
A hornet's sting is painful to humans, but the sting toxicity varies greatly by hornet species. Some deliver just a typical insect sting, while others are among the most venomous known insects.[1] Allergic reactions, fatal in severe cases, can occur; an individual suffering from anaphylactic shock may die unless treated immediately via epinephrine ("adrenaline") injection using a device such as an EpiPen, with prompt followup treatment in a hospital.
European hornet sting
in itself is not fatal except sometimes to allergic victims.[1]
multiple stings (several hundred) may be fatal due to the amount of venom (similar to wasps and bees).[citation needed]
is less toxic than a bee sting.[citation needed]
Non-European hornet sting
in itself is not fatal except sometimes to allergic victims.[1]
multiple stings (an entire nest) can be fatal due to highly toxic species-specific additions in the venom.[2]
is more toxic than a wasp or bee sting
from the Asian giant hornet (Vespa mandarinia japonica) is the most venomous known (per sting).[1]
All hornet stings
are an allergen for people with an allergy to wasp venom.
those allergic to wasp venom are not necessarily allergic to bee venom as they contain different chemicals.
contain less volume of venom than a bee sting.[citation needed]
are primarily for killing insect prey.[citation needed]
are more painful than a typical wasp's due to a large amount (5%) of acetylcholine.[3] See Schmidt Sting Pain Index.[4]
As in all stinging wasps, hornets can sting multiple times; they do not die after stinging a human as is typical for a worker honey bee, as a hornet's sting is not barbed (the honey bee stinger has evolved for defending the nest against vertebrates/mammals). They can also bite and sting at the same time.
[edit] Alarm escalation
Hornets, like many social wasps, can mobilize the entire nest to sting in defense, which is highly dangerous to humans. The hornet alarm pheromone is used to raise alarm of nest attack and to identify prey, such as bees.[5] It is not advisable to kill a hornet anywhere near a nest, as the distress signal can trigger the entire nest to attack. Materials that come in contact with pheromone, such as clothes, skin, dead prey, or hornets, must be removed from the vicinity of the hornets nest. Perfumes and other volatile chemicals can be falsely identified as pheromone by the hornets and trigger an attack.
[edit] Prey
Hornets and yellow jackets prey on many insects that are considered to be pests, so they are actually beneficial. They do also prey on bees, but unlike honey bees, hornet and yellow jacket colonies die out every winter.
[edit] Hornets and other Vespidae
European hornet with the remnants of a honey bee.While taxonomically well-defined, there may be some ambiguity about the differences between hornets and other wasps of the family Vespidae, specifically the yellow jackets, which are members of the same subfamily. Yellow jackets are generally smaller than hornets and are bright yellow and black, whereas hornets may be darker in color - see wasp and bee characteristics.
Another major difference between yellow jackets and hornets is each of their food choices and aggression towards humans. In autumn, yellow jackets may be attracted to human foods and food wastes, increasing potentially aggressive contact between yellow jackets and humans. Hornets, on the other hand, tend to stick to live insects.
Some other large wasps are sometimes referred to as hornets, most notably the bald-faced hornet (Dolichovespula maculata) found in North America. It is set apart by its black and ivory coloration. The name "hornet" is used for this and related species primarily because of their habit of making aerial nests (similar to the true hornets) rather than subterranean nests. Another example is the Australian hornet (Abispa ephippium), which is actually a species of potter wasp.