Trombiculidae

Tiny red bugs live in the grass.

These bugs are called chiggers. They are very small. They are hard to see.

Chiggers like damp places. They live near lakes and streams. They also like berry bushes. They are many in early summer.

Small chiggers feed on skin. They do not bite like a flea. They make a tiny hole. This makes the skin itchy. It can make red bumps.

After they eat, they drop down. They grow into bigger bugs. These adult bugs are not harmful. They eat plants and tiny insects.

These little bugs live all over the world. They like warm and wet lands. You might find them in a park.

Tiny red bugs live in the grass and forests.

In North America, people call them chiggers. In Britain, they are called harvest mites. These mites are very small. They are nearly microscopic. They often have a bright orange color.

Chiggers go through a life cycle. They start as eggs. Then they become larvae. These larvae are the only stage that feeds on animals. They can feed on rabbits, turtles, and even humans.

Chiggers do not bite like a flea. Instead, they make a tiny hole in the skin. They use digestive enzymes to break down skin cells. This creates a hardened tube called a stylostome.

The mite then eats the digested skin through this tube. This process causes red bumps and very itchy skin.

After they feed, the larvae drop to the ground. They grow into nymphs. Finally, they become adults. Adult mites have eight legs. They are not harmful to humans. They eat plants and small insects instead of skin.

Tiny mites called Trombiculidae live all around the world. In North America, many people know them as chiggers. In Britain, they are called harvest mites. They are also known by names like berry bugs or red bugs. These mites are very small and hard to see. They are nearly microscopic, measuring only 400 micrometers across. This is about 1/60 of an inch. Most of them have a bright chrome-orange color. They like to live in forests and grasslands. You might find them in damp areas near lakes or berry bushes. They also live in dry places like lawns and parks.

These mites go through a life cycle with four stages. They start as eggs and then become larvae. The larvae are the only stage that acts as a parasite. This means they feed on other living things like humans, rabbits, or even box turtles. To feed, the larva does not actually bite like a flea. Instead, it injects digestive enzymes into the skin. These enzymes break down skin cells to create a hardened tube called a stylostome. The larva then sucks up the digested skin through this tube. This process causes red bumps, hives, or a skin rash.

After the larva finishes feeding, it drops to the ground. It then grows into a nymph stage. This stage has three parts called the protonymph, deutonymph, and tritonymph. The deutonymph grows an extra pair of legs to have eight legs in total. Finally, the mite becomes an adult. Unlike the larvae, adult mites are not parasites. They are independent predators that eat small insects and plant material. They often live in the soil or in compost bins. Because they do not bite humans, the adults are harmless.

People have known about these mites for a very long time. Records of chiggers go back to sixth-century China. In 1758, a scientist named Carl Linnaeus described one species. Later, Henry Ellsworth Ewing described them as a separate family in 1944. In North America, the most common species is Trombicula alfreddugesi. It is found from the Atlantic coast to the Midwest and down to Mexico. In the UK, the most common type is Neotrombicula autumnalis. This species lives from Western Europe all the way to Eastern Asia.

If you are in a warm, humid place, you might encounter them. In the United States, they are most common in the South and Midwest. They are hard to find in deserts or high mountains. In the UK, they are common in August, so people call them aoûtat in French. In some parts of East Asia, a specific mite can carry a bacterium. This can cause a sickness called scrub typhus. This sickness can cause a fever or a headache. Most chigger bites in North America just cause itchy welts that heal on their own.

Trombiculidae is a family of tiny mites found all over the world. In North America, people often call them chiggers. In Britain, they are known as harvest mites. They also go by names like berry bugs, bush-mites, or red bugs. These mites are nearly microscopic. They measure about 400 micrometers, which is only 1/60 of an inch. Most of them have a bright chrome-orange color. While they are very small, they play a big role in their environments.

The life cycle of a trombiculid mite consists of four distinct stages. It begins as an egg, which is usually laid on a leaf or among plant roots. After about six days, a non-feeding prelarva emerges. This prelarva then grows into the larval stage. After feeding, the larva drops to the ground to become a nymph. The nymph stage includes three phases: the protonymph, the deutonymph, and the tritonymph. The protonymph is an inactive transitional stage. The deutonymph is active and grows an extra pair of legs to reach a total of eight. Finally, the mite matures into an adult.

Only the larval stage of the Trombiculidae is parasitic. These six-legged larvae seek out animal hosts to feed. They crawl onto animals like humans, rabbits, toads, box turtles, and quail. They even feed on some insects. The larvae do not actually bite or suck blood like many people assume. Instead, they inject digestive enzymes into the host's skin. These enzymes break down the skin cells. This process creates a hardened tube made of dead cells called a stylostome. The larva then uses this tube to suck up the digested tissue.

This feeding process can cause a condition called trombiculosis. This is the rash or infestation caused by the larvae. When the enzymes interact with the skin, they cause intense irritation. This often results in red papules, which are small pimple-like bumps. It can also cause hives, dermatitis, or skin lesions on sun-exposed areas. For humans, the intense itching often does not start until 24 to 48 hours after the larva has already detached. The red welts are not places where the mite laid eggs. Most of these itchy welts heal on their own within one to two weeks.

History shows that humans have been aware of these mites for centuries. References to chiggers go back as far as sixth-century China. In 1733, the first recognition of these mites in North America occurred. In 1758, the scientist Carl Linnaeus described a single species named Acarus batatas. Much of our modern scientific understanding came from studies conducted during and after World War II. In 1944, Henry Ellsworth Ewing first described Trombiculidae as an independent family. His work helped scientists organize the different subfamilies and genera within the group.

Different species of mites live in different parts of the world. In North America, the most familiar species is Trombicula alfreddugesi. It lives from the Atlantic coast to the Midwest and southward into Mexico. In the United Kingdom, the most common species is Neotrombicula autumnalis. This mite is found from Western Europe to Eastern Asia. In Australia, a species called Trombicula hirsti is known as the scrub-itch mite. These mites prefer warm and humid regions. They are less common in deserts, high mountains, or far northern areas.

While most chiggers are just a nuisance, some can be dangerous. In East Asia and the South Pacific, the species Leptotrombidium deliense is a serious pest. This mite can carry a bacterium called Orientia tsutsugamushi. This bacterium causes a disease known as scrub typhus. This illness can cause fever, headache, muscle pain, and gastrointestinal symptoms. Without medical treatment, scrub typhus can be fatal. This happens through transovarial transmission, where the bacteria are passed from parent to offspring. This connection shows how tiny organisms can impact large-scale human health.