Hymenoptera

Bees, ants, and wasps are bugs.

There are many kinds of these bugs. Some are very small. Some are quite large.

Some bugs have a thin waist. These are called wasps, bees, and ants. Other bugs do not have a thin waist. These are called sawflies.

Many bugs use a stinger. A female bug can use it to protect herself. Some use it to catch food.

These bugs change as they grow. They start as tiny worms. Then they stay still in a shell. Finally, they grow into adults.

These bugs help plants grow. We must protect the places where they live.

Bees, ants, and wasps belong to a large group. We call this group Hymenoptera.

There are over 150,000 living species. They have been around since the Triassic period.

These insects have different body shapes. Some have no thin waist. We call these Symphyta. Sawflies are part of this group.

Their young look like caterpillars and eat leaves. Others have a narrow waist. We call these Apocrita. This group includes wasps, bees, and ants.

Most Hymenoptera go through holometabolism. This is a way of growing in four steps. First, they are wormlike larvae. Next, they enter a pupal stage. In this stage, they stay still. Finally, they become adults.

Many females have a special tool for laying eggs. This tool is an ovipositor. In some species, it becomes a stinger. They use the stinger to defend themselves. Some use it to catch food. This helps them survive.

Hymenoptera is a huge group of insects that includes bees, ants, and wasps.

There are over 150,000 living species known today. Scientists have also found more than 2,000 species that are now extinct. The name Hymenoptera comes from two Ancient Greek words. These words mean "membrane" and "wing."

This name describes their wings, which are often thin and clear. These insects are very important to our world. They help plants grow by moving pollen from flower to flower.

These insects grow in a special way called holometabolism. This is a type of complete metamorphosis. First, the insect starts as a wormlike larva.

Next, it enters a pupal stage where it stays inactive. Finally, it emerges as a fully grown adult. Many females have a tool called an ovipositor for laying eggs. They use this to reach places that are hard to get to. In many species, this tool has changed into a stinger.

Some use the stinger to protect themselves, while others use it to catch prey.

Scientists have studied how these insects changed over a very long time. Molecular analysis shows they are the earliest branching group of Holometabola. They first appeared during the Triassic period.

The oldest fossils we have belong to a family called Xyelidae. Later, during the Cretaceous period, social insects like ants and bees appeared. Experts like Alex Rasnitsyn and Michael S. Engel have studied their history. In 2023, a new study used ultra-conserved elements to map their family tree. This helped scientists understand how all these different species are related.

There are two main groups within Hymenoptera. The first group is called Symphyta, which includes sawflies. These insects do not have a thin waist between their body parts. Their larvae often look like caterpillars and eat leaves. The second group is called Apocrita, which includes wasps, bees, and ants. These insects have a very narrow waist called a petiole.

This narrow part connects the thorax to the abdomen. Most Apocrita larvae do not have legs or eyes. They often live in protected nests or inside other living things.

Many of these insects have very interesting ways of deciding if they are male or female. They use a system called haplodiploidy. In this system, fertilized eggs become females. Unfertilized eggs become males.

This means the female can control the sex of her babies. Some species, like the Cape honey bee, can even make female babies without any fertilization at all. This is called thelytoky. This unique way of life helps different species survive in their homes. It is one of the many ways these tiny creatures have mastered life on Earth.

Hymenoptera is a massive order of insects. It includes familiar groups like bees, ants, and wasps, as well as sawflies.

Scientists have described over 150,000 living species. They have also identified more than 2,000 extinct species. The name comes from Ancient Greek words meaning "membrane" and "wing."

This refers to their characteristic membranous wings. These insects are vital to the planet. They act as essential pollinators for many plants. However, they also play roles as predators and parasites.

Most hymenopterans undergo holometabolism. This is a process of complete metamorphosis. The insect begins as a wormlike larva.

It then enters a pupal stage where it remains inactive. Finally, it emerges as a fully developed adult. This lifecycle allows the young and adults to live in different ways. For example, larvae often eat different foods than the adults. This reduces competition between the different life stages.

Anatomy varies greatly across the order. Most species have well-developed mandibles for chewing.

Many have also evolved a long proboscis to drink nectar. Their wings usually consist of two pairs. A special structure called hamuli locks the hind wing to the fore wing. This coupling keeps the wings held together during flight. They also possess large compound eyes and three small simple eyes called ocelli. These eyes help them navigate their environments.

Females possess a specialized organ called an ovipositor. This tool is used for laying eggs in specific locations. In ancestral species, the ovipositor is blade-like for slicing plant tissue. In many other species, it is modified for piercing. In some groups, the ovipositor has become a stinger.

In these cases, eggs are laid from the base of the structure. The tip is used only to inject venom. This venom can immobilize prey or serve in defense.

Scientists divide Hymenoptera into two main suborders. The first is Symphyta, which contains sawflies and horntails. These insects lack a narrow waist. Their larvae are often eruciform, meaning they look like caterpillars. They usually have three pairs of true legs and several prolegs. The second suborder is Apocrita, which includes wasps, bees, and ants. These are defined by a narrow waist called a petiole.

Apocrita larvae typically lack legs, prolegs, and ocelli.

Evolutionary history shows that Hymenoptera is an ancient group. Molecular analysis suggests they are the earliest branching group of Holometabola. They originated during the Triassic period.

The oldest known fossils belong to the Xyelidae family. Social species, such as ants and bees, appeared later during the Cretaceous. Researchers like Alex Rasnitsyn and Michael S. Engel have studied this history. In 2023, a molecular study used ultra-conserved elements to confirm their family tree. This provided a robust phylogeny for the entire order.

Reproduction in this order is often unique due to haplodiploidy. This is a system where sex is determined by chromosome numbers. Fertilized eggs have two sets of chromosomes and become diploid females. Unfertilized eggs have only one set and become haploid males.

This allows the female to control the sex of her offspring. Some species even use thelytoky. This is a form of parthenogenesis where females create embryos without fertilization. This process helps maintain genetic diversity in certain colonies.

Many species are also parasitoids. These insects lay eggs in or on a host organism. Once the eggs hatch, the larvae consume the host. Some are even hyperparasitoids, which parasitize other parasitoids.

This complex web of life shows how interconnected these insects are. Because they are so important for pollination, habitat loss is a major threat. Losing these species could have huge ecological consequences for the world.