Oriental hornet
| Oriental hornet | ||||||||||||
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Oriental hornet ( Vespa orientalis ) |
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| Vespa orientalis | ||||||||||||
| Linnaeus , 1771 |
The oriental hornet ( Vespa orientalis ) is a species of hornet . It is one of two species that occur naturally in Europe.
features
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Imagines of Vespa orientalis are great social wasps , they approximately reach the same height as the common European hornet ( Vespa crabro ). For workers, a body length of 25 millimeters is specified, for queens up to 35 millimeters. Workers in India are slightly smaller, queens 22 to 28 millimeters, workers 17 to 22 millimeters.
The species is usually distinctive because of its coloration and easily distinguishable from other hornets and social wasps. The body is mostly mostly brown in color and therefore lighter than in most other species, which have larger black proportions. Depending on the color variant, there are also animals with black-colored sections, especially on the free abdomen. Parts of the head (clypeus and frons) are yellow, the wings have a more or less intense brownish tint. The first tergite has two small yellow spots on the free abdomen, the third, usually also the fourth tergite, has a broad yellow band, often they are completely yellow in color. With Vespa crabro , the entire free abdomen, with the exception of the first tergite, is extensively colored yellow and black (not brown). The abdomen of the Asian hornet ( Vespa velutina ) introduced in Europe is predominantly black, with a wide yellow band on the fourth tergite, the other tergites only partially have a narrow yellow end border.
Vespa orientalis is the only hornet species that can withstand dry desert climates . The ability of the abdomen to act as a heat pump, which can be used to generate heat and also to cool the insect, contributes to this.
Color variations
Within the range of that Oriental hornet a number of color variants became known that the rank of subspecies described were. In analogy to the situation with other hornet species, it is probably just a matter of coloring varieties without taxonomic value.
- Vespa orientalis jurinei De Saussure, 1853. Albania. The free abdomen predominantly dark brown to almost black, only with two yellow spots on the rear edge of the first tergite.
- Vespa orientalis aegyptica André, 1884. Egypt. With larger yellow spots on the first abdomen stagite and predominantly brown colored fourth tergite.
- Vespa orientalis zavattarii Guiglia & Capra, 1939. Central Sahara (similar colors in Asia). Overall darker brown, with larger yellow spots on the first abdomen strait.
- Vespa orientalis somalica Giordahi-Soika, 1934. South Arabia and Somalia. Abdomen dark brown, almost black in color, with dark brown tinted wings. Very small yellow spots on the first tergite.
- Vespa orientalis arabica Giordani-Soika, 1957. Very similar to somalica , probably synonymous.
Special properties of the cuticle
It was not until 1991 that researchers at Tel Aviv University discovered photoelectric properties in the cuticle as well as in the cocoon of the larvae.
distribution
The oriental hornet inhabits a large area in the eastern Mediterranean region (Southeast Europe), in North Africa, the Near and Middle East, Turkey, Iran and India, east to the Himalayas. She was introduced to North America (Mexico). Other, isolated observations outside of the known distribution area (Madagascar, China) are attributed to individual animals that were dragged away.
The western edge of the distribution reaches Europe, here it lives in the southeast, on the southern Balkan Peninsula, north to Albania and Bulgaria, west to southern Italy, Sicily and Malta. It is widespread and quite common in the Peloponnese (southern Greece), it also occurs in Cyprus. In the east, in India, it is one of the widespread species and is particularly common in the Ganges plain . The easternmost deposits are in the foothills of the Himalayas, from West Bengal to Kashmir , with marginal finds from Nepal, Pakistan and Afghanistan.
Way of life
The species nests mainly underground, mostly in small mammal burrows, at depths of between 20 and almost 60 centimeters. In addition, there are also nests above ground, also in human structures. In large parts of its range, the species shows a preference for nesting sites in human settlements. A certain amount of inorganic components such as grains of sand is always stored in the nest shell. Most underground nests do not have a nest shell at all.
In Israel and Egypt, the young queens leave their wintering quarters in April to May (rarely in February), the first workers can be seen from the end of May to June. It has been observed that in the first nest phase, when the young queen is still looking after the first brood alone, other young queens enter the nest and try to drive away or kill the queen in order to take over the nest themselves. As soon as workers are present, however, this usually fails because they attack the intruder. It is therefore not uncommon to find dead young queens in the entrance area of young nests. Both queens rarely die in a fight, then after a while workers begin to lay eggs (only males can hatch). Normally workers prevent each other from laying eggs ("policing") and may eat eggs that have been laid. The colony grows quite slowly at first, with around 30 workers until mid-July.
The maximum size of the nest with around 2000 cells is reached in early September. The nest then comprises three to four honeycomb plates in Israel , four to ten in Egypt and regularly more than five honeycomb plates in India. The average number of workers will then be around 250, and will rise to over 400 by mid-September. The first large cells (for the production of new queens) are set up soon afterwards, the construction of small cells for female workers (and some of the males) is discontinued. In the final state, the proportion of large cells can reach almost a quarter. The first young queens fly around mid-October. At the beginning of winter (November, rarely until December) the nests die, only the young queens overwinter.
In summer, the animal often prey on the bee-eater that occurs in these regions , a swallow-like bird that establishes large colonies on steep walls. In summer, Vespa orientalis is one of the main food sources for bee-eaters in some regions. Oriental hornets are caught in the branches by large praying mantises, which in turn are well protected from the hornet sting by their armor .
It is unpopular with beekeepers because it also preyes on honey bees , and usually even directly on the apiary or beehive . The oriental hornet is therefore one of the worst beekeeping pests in its area of distribution , because it not only catches bees at the entrance hole, but it even penetrates weakened colonies and steals their honey .
Individual evidence
- ↑ Michael Archer (2005): Key to European Vespinae. BWARS Members' Handbook: 58-67.
- ↑ a b P. Girish Kumar, G. Srinivasan (2010): Taxonomic studies of Honet Wasps (Hymenoptera: Vespidae) Vespa Linnaeus of India. Records of the Zoological Survey of India 110 (Part-2): 57-80.
- ^ Jacob S. Ishay, Marian Plotkin, Natalya Y. Ermakov, Stanislav Volynchik, Zahava Barkay, David J. Bergman: The thermogenic center in social wasps . In: Journal of Electron Microscopy . tape 55 , no. 1 . Tokyo April 18, 2006, p. 41-49 , doi : 10.1093 / jmicro / dfl002 .
- ↑ a b c Michael Archer (1998): Taxonomy, distribution and nesting biology of Vespa orientalis L. (Hym., Vespidae). Entomologist's Monthly Magazine 133: 45-51.
- ↑ JS Ishay, T. Benshalom-Shimony, A. Ben-Shalom and N. Kristianpoller: Photovoltaic effects in the Oriental hornet, Vespa orientalis . In: Journal of Insect Physiology . tape 38 , no. 1 , January 1992, pp. 37-48 , doi : 10.1016 / 0022-1910 (92) 90020-E (This study includes a part of the Ph.D. thesis of A. Ben-Shalom).
- ↑ Ebrahim Ebrahimi, James M. Carpenter (2012): Distribution pattern of the hornets Vespa orientalis and V. crabro in Iran (Hymenoptera: Vespidae). Zoology in the Middle East 56: 63-66.
- ^ Libor Dvořák: Oriental Hornet Vespa orientalis Linnaeus, 1771 found in Mexico (Hymenoptera, Vespidae, Vespinae). Entomological Problems (2006) 36 (1), p. 80.
- ^ Anthony Gatt, Arnold Sciberras: The Oriental Hornet. timesofmalta.com, August 24, 2014 .
- ↑ Werner Arens: The social wasps of the Peloponnese (Hymenoptera: Vespidae: Vespinae, Polistinae), with a description of a new Polistes species and a regional Polistes identification key. In: Linz biological contributions. 43rd volume, issue 1, Linz 2011, pp. 443–481 ( PDF on ZOBODAT ).
- ↑ Michael Archer (2008): Taxonomy, distribution and and nesting biology of species of the genera Provespa Ashmead and Vespa Linnaeus (Hymenoptera, Vespidae). Entomologist's Monthly Magazine 144: 69-101.
