The Oriental hornet (Vespa orientalis) is a social insect species of the family Vespidae. It can be found in Southwest Asia, Northeast Africa, the island of Madagascar (but no reports have been made of its presence on the island for many years), the Middle East, Central Asia, and parts of Southern Europe. Oriental hornets have also been found in a few isolated locations such as Mexico and Chile due to human introduction. The Oriental hornet lives in seasonal colonies consisting of caste system dominated by a queen. The hornet builds its nests underground and communicates using sound vibrations. The hornet has a yellow stripe on its cuticle (exoskeleton), which can absorb sunlight to generate a small electrical potential, and this might help supply energy for digging. The adult hornet eats nectar and fruits and scavenges for insects and animal proteins to feed to its young. Because they are scavengers, the hornets may also serve as a transmitter of disease following consumption of infected plants. The hornets are a primary pest to honey bees, attacking bee colonies to obtain honey and animal proteins. The sting of an Oriental hornet can be quite painful to humans and some humans are allergic to stings.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThe adult hornet has two pairs of wings and a body measuring between 25 and 35 mm (0.98 and 1.38 in) long. Drones and workers are smaller in size than the queen. V. orientalis is a reddish-brown color and has distinctive thick yellow bands on the abdomen and yellow patches on the head between the eyes. It has very strong jaws and will bite if provoked. Females (workers and the queen) have an ovipositor, which is a specialized organ shaped like a tube that is used for laying eggs. The ovipositor extends from the end of the abdomen and is also used as a stinger.Males (drones) can be distinguished from workers by the number of segments on their antenna. Drones have 13 segments, while workers only have 12.The Oriental hornet looks similar to the European hornet (V. crabro) and should not be confused with the Asian giant hornet (V. mandarinia) of East Asia.
Oriental hornets can be found in Central Asia, southwestern Asia from Armenia and Turkey to India and Nepal, throughout the Middle East, in Northeast Africa, in some Afrotropical countries such as Ethiopia and Somalia, and in parts of Southern Europe: Croatia, Bosnia, Montenegro, North Macedonia, Albania, Greece, Spain, Bulgaria, Cyprus, Malta, Sicily and the southern half of peninsular Italy. Oriental hornets have been introduced by humans into additional locations, including Chile, Madagascar, Mexico, and Xinjiang, China, as well as the occasional introduction via fruit into Belgium and the United Kingdom. The Oriental hornet is the only member of the genus Vespa that can be found in desert climates such as those in North Africa, the Middle East, and parts of southwestern Asia.
V. orientalis is a type of social wasp. Individuals live collectively in colonies with one queen and thousands of workers. Social wasps are unusual in their practice of altruism in which nonreproductive individuals work for the benefit of the colony. This occurs because all individuals in a colony are closely related.
Within a colony, the caste system is dominated by the queen that is the only reproductive female in the colony. Subordinate to the queen are the workers (daughters) and drones (sons). Like the queen, drones solely serve reproductive roles. The workers are responsible for the rest of the labor. Workers specialize in the performance of different tasks. Workers are responsible for foraging for food, providing shelter, defending the colony, and caring for the colony's brood, which consist of the queen's offspring.
Oriental hornets communicate through sound vibrations. The three main types of vibrations used to communicate are taps to the queen, awakening taps, and larval hunger signals. When workers tap while facing the queen, three effects are noted: the queen starts to search the combs for vacant cells in which to lay her eggs in, the workers go back to performing their typical duties, and hunger signals by larvae cease immediately and are not resumed for at least 30 minutes. The main purpose of these taps seem to be to encourage the queen to lay more eggs. Awakening taps by workers cause a general intensification of activities in the colony. The effects are minimal during the day. At night, however, the vibrations wake the whole colony, which causes the larvae commence their hunger signals and the workers to go forage for food to feed the larvae. Larval hunger signals produce no detectable changes in larval activity during the daytime. The workers, however, pay more attention and give more food to the cells that are in the vicinity of where the vibrations originated. At night, the larvae emulate each other's hunger signals and awake the whole nest.
The venom of V. orientalis was tested on Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, and Gram-negative bacteria, Escherichia coli and Klebsiella pneumoniae. Venom extract was shown to be effective in inhibiting the growth of Gram-positive bacteria. The venom is therefore regarded as a potential therapeutic agent.
Oriental hornets capture other insects such as grasshoppers, flies, honey bees, and vespids with which they feed the colony's brood. They will also collect other animal proteins for their young such as pieces of fresh or spoiled meat and fish. The adults eat carbohydrates such as nectar, honeydew, and fruits.
The Oriental hornet typically lives in nests that it digs underground. On the roof base of each comb cell one or more mineral granules of polycrystalline material is attached. A nest contains multiple combs in which the colony lives. While nests are most commonly found under ground, some paper nests are constructed in protective hollows such as inside hollow trees, in shipping containers, parked vehicles, and aircraft. To construct the paper nests, the workers strip the bark from twigs, tree branches, and shrubs to collect fiber.
