 18 cm wide made in the wood of the trunk. The presence of such damage significantly reduces the yield of building materials, and with severe infection, oak becomes suitable only for firewood, and even then of the second grade. The loss of wood mass in the form of sawdust and chewing on some samples reaches 35%.
The loss of wood mass was determined by immersing it in water and comparing the volumes of displaced water on two equal-sized samples of damaged and healthy oak trees.
In addition, according to the literature, damage to the oak longhorn beetle serves as a route for the penetration of wood-destroying fungi into the wood, causing the so-called “red rot” of oak (Lunardoni, 1889), blackening of the walls of the passages (Ratzeburg, 1839, 1844), as well as further damage to the trunk by ants ( Keller, 1885).
Indeed, all these phenomena take place in our forests.
The least harmful consequence of oak beetle damage is, perhaps, blackening of the walls of the passages, since it is not observed in deep wood, but is confined only to the surface layers of it in the passages and, moreover, only slightly affects its mechanical strength. The nature of this phenomenon has not yet been sufficiently studied.
The loss of mechanical strength of damaged parts of the trunk or branches is much more important. The phenomenon of branches, tops and even entire trunks damaged by longhorn beetle larvae breaking off is quite common, especially in the forests of Crimea.
We even had to observe the “winding” of oak trunks, caused by the gnawing and destruction of the root paws and butt part of the trunk by the passages of the barbel. In some cases, fairly large oaks aged 60-130 years lost their mechanical strength and stability to such an extent that they easily fell out when pressed with a shoulder.
However, the most common and, perhaps, the most harmful consequence of damage to a tree by a longhorn beetle is that fungi easily penetrate into the tree through its passages, ultimately destroying the wood.
The colonization of infected trunks by ants has both positive and negative implications. On the one hand, it is useful in that the longhorned beetle cannot stay in the area where the ants settle, since its larvae are destroyed by the ants, and only pupae or beetles can be preserved under the protection of the lime cap in the passages. On the other hand, the ants themselves completely destroy the damaged wood. Most often, ants use stumps or only the very bottom part of the trunk for their settlements.
Longhorn beetle damage has a very adverse effect on the condition of plantings in some areas, providing a temporary shelter for some very harmful insects. In particular, barbel passages are often used for laying eggs by gypsy moths in the plantations of the Transcarpathian region and in the Crimea.
Damage to single oak trees in Chernolesskoye, Chigirinsky and neighboring forest districts has been noted for a long time, although the cause of this phenomenon has not been precisely established.
Also in late XIX Art. attempts to grow thick timber and promote natural regeneration by leaving single trunks in cutting areas were considered unsuccessful.
As a result of the sharp lightening, the trees left in the cutting areas were covered with water shoots, dead tops, and after a few years, as noted in many forest management reports, they became suitable only for firewood. The loss of technical qualities of old oak trunks when they are left as seed trees is caused by damage from the oak longhorn beetle. When analyzing some of the infected trees, we established from the newly grown layers of wood on the damaged areas that these trunks were infected with the longhorned beetle back in 1844.
The oak longhorned beetle has also settled in the Korabelny forestry for a long time. Even during the examination of old oak stumps of a 50-year-old plantation, carried out in 1931, barbel burrows were discovered on them. Thus, the infestation of these stumps dates back to the period 1870-1875.
In the period from 1920 to 1926. The damage caused by the longhorned beetle has increased dramatically. A number of forestries received complaints about damage caused by the longhorn beetle, which greatly reduced the yield of valuable export timber needed at that time for our country, which constituted a serious item in the general balance of our exports and the foreign exchange fund.
In 1926, N.S. Grese was sent to survey Chernolesskoye and neighboring forest districts. Based on the survey materials, N.S. Grese planned to cut down all trees damaged by the longhorn beetle, and in particular, completely cut down the infected wings of the square. 76 Chigirinsky forestry and kv. 256 Chernoleskoe forestry. Due to the breeding of the longhorned beetle, sq. m. were also cut down in the Nerubai dacha. 63 and some areas of the square. 4, 56 and 95.
Thus, barbel damage in that period caused significant damage to forestry.
The most heavily contaminated areas in the Chigirinsky forestry were the plantings of the Matreninskaya and Matveevskaya forest dachas with old single oak trees in twenty-six blocks. In addition, the bush plantings, as well as the southern and western edges of the plantings bordering the old cutting areas, were heavily contaminated, covering a total area of 2,700 hectares.
In the Chernoleskaya dacha, which suffered the most from damage from the oak longhorn beetle, the main breeding grounds of the pest were in the old scenes in thirty-two blocks. In addition, the southern and western edges of plantations located along the border with old clearings were severely damaged, covering a total area of 2017 hectares.
In the Chutyansk forest dacha, in addition to the old wings, the testes in a number of quarters were heavily infested with longhorned beetle.
In the Nerubaevskaya forest dacha, the most contaminated plantings were the old bushes and the cleared edges of the plantings along the borders with clearings. In addition, the plantings of the former Mikhailovskaya Dacha on an area of about 400 hectares were severely damaged.
In the Krasny Nerubai dacha, the oak longhorned beetle has multiplied in the old scenes and along the edges of the plantings.
Not included in this list big number"young" scenes embedded in last years before the examination, in which the oak longhorned beetle has not yet had time to reproduce to a large extent.
In the Kamensky forestry, stands damaged by longhorn beetle were found in the Kholodny Yar tract, in thinned stands with overmature oaks, as well as on old seed trees in twelve blocks on a total area of 500 hectares.
In the Smelyansky forestry, the oak longhorned beetle multiplied mainly on single oak trees in Sunkovskaya, as well as in Vladimirskaya forest dachas, on a total area of 950 hectares.
In the Kremenchug forestry, a small breeding center was discovered in the Glinskaya forest dacha in the old wings on an area of 30 hectares.
In the Bershad forestry, the oak longhorned beetle has multiplied in the artificially thinned plantings of the Obodovskaya forest dacha on an area of 55 hectares. According to a survey in 1947, oak longhorn beetle was found in the Obodovskaya dacha in the Rogi tract on individual 200-400-year-old overmature oaks with a diameter of over 1 m, heavily worn down by longhorned beetle larvae. In total, there were 15-20 such oaks weighing up to 200 m 3.
In the Rudnitsa forestry, according to a survey of 1947, in the oak plantation adjacent to the Rudnitsa railway station, on an area of 4 hectares, there was a significant number of infected and drying oaks.
In the Korabelnaya dacha of the Korabelny forestry, the longhorn beetle damaged exclusively single oak trees (seed trees and reserve trees) in fifty-five blocks, on an area of 3,500 hectares.
In the Mukachevo forestry, the oak longhorn beetle is widespread in all old and middle-aged plantations on individual old trees in the Palatska, Chipkesh, Makosh-Dozuptovo, Felsherde, Gossugaz tracts, with a total mass of up to 5000 m 3.
In the Beregovskoye forestry, the main breeding grounds of the oak longhorn beetle are concentrated in the Loposh, Atak, Nadierde tracts, and the Makaryevskaya Dubina urbarial forests, which are old and overmature thinned oak plantations. In addition, there are individual infected trunks in the Roman-Liget and Rafailovo tracts, covering an area of 1000 hectares.
In the Shalankovsky forestry, old thinned oak plantations are located on the mountain slopes of the Gelmets tract, and single infected trunks on an area of 30 hectares are located in the Mochar and Velikiy Les tracts.
In the Vinogradovsky forestry, the open spaces of the old oak forest in the Veryatskaya Urbaria and Gorbki tracts on an area of 30 hectares are heavily contaminated.
In the Hu stack forestry, the oak longhorn beetle was found in significant amount on individual old trunks in the tracts of Kolorun on Skordano over an area of 6 hectares and on single infected trunks in the tracts of Sumny Zvor, Mat-Galat, Rinovets, Gomba, Nat-Gat, Danilovsky Verkh, Petrunas, Katunskie Puti, Verkh.
In the Uzhgorod forestry enterprise there are also areas of old oak plantations heavily infested with barbel. In addition, trunks infected with oak longhorn beetle are found in oak forests of the Chernivtsi region. According to the forest pathological inspection report, there are trunks damaged by oak longhorn beetle in the Khotyn and Chernivtsi forestry enterprises.
The total area of heavily infested oak longhorn beetle plantations and single trees in Ukraine in the pre-war years was 11,000 hectares weighing 1,500,000 m 3 .
If you find an error, please highlight a piece of text and click Ctrl+Enter.
A- bug; b- doll; V- larva; G- damage
Damages Oak trees of different ages, hornbeam, pear, less often - chestnut, beech, elm. Occupies weakened, diseased trees, freshly cut trunks, windfalls, and fresh stumps. Dangerous for young trees.
Distributed in the European part of Russia, the Caucasus, Crimea and Belarus.
Bug(9 - 20 mm long) black, with a characteristic pattern of dense yellow hairs on the pronotum, above the wings and abdomen. The antennae (shorter than the body) and legs are reddish-yellow. The elytra are rounded at the tip, covered with short and dense brown or black hairs, with yellow spots on the suture behind the shield, and at the tip - three yellow stripes: the first is short and located in front of the middle, the second is behind the middle, the third is lower. The pattern on the elytra is very variable.
Egg(length 1.5 - 1.9 mm, width 0.6 - 0.8 mm) elongated-elliptical, white, shell without structure. They are located in crevices in the bark along the entire trunk, singly or 2-3 together, sometimes in small groups.
Larva(18-30 mm) pale yellow, taller than wide, the front part of the body is flattened. The head is small, retracted into the prothorax. The mouthparts are brown, the upper jaws are almost black and shiny. The legs are rudimentary, very short. The dorsal calluses are large and slightly protruding. The abdominal segments are separated by deep constrictions.
Doll ocher-yellow, head with irregular constrictions and small teeth on the sides. The antennae reach the base of the hind legs.
Years beetles in May - July. The average fertility of one female is 62 eggs. The larvae first live in the bark, then between the bark and wood they make winding, gradually widening passages. The stroke length reaches 40 cm or more. By the end of summer, the larva goes into the wood to a depth of 5 cm, making a hooked passage.
Overwinter larvae in pupal cradles, separated from the passage by a plug of large shavings.
Pupation in the spring in wood. The pupal phase lasts about 20 days. Young beetles fly out through the entrance hole gnawed out by the larva.
Generation one-year
Supervision carried out simultaneously with supervision of other species of longhorned beetles. If it is discovered that it is necessary to carry out detailed censuses, they are guided by the following criteria: 0.6 or more larvae or 0.5 or more flight holes per 1 dm 2 of the populated part of the trunk is considered as high level pest population.
The longhorned beetle family unites about 17 thousand species of beetles, of which 1,500 species are chewed in Russia. Longhorned beetles feed on plants, and most of the longhorned beetles live off trees and shrubs and are called lumberjacks.
The sizes of longhorned beetles range from 3 to 60 mm, their body is elongated, most often covered with hairs. The legs of beetles are long, the tibiae have spines, and the tarsi consist of 4-segments. The head of insects is free, their antennae are longer than half the body and often exceed it by 1.5-2 times.
All woodcutter beetles can extend their antennae onto their backs. Elytra cover the entire abdomen; occasionally the elytra are greatly shortened and the abdomen remains partially uncovered (short elytra of the longhorned beetle of the genus Molorchus, etc.). Most longhorned beetles are capable of producing a squeaking sound when the mesothorax rubs against the prothorax.
Black coniferous longhorned beetles(genus Monochamus). Black coniferous longhorned beetles have large body sizes, which are always more or less elongated. It is most often shiny, black or pitch black. The elytra are long, in most cases strongly elongated, slightly tapering towards the end, usually rounded, with rough sculpture and dense, lighter hairs. The antennae are more or less thin, 1.5 times longer than the body, with one segment strongly thickened.
Common in Russian forests the following types black barbels:
Black large pine longhorned beetle (Monochamus urussovi Fisch.)
The greatest harm occurs in the forests of Siberia, Altai and Far East, breeding in huge numbers in the foci of the Siberian silkworm and the fir moth, in burnt areas, as well as in lumberyards and logging sites.
In the European part of Russia, this species is widespread in the northern part of the forest zone and is relatively rare in its southern part.
In the hotbeds of the Siberian silkworm big barbel First of all, it colonizes fir, then spruce, larch and cedar. It prefers trees with a diameter thicker than 24 cm, and avoids thin trees (8-12 cm).
The large black longhorned beetle not only destroys wood, but is also a very dangerous pest of growing forests. Initially, the longhorned beetle reproduces in plantings damaged by the Siberian silkworm. After the insect population reaches a high number, longhorned beetles rush to neighboring, healthy forests for additional food and weaken them by gnawing most of the branches that dry out. Plantations damaged by beetles lose their value for exploitation, since the yield of wood is negligible.
Black small pine longhorned beetle (Monochamus sutor L.)
Black small coniferous beetle(Monochamus sutor L.) usually accompanies the large one, but in some cases it reproduces independently, causing the same damage as the large black longhorned beetle.
In Eastern Siberia it is the most common and dangerous pest of larch. In Yakutia, the small black coniferous longhorned beetle makes up 67% of the total number of black coniferous longhorned beetles. In Kamchatka, only the small black coniferous longhorned beetle is found.
The beetle is also widespread in spruce forests of the European part of Russia, especially in areas of root fungus, where it causes great physiological and technical damage. The biology of this species is similar to that of other black longhorned beetles, but it also has its own characteristics. The black small coniferous longhorned beetle prefers to colonize felled wood in illuminated areas, cutting areas and warehouses, and standing trees - in thinned out plantings, in open spaces, as well as along the edges of the forest.
Black pine longhorned beetle (Monochamus galloprovincialis Germ.)
(Monochamus galloprovincialis Germ.) is a pest pine forests in the southern part of the forest zone, forest-steppe and steppe zones s of the European part of Russia, belt burs Western Siberia. It reproduces in pockets of root sponge, in burnt areas, in pockets of pine-eating insects, bark bugs, in pine forests weakened by drought, in logging sites and in timber warehouses, where it colonizes timber and large logging residues.
 |
Velvet-spotted black pine beetle (Monochamus saltuarius Gelb.)
Velvet-spotted black pine longhorned beetle(Monochamus saltuarius Gelb.) is widespread in the European North and throughout Siberia, as well as in Europe. It colonizes mainly freshly cut wood, logging residues and dying trees of all types. coniferous species.
Speckled black pine beetle (Monochamus impluviatus Motsch.)
Speckled black pine beetle(Monochamus impluviatus Motsch.) is found in the forests of Siberia, but its numbers are insignificant compared to previous species, and therefore the damage caused is small. Prefers larch.
Tetropium barbels (genus Tetropium)
Longhorned Tetropium(genus Tetropium). Longhorned beetles - tetropiums are characterized by small in size and the flattened body of beetles. The antennae reach half the body, the pronotum is almost as long as it is wide, the elytra are barely convex, moderately long, parallel, usually much wider than the pronotum, rounded at the apex, black or chestnut; body black. Several species of longhorned beetles of this genus are common in the forests of Russia.
Shiny-breasted spruce beetle (Tetropium castaneum L.)
(Tetropium castaneum L.) has a black body, brown or black elytra, each with 2-3 longitudinal lines. The pronotum is shiny in the middle, sparsely punctate. The length of the insect is 9-18 mm. The larvae emerging from the eggs gnaw out wide tunnels under the bark. irregular shape, deeply touching the sapwood. After 20-25 days, the larvae go into the wood, where they make hook-shaped passages up to 8 cm long.
At the end of such a passage, the larvae overwinter, closing it with a plug of sawdust. In the spring, the larva of the spruce longhorned beetle pupates, and the hatched beetle emerges through the entrance hole of its own larva, which it gnaws, transforming it from a flat slit into a rounded-oval one, which also differs from black longhorned beetles.
Gray long-horned beetle (Acanthocinus aedilis L.)
Gray long-whiskered beetle ( Acanthocinus aedilis L.) is the most common inhabitant of pine forests. Found everywhere in large quantities, but usually attacks fallen trees, stumps, windfall and windbreaks. However, it does not harm the felled wood, since the larva gnaws wide, irregularly shaped tunnels in the bark and phloem without touching the wood.
When in large numbers, longhorned beetle larvae eat away at the entire under-roof space, filling it with compressed brown sawdust and thereby preventing the settlement of other species that damage the wood. Other species of this genus also do not cause noticeable technical harm.
Ribbed ragium (Rhagium inquisitor L.)
Usually lives together with the gray long-whiskered beetle ragy ribbed ( Rhagium inquisitor L.), which has the same development cycle. Its larvae live and pupate under the bark, so it does not damage or destroy wood.
Black ribbed lumberjack (Asemum striatum L.).
Black ribbed lumberjack(Asemum striatum L.). The beetle is black, body length 12-22 mm. The elytra are convex with longitudinal parallel ribs (transversely wrinkled between them), with dense fine punctures. The antennae are short. Most often, they jointly colonize stumps and the butt part of drying trees, as well as unbarked logs used for sleepers and telegraph poles.
Short-winged spruce longhorned beetle (Molorchus minor L.)
Widely distributed throughout the world short-winged spruce beetle(Molorchus minor L.). In this beetle, the elytra extend only to half of the body. The membranous wings are clearly visible from underneath them. Therefore, from a distance it looks a little like a membranous insect. Its larva bores narrow, deep transverse passages under the bark of thin spruce trees, less often pine trees, ending with a hook in the wood. Longhorn beetle damage can be found on wooden fences, pole stacks and other round timber. Causes relatively little damage to wood.
Brown butt barbel Arhopalus (-Criocephalus) rusticus L.
One of the most common longhorned beetles living off coniferous wood is brown butt barbel Arhopalus (-Criocephalus) rusticus L.
This large beetle (length 9-27 mm) has an elongated dark brown body with a reddish or chestnut tint. The antennae are short, no longer than half the body. The elytra are slightly convex, with more or less developed longitudinal ribs, densely double punctured, and covered with small brownish hairs.
The brown butt beetle prefers pine and can colonize dry wood, causing damage to cold buildings, sleepers and telegraph poles. Probably, their colonization occurred while the logs were in the bark, and the emerging larvae then continued to live in the mentioned objects and feed on wood for several years. The barbel also brings indirect benefits. By colonizing stumps, it accelerates their destruction and thereby contributes to the rapid involvement of organic matter into the biological cycle.
Great oak longhorned beetle (Cerambyx cerdo L.)
Most hardwoods are damaged by many types of longhorned beetles. Thus, valuable oak wood contains larvae of beautiful, very large (up to 65 mm long) large oak longhorned beetle(Cerambyx cerdo L.). Its passages sometimes reach a length of 50 cm and a width of 2.8 cm. Currently, the large oak longhorned beetle is rare and will probably soon be classified as an endangered species.
Giant woodcutter (Callipogon relictus Sem)
In the Ussuri region, they live on oak and other deciduous trees. giant lumberjack Callipogon relictus Sem. This is the largest barbel in Russia. It reaches a length of 9.5 cm, the larva is 14 mm. Currently, it is classified as a rare, protected species of fauna. Trees inhabited by it should be protected.
Lesser oak longhorned beetle (Cerambyx scopolii Fussl.)
Lesser oak longhorned beetle(Cerambyx scopolii Fussl.) is common in oak forests of the forest-steppe and steppe zones. Beetle 17-28 mm long. The body is one-color, pitch-black, moderately shiny.
In addition to oak, it damages beech, hornbeam, ash, maple, elm and fruit trees. Causes relatively little harm, since it usually does not reach high numbers, although, unlike previous types This genus inhabits fallen trees and timber.
Longhorned barbel (Parandra caspica Men).
Typical technical pests of oak wood in cutting areas and timber warehouses are variegated oak beetles, from a distance slightly reminiscent of wasps in coloring. The body is black with arcuate yellow stripes in one species (Plagionotus arcuatus L.) and wide yellow constrictions in another (Plagionotus detritus L.). The generation of motley longhorned beetles is one-year. These species are very widespread, numerous and cause great technical damage wherever oak wood is available.Gray aspen clit (Xylotrechus rusticus L.)
Causes great technical damage to birch, aspen, alder and beech wood gray aspen cleat(Xylotrechus rusticus L.). This is the most widespread and numerous inhabitant of deciduous forests and timber warehouses.
The beetle is about 20 mm long, black, with three broken transverse gray stripes on the elytra and gray spots on the prothorax formed by hair.
Great aspen beetle (Saperda carcharias L.)
Great aspen beetle(Saperda carcharias L.) is widespread in the European part of Russia and Siberia. Beetle 21-28 mm long. Light brown or gray due to the hairs covering it. The last antennal segments have black rings. The large aspen longhorned beetle causes significant technical damage, because after cutting down trees, the lower part of the tree trunk turns out to be worn away by larvae, and above it is affected by redness and central rot, the causative agent of which penetrates through the longhorned beetles' passages.
Marbled barbel (Saperda scalaris L.)
Marbled patterned barbel(Saperda scalaris L.) also inhabits birch, aspen, alder and a number of other deciduous trees. Technical damage consists of damage to the wood by the passages and staining it with fungi that are introduced through the passages. The beetle is greenish in color with black spots on the elytra, forming a marble pattern. The length of the beetle is 12-20 cm.
Other types of longhorned beetles
A number of longhorned beetles settle on weakened and fallen oak trees, the larvae of which gnaw rather deep holes in the wood. These longhorned beetles open the gates of fungal infection and greatly reduce the technical quality of wood harvested during sanitary logging. The main types are: Köhler's red-winged longhorned beetle Purpuricenus Kaehleri, red oak woodcutter Pyrrhidium sanguineum L., red barbel antelope Xylotrechus antilope Schonh.
Softwood wood is damaged by many types of longhorned beetles. Poplars, aspens and willows are especially badly damaged. Large barbels settle in the lower part of the trunks of these rocks: willow woodcutter - fat man(Lamia textor L.) and green musk beetle(Aromia moschata L.), in the middle and upper parts of the trunks - small species.
To get to know amazing world bugs, no need to travel to tropical countries. To do this, just read this book. Its author, Doctor of Biological Sciences S.S. Izhevsky, talks in a lively and fascinating manner about the most common and typical beetles for the fauna of Russia, of which there are about 20 thousand in total.
The world of beetles is diverse, among these insects there are predators and vegetarians, giant beetles and small beetles; some can fly beautifully, others move exclusively on foot, and there are also amphibious beetles that can exist both on land and under water.
You will get acquainted with the history of each beetle, learn about how they mix across countries and continents, about their behavior and lifestyle, and get a lot more interesting information.
The book is beautifully illustrated and addressed to a wide range of readers.
Book:
| <<< Назад
|
Forward >>> |
This is one of the most famous representatives woodcutter beetles. Within the former USSR, the genus Cerambyx is represented by seven species. The most famous of them, if not famous, is the barbel.
It is famous not only for its impressive size - adult beetles reach 65 mm in length - but also for its beauty and at the same time the harm it causes.
Like many movie stars or pop artists, the mustache is not content with one name and often appears in literature under “pseudonyms.” They call it oak barbel, large oak barbel, common black oak barbel, craftsman barbel. In Ukraine, in a number of places, the beetle has very strange names: chamois and even knight.
Spreading. In addition to Russia, Ukraine and Transcaucasia, the large oak barbel is found in Western Europe, North Africa, Iran and Turkey.
External signs. The beetle itself is pitch-black and shiny. The black elytra are smooth and only visible at the apex hairline, which has a reddish-red tint.
Our hero has a magnificent mustache. In females they are equal to the body length, and in males they significantly exceed it. Just like the beetle's abdomen, the antennae are silky to the touch. Their first segment is densely and strongly punctured and therefore looks matte; the second segment is almost the same in length as in width. These characteristics distinguish the great oak longhorned beetle from other representatives of the same genus, and taxonomists use them in their identification tables.
The adult larva reaches a gigantic size for representatives of our entomofauna - 90 mm with a width of 18–20 mm. J. Fabre compared them to “crawling pieces of intestine.” Brown or reddish head with three eyes, very small. But it has powerful black upper jaws. The fleshy yellowish-white larvae have a very large prothorax.
The larva's legs are small - and it doesn't really need them. Inside the passages in the wood, the larvae move with the help of special growths on the dorsal and ventral sides, which are called calluses.
Lifestyle. The longhorned beetle prefers very sparse oak forests with isolated trees to dark, dense forests with regrowth and undergrowth. It is often found in tree stands that have been lightened during logging. Prefers to inhabit old oaks aged 120–140 or more years with thick, cracked bark.
Occasionally, the longhorned beetle settles on other deciduous trees and bushes: walnut, chestnut, beech, ash, pear, apple, hazel and hawthorn. When choosing a bush, the female is clearly making a mistake. Although an egg can be laid on one of them, it is unlikely that the larva that emerges from it will be able to complete development on it and turn into a full-fledged beetle.
The flight of beetles begins in May and continues until July. Beetles usually fly during the day. Although in warm weather you can occasionally see a barbel flying with a roar, like a strategic bomber, in the evening.
A sure way to find a handsome one is to carefully examine the oak trees, from whose trunks gum sap flows. It’s his smell that usually attracts them to feast on something sweet (remember the stag beetle?). Later, having colonized the tree, the longhorned beetles themselves provoke gum production. As if anticipating its imminent death, the tree begins to “cry” - secrete juice from the fresh flight holes of the beetles.
One of the most important conditions The choice of food substrate for the oak longhorn beetle, and other wood-boring beetles, depends on the quality of the tree being inhabited. The vast majority of species settle in dead wood or wood that has begun to rot. Only a few are able to develop from living tissue and inhabit relatively healthy trees. It is these species that claim to be the most serious physiological pests. These include the large oak barbel.
The larva slowly crawls in the depths of the wood, literally eating its way through. With its strong jaws, it bites off piece by piece from the body of a powerful oak tree and swallows it. The larval passages are oval in diameter; they are filled with brown wood shavings mixed with excrement.
In the third summer, the larva completes its development and, already in mid-June, begins to prepare a “springboard” for its release next spring. Shortly before pupation, it changes the direction of its move, rushing towards the bark, and at the end it gnaws out the cradle. But first, the larva makes an exit hole in the bark and immediately clogs it with a plug of coarse wood particles and delicate fibers. And only after that it pupates.
The total length of the stroke by the end of the larva’s life can reach 1 m!
In the spring, the beetle that emerges from the pupa will only have to gnaw through a very thin partition, “knock down the door” with its forehead and get out into the wild. Thus, the development of the oak longhorned beetle lasts 3 years.
Role in nature. Of all oak wood pests, this species is the most dangerous. Physiological harm is noticeable already in the second year of larval life. When a tree is heavily infested, the foliage changes color and wilts. The ends of the young shoots dry out and dryness appears. The technical damage caused by the longhorned beetle is very great. Etched by larval passages the most valuable wood Only suitable for firewood.
It is difficult to fight oak longhorn beetle.
HARM CAUSED
Dangerous pest of oaks. Nowadays it is rare. Included in the Red Book.
Ordinary trapping trees are not suitable for this, since the longhorned beetle, as a rule, does not lay eggs on cut down or lying trees. Previously, at the time of the existence of vast old oak forests, they first of all tried to cut down trees infected with longhorn beetle and immediately after cutting down all oak stumps were uprooted or sanded.
Now the times have come. Perennial oak forests - the former beauty and pride of Russian lands - have disappeared. After all, they once approached Moscow itself from the south.
The hero of our story, the large oak barbel, has also become rare. Since the early 80s, along with a number of other wonderful animals, it has been included in the Red Book as a species that is declining in number and subject to protection. So the former pest found himself under state protection.
| <<< Назад
|
Forward >>> |
Imago. The beetle is pitch black in color. Body size up to 65 mm. The elytra are rufous in the apical part. The antennae are longer than the body. The pronotum is covered with rough, black folds.
The suture angle of the elytra is equipped with a spine. The length of the second antennal segment, measured along the inner edge, is equal to its width. The top is covered with indistinct hairs. Only the apex of the elytra has denser and more noticeable hairs. The Crimean and Caucasian populations are distinguished by coarse wrinkled pronotums and elytra strongly tapering towards the rear.
Sexual dimorphism. Individuals of different sexes differ in the structure of their genitalia. Secondary sexual characteristics are not expressed.
Egg, like all barbels, elongated-oblong in shape, more narrowed and narrowly rounded towards the caudal end. At the anterior cranial end it is obtusely rounded. The length is more than twice the width.
Larva. Length at the last age is up to 90 mm, width - up to 20 mm. The pronotal shield is covered with rather coarse shading.
Clypeus and upper lip of larvae, as in all individuals of the subfamily Cerambycinae, narrow, occupy about a third between the mandibular condyles. The cutting edge of the mandibles is smooth, chisel-shaped, and has no teeth.
The foramen magnum is separated by a thin bridge. There is a postnotum. The labiomaxillary complex is connected to the anterior edge of the hypostome at small area, slightly exceeding the width of the gula. Abdominal segment IX has no weapons.
Doll, like all barbels, is of an open type with freely located external organs. The head is clearly visible, the cervical interception is pronounced behind the eyes. Oral appendages, antennae, legs, wing rudiments, and an open, mobile abdomen are also clearly visible. The integument is white, translucent and bears inconspicuous setae, only more or less densely located in some parts.
The antennae of the oak longhorn pupa do not have spines on the lateral side. The apex of the abdomen is without urogomphal processes. The top of the hind thighs is bare. The pronotum near the apex has no transverse interception.
Development
Imago. The beetle flight is observed from mid-May to August inclusive. Individuals are photophilous. They predominantly settle in old plantings of coppice origin. Here they inhabit the well-lit and thickest living oak trees, located on the southern edges and in thinned forest stands.
Mating period. Females lay eggs in cracks in tree bark. Fertility up to 100 pieces.
Egg. Embryo development lasts 10 - 15 days.
Larva after reflection it immediately penetrates under the bark. In the first year of life, it gnaws out a hole under the bark. Before the first winter, the larva goes deep into the wood and spends the next two years there. At the same time, it gnaws out deep tunnels, the width of which can reach 3 cm. In the third year of development, after wintering, the larva brings the tunnel close to the surface of the trunk and pupates.
Doll. Duration of development is 1 - 2 months.
Imago. Young beetles hatch towards the end of summer, in July-August, and overwinter in the larval tunnels. They leave the tree only in the spring. Before mating, they undergo additional feeding with oak sap.
Features of development. The generation is three years old.
Morphologically related species
According to morphology ( appearance) imago is close to the described pest Small oak longhorned beetle ( Cerambyxscopolii). The main differences: the antennae are noticeably, but not more than 1.5 times, longer than the body; the second antennal segment is narrow, ring-shaped, almost three times as wide as it is long; body color is black without a brown tint; body size does not exceed 28 mm.
In addition, the species is divided into two subspecies Greater oak longhorned beetle ( Cerambyxcerdocerdo) and Southern Great Oak Longhorned Beetle ( Cerambyxcerdoacuminatus) are similar in adult morphology.
In the large oak longhorned beetle, the elytra are weakly narrowed in the posterior part, and the pronotum has a rough, irregular, transversely folded, grooved sculpture.
The southern large oak longhorned beetle is distinguished by its elytra tapering towards the apex, the pronotum is covered with a rough and irregular sculpture, the grooves and folds of which are connected and often merge into each other.
Geographical distribution
Oak barbel found in oak forests of Russia, Ukraine and Georgia. Its habitat includes Crimea, the Caucasus, and Western Ukraine. Now is rare species and needs protection.
Maliciousness
The oak longhorn beetle damages hardwood. Prefers coppice oak. The larvae are harmful.
As a result of the pest's activity, trees weaken and lose resistance to adverse factors. environment, and the category of technical suitability of wood is also reduced.
Control measures
Supervision
Timely organization of reconnaissance and detailed supervision by categories of tree condition.