The European hornet ( Vespa crabro ) is Europe's largest wasp eusocial and the largest vespine in North America. This is actually the only bee found in North America. V. crabro is usually regarded as a pest by a human being in contact with it. Vespines, such as V. crabro , are known for making nests from surrounding plant material and other fibers to create complex paper nests. Unlike most other vespines, reproductive suppression involves policing workers rather than control of pheromones as previously thought.
These species sting in response to trampled or gripped, but generally avoid conflict. It also maintains its nest and can be aggressive around food sources. European wolves are mostly carnivores and hunt big insects such as beetles, wasps, large moths, dragonflies and mantis. They also eat fallen fruit and other sugary sources of food. Mutual predation between middle bee and robberfly (Asilidae) is often reported. Care should be taken when they are encountered in these circumstances, as they may sting without warning. The pain from the sting can last for several days with surgical swelling. The victim may wish to seek medical help in case of an allergic reaction.
Video European hornet
Taxonomy
The European Hornet is a true hornet (genus Vespa ), a group characterized by eusocial species. The genus is located in the subfamily of Vespinae, known to chew their food to feed their children and chew ingredients like paper to make their nests. According to a recent phylogenetic study, his closest relative is Vespa dybowski .
Subspecies
There are several subspecies of European hornet, mostly distinguished by geographic color shapes:
- V. c. altaica PÃÆ' Â © rez, 1910
- V. c. borealis Radoszkowski, 1863
- V. c. caspica PÃÆ' Â © rez, 1910
- V. c. chinensis Birula, 1925
- V. c. crabroniformis Smith, 1852
- V. c. crabro Linnaeus, 1758
- V. c. flavofasciata Cameron, 1903
- V. c. germana Christ, 1791
- V. c. oberthuri du Buysson, 1902
- V. c. vexator Harris, 1776, is found in the southern English county, and the European continent: This subspecies can be distinguished from the common European horns with its yellow head.
Maps European hornet
Description
The eyes V. crabro are very overhang and shaped like "C". The wings are orange red, while the petiolate stomach is striped brown and yellow. It has hair on the chest and abdomen, although the European wasps are not hairy like most bees. The typical mass size for the European Hornet is 477.5/- 59.9 mg. Because of this color and stomach pattern, V. crabro is often misunderstood as Asian giant hornet. In size, European hornet, with a length of 25-35 mm, is larger than ordinary wasps, but smaller than Asian giant horns. Women are usually larger than men in size and mass. However, the male stomach has seven segments, while the female belly has six segments. Only females have ovipositors (modified to form stingers), and men can not sting. The male antenna is slightly longer, with 13 segments compared to 12 segments in women.
Nest
Individuals usually live in paper nests, which consist of a flower handle (inner paper comb), envelopes, and a single inlet outside. Materials such as twigs, twigs, and other available plant sources are broken down, chewed, and shaped into nests by workers. These pieces are not uniform in shape, but are glued together very closely. Since social wasps generally prefer to build nests in the dark, envelopes are usually found around the nest to make them dark if the colonies can not find the dark spaces in which to build.
Construction
The nest consists of a mixture of paper-pulp made by female workers chewing dead skin, trees, or plant matter from the surrounding environment and mixing it with their saliva. To build a real comb, saliva is used as a cement to collect the organic and inorganic materials available to the colony. This cement not only brings together a comb, but also protects the comb from being damaged by water. This provides a protective barrier to help protect the colony from wind or other harsh weather conditions. The available resources, location, and amount of mastery affect the appearance of the final nest, so much variation is seen among the nests V. crabro .
Physical and chemical composition
Minerals such as titanium, iron, and zirconium are commonly found in the soil and they are also part of the comb wall. The average dry weight of the nest is about 80.87 g. Cells in a paper comb are usually 4 to 5 mm long and 8 to 9 mm in diameter. The composition of the nest elements in northern Turkey includes oxygen, carbon, and nitrogen as the main elements, while the elements found in small amounts are silicon, calcium, iron, and potassium, but no aluminum, magnesium, or sodium is detected, providing evidence further that European Bees use the surrounding land as a resource in building their nests. The ratio of fibrous material to actual saliva affects the ability of the nest to absorb water, so how well the inside of the nest remains dry. In nests studied in Turkey, fiber content is 23% while 77% is bee saliva. This combination results in optimal water absorption capacity.
Distribution
As the name suggests, European hornet, implies, V. crabro comes from Eurasia. Historically, the nest ranged from Japan to England. However, Saussure reported that V. crabro was introduced to North America in the mid-19th century, where it is now well established. In 2010, they were found in southern Guatemala. Some nests found in Guatemala are considered recently, incidentally, introductions, because this is the first documented occurrence.
Life cycle
V. crabro prefers to build nests in dark places, usually hollow tree trunks. Once the site is selected, the queen lays an egg in the comb inside the hive. Workers throw away eggs that are not laid by their queens; this behavior is called workers policing. Based on laboratory data, the spawning rate is about 2.31 eggs per day. However, in this same nest, the cell construction rate is only 1.63 cells per day.
V. crabro colonies change strategy on a seasonal basis to get food for larvae and adults. In April, when queens usually lay their eggs, the workers are actively going out and looking for food. Then, usually around autumn, the workers looking for a meal turned to scavengers. Instead of filing an effort to capture food sources, workers try to take what is more readily available. For example, European bees are seen hovering around garbage cans and picnic areas in the fall.
Work policing
Very few healthy laying eggs V. crabro colonies. While only the queens are mating and producing a fertilized female egg, the workers are able to lay the haploid male eggs. Workers are generally more closely related to the offspring of other male workers than the descendants of male queens. Workers will have reproductive benefits from spawning men, but do not do so. It was originally thought to be caused by pheromone control by the queen. However, new evidence suggests that this is not the case. Workers impose sterility on each other in a strategy known as workers policing. Workers either physically destroy the eggs that workers lay or discriminate against workers who are trying to lay their eggs. Ensuring that only the reproducing queen is considered to be beneficial to the organization and productivity of the colony as a whole, by reducing conflict.
Behavior alarm
Social hymenopteran species usually communicate with each other through behavior or pheromones. In European hornets, a typical alarm dance is performed outside the hive and consists of a consistent hum, racing in and out of the hive, and attacking or approaching the target pheromone alarm. The pheromone alarm is stored in, and secreted from, internal toxic pouches. 2-methyl-3-butene-2-ol is the main pheromone component that causes V. crabro to express this defensive behavior. Pentenols and other pentanols are contained in this venomous pouch, but the ultimate goal is most likely not to warn fellow bees that there is a danger nearby, because these chemicals do not cause alarm behavior.
Kleptoparasitism
European wolves have been observed to steal prey from spiders, which can be classified as examples of kleptoparasitism. This behavior was first documented in 2011 against the yellow garden spider, Argiope aurantia . Hornets are observed to fly into cobwebs and look entangled. However, the bee cuts off the free prey captured by spider webs. The spider does not attack or interfere with V. crabro because the wasp stole its prey. This behavior follows the pattern of most vespines changing their feeding techniques from food hunting to scavenging, especially once autumn begins.
In addition, V. crabro has been observed to attack the nest Polistes nimpha .
Relationships with humans
Endangered species and legal protection
Unreasonable fear of V. crabro often causes nest destruction. This has led to the decline of species, which are often threatened locally or even threatened with extinction. The European Hornets benefit from legal protection in some countries, especially Germany, where it has been illegal to kill European horns or nests since January 1, 1987, with a fine of up to EUR50,000.
Related matter
European bees are carnivores and eat many species of insects. Many of these insects are considered garden pests, which indicate that bees provide benefits to the farm or the average farm. However, they are also known "hawks" in the air for honeybees near their nests, which they then lower and consume. They can even kill honeybees inside their nests, if the bee colony is too weak for other reasons to protect itself. This, of course, produces fewer honey bees for pollination. The European wolf also tends to form a corset branch, which produces a dead branch.
Sting: case study
Most cases of sting from V. crabro do not require medical attention, but rarely can be serious. A documented case requiring treatment shows symptoms including tingling in the spot of sting, as well as headache and shortness of breath. At the hospital, the victim was found to have a rapid and irregular heartbeat with blood pressure of 111/63. The subsequent ECG shows atrial fibrillation with a rapid ventricular response. V. crabro contains toxic neurotransmitters such as dopamine, serotonin, and noradrenalineurotoxin apamine, as well as phospholipase A and hyaluronidase enzymes, histamine compounds, and melittin and bradykinin proteins. These compounds have been shown to cause episodes of tachycardia in smaller animals. The mechanism of attack described is still undetermined, but the victim may be abnormally susceptible to vespine stings. Currently, the two most effective treatments for reactions are electrical cardioversion or propafenone. The victims in this case study were given oral dose of propafenone (150 mg) and atrial fibrillation was completed.
See also
- Sting shock
- Vespidae
Note
External links
- the European horn protection site
- The European Hornet - The Fact Sheet of Penn State Entomology Department
- "European wolf and oak sap"
Source of the article : Wikipedia
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