Wasp

A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant. Wasps do not form a single natural group, as bees and ants evolved from wasp ancestors. Many wasps, like yellowjackets and hornets, live together in nests with a queen and workers, while most wasp species are solitary, with each female living and breeding on her own.

Wasps play important roles in nature. Some hunt or pollinate plants, while others lay eggs in the nests of other insects. Many solitary wasps help control pest insects, which is useful for growing crops like tomatoes. Wasps have been around since the Jurassic period and are found everywhere in the world except the polar regions.

The largest social wasp is the Asian giant hornet, while some of the smallest insects are tiny parasitic wasps. Wasps have also appeared in stories and literature, such as in Aristophanes' comedy The Wasps and in H. G. Wells' science fiction novel The Food of the Gods and How It Came to Earth.

Taxonomy and phylogeny

Wasps are a large group of insects found all over the world. They belong to a group called Apocrita, which includes many species but excludes ants and bees. Some wasps, like yellowjackets and hornets, are well-known types.

Wasps have been around for a very long time. Fossil records show that their ancestors appeared millions of years ago. Today, there are over a hundred thousand known species of wasps, and many more that have not yet been discovered. Some wasps are very small, almost too tiny to see, while others, like the Asian giant hornet, can be quite large. Many wasps play important roles in nature, such as helping to pollinate plants or controlling populations of other insects.

Sociality

Wasps can be social or solitary insects. Social wasps belong to the family Vespidae, mainly in the subfamilies Vespinae and Polistinae. These wasps often have black and yellow colors that warn other animals about their stings. They build nests using plant fibers, like wood pulp, and sometimes add mud or resin. Different species of social wasps build their nests in various places, such as trees, under leaves, or inside wall cavities.

Most wasps are solitary. After mating, a female wasp hunts for food and builds a nest just for her own babies. Some solitary wasps dig burrows in the ground, while others build nests from mud in protected spots. These wasps hunt other insects or spiders to feed their young, either leaving the food where it is or carrying it back to the nest.

Biology

Wasps, like all insects, have a hard outer shell called an exoskeleton that protects their three main body parts: the head, the middle section (which includes the thorax), and the back part of the body. They have a narrow waist called a petiole that connects the first and second parts of their abdomen. Female wasps often have a stinger used for defense and catching prey.

Wasps have large compound eyes and several simple eyes called ocelli. They use their mandibles for biting and cutting, and a tube-like proboscis for drinking nectar. Adult wasps mainly eat nectar, but they also hunt insects to feed their young. Some wasps build nests and stock them with prey for their larvae to eat. Social wasps may eat fruit, nectar, and even dead insects.

Ecology

As pollinators

While most wasps do not help plants grow, a few can carry pollen from flower to flower. Unlike bees, wasps usually don’t have soft hairs or special parts to hold pollen, so it doesn’t stick to them well. But some wasps can still move pollen and help certain plants grow. For example, pollen wasps collect nectar and pollen inside their bodies to pollinate flowers like Penstemon and plants in the water leaf family, Hydrophyllaceae. The fig wasps are special because they are the only pollinators for nearly 1000 types of figs. This helps both the wasps and the fig trees survive, making it a perfect partnership.

As parasitoids

Main article: Parasitoid wasp

Many wasps are called parasitoids. These wasps lay their eggs in or on other insects. The host insect stays alive until the wasp larvae grow up and leave. Some wasps can even paralyze their prey by stinging it. For example, the Ichneumonidae have very long stingers to reach their hosts hidden inside plants. Some of these wasps work with a special virus that weakens the host’s defenses.

As parasites

Further information: Kleptoparasitism and Cuckoo wasp

Some wasps lay their eggs in the nests of other wasps. These wasps use the care that the host wasp gives to its own young. For example, the paper wasp Polistes sulcifer lays eggs in the nests of other paper wasps, and its babies get fed by the host wasps.

As predators

Many wasps catch and sting other insects to feed their babies. Some wasps, like those in the families Vespidae, Crabronidae, Sphecidae, and Pompilidae, hunt bees and other insects. The beewolf wasps hunt bees to give to their larvae, while the adults drink nectar and pollen.

As models for mimics

Further information: Mimicry and Aposematism

Because wasps can sting and have bright warning colors, many other insects copy them. Some harmless insects, like hoverflies and the wasp beetle, look like wasps to scare away predators. This is called mimicry.

As prey

Some animals eat wasps. Birds like bee-eaters catch wasps in the air and remove the venom before eating them. The honey buzzard eats wasp larvae from nests, and roadrunners are the only predators of tarantula hawk wasps.

Relationship with humans

Social wasps can sometimes be pests when they build nests near buildings or become too numerous. People often get stung in late summer and early autumn when wasp colonies are looking for sugary foods. While stings are usually just painful, in rare cases they can cause serious health problems. Wasps are often seen as annoying or dangerous, partly because people don't know about their helpful roles in nature.

Some wasps are used to help control garden pests. Certain types of wasps lay their eggs inside harmful insects like whiteflies and aphids, which helps keep these pests from damaging plants. For example, the wasp Encarsia formosa is used in greenhouses to protect tomatoes, cucumbers, and other crops from whiteflies. These wasps are natural enemies of many garden pests and can be very effective at keeping their numbers down.