Hornets have stingers that have been used to kill prey and secure nests. Since hornet venom contains a higher amount (5 percent) of acetylcholine, hornet stings are much more intense for people than traditional wasp stings. Individual hornets can sting repetitively; hornets do not die after stinging, with the exception of honey bees, because their stingers are quite finely barbed (only noticeable under high magnification) and can be easily removed, so when withdrawing, they are not pulled out of their bodies.
According to the hornet species, the severity of hornet stings differs; some produce only a normal bug sting, whereas others are among the most poisonous insects known. Single hornet stings, except often for allergic victims, are not in themselves lethal. Due to extremely toxic species-specific constituents of their venom, frequent stings by non-European hornets can be deadly.
The Asian giant hornet (V. mandarinia) stings one of the most poisonous bugs reported, and in Japan, they are believed to cause 30-50 annual human deaths. Hornet stings led to the deaths of 42 people in China between July and September 2013. The venom of the Asian giant hornet can trigger a reaction and multiple organ failure that leads to death, while dialysis can be used to eradicate the systemic toxins.
Many wasp lines, even those in the Vespidae, Crabronidae, Sphecidae, and Pompilidae families, attack and sting insects that they use as feed for their larvae; while Vespidae typically macerates their prey and directly feed the resultant bits to their brood, most predatory wasps paralyze their prey and lay eggs directly on the bodies, and they are eaten by the wasp larvae. In addition to gathering prey items to supply their young, many wasps are also voracious predators and will draw their prey's body fluids.
While vespid mandibles are ideal for grinding and tend to feed on the organism, they also simply macerate it into submission. It is difficult to determine the effect of the predation of wasps on economic pests. To provide their nests, the approximately 140 species of beewolf (Philanthinae) hunt bees, including honeybees; adults feed on nectar and pollen.
Social wasps are the models for many kinds of imitation with their strong stings and conspicuous alarm coloration. Batesian mimicry, where the imitation is harmless and is simply bluffing, and Müllerian mimicry, where the imitation is often distasteful, are two typical examples, and the mimicry may be considered mutual. Many species of hoverflies and the wasp beetle have Batesian mimics of wasps. In Müllerian mimicry, several species of wasps are involved, as are many species of bees.
With yellow markings on the front of the head and yellow banding around the abdomen, these bee-sized social wasps are black. With dark eyes, the face is predominantly yellow. The front wings of the Vespidae, when at rest, are folded lengthwise. The broad antennae are visible. These wasps are often mistaken for bees due to their scale, shape, and coloration. The nearest relatives of the Yellow Jackets, the hornets, closely match them but have a much bigger head.
As they are drawn to meat, fruit, and sweet drinks, Yellow Jackets are frequent visitors to picnics and parks in the summer. Yellow jackets are widespread around the world and are especially prolific in the southeastern United States. Yellow jackets are carnivorous, feeding on other bugs such as flies and mosquitoes mainly. They also feed on picnic food, flowers, vegetables, carrion, and nectar. Yellow jackets forage from their nest for around 1 mile.
Flower nectar (carbohydrates) and pollen (protein) are harvested from honey bees and are not attracted to meat. Yellow jackets are social insects living in groups of great size. To help sustain the colony, the queen, drones, and staff all have unique tasks. Hundreds of eggs are laid by the queen. The key role of the male drones is to be prepared to fertilize a queen who is receptive. Workers perform all the specific tasks required to operate the nest and sustain it.
Some insects are displaying yellow jacket imitation. In order to deter predation, the color imitations appear identical to the violent yellow jacket.