chiggers

Trombiculidae

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Subclass: Acari
Superorder: Acariformes
Order: Trombidiformes
Suborder: Prostigmata
Infraorder: Anystina
Superfamily: Trombidioidea
Family: Trombiculidae

Pronunciation

How to pronounce Trombiculidae: //trɒmˌbɪkjʊˈlɪdiː//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Summary

Trombiculidae, or chiggers, are a family of mites known for their larval stage that feeds on the skin of various animals, including humans, causing irritation and localized dermatitis. They are found in diverse habitats throughout the world and play both parasitic and predator roles depending on their life stage.

Physical Characteristics

Trombiculidae are nearly microscopic, measuring about 400 μm (1/60 of an inch) in size, and have a chrome-orange hue. Larvae are light red in color, approximately 170–210 μm in diameter, and covered in hairs. Adults have eight legs and resemble ticks.

Identification Tips

Look for small, reddish bumps on human skin after exposure to vegetation in summer. Larvae attach to areas of the skin where clothing is restrictive, such as belts or behind the knees.

Habitat

Trombiculidae thrive in forests, grasslands, berry bushes, orchards, and low, damp areas along lakes and streams. They are also found in dry places with low vegetation, such as lawns, golf courses, and parks.

Distribution

Trombiculid mites are found worldwide. In North America, they are prevalent in the Southeastern United States and the humid Midwest. In the UK, Neotrombicula autumnalis is common during summer and autumn.

Diet

In the larval stage, Trombiculidae feed on skin cells of various animals including humans, rabbits, toads, and quail. Adult mites are predators feeding on small arthropods and plant material.

Life Cycle

Trombiculidae go through a lifecycle consisting of egg, larva, nymph, and adult. The entire lifecycle can take between two to twelve months depending on environmental conditions.

Reproduction

Females lay three to eight eggs, typically on a leaf or plant roots. Eggs are dormant for about six days before hatching into non-feeding prelarvae.

Ecosystem Role

As larvae, they act as parasites on various animals; as adults, they are predators of other small arthropods and play a role in the decomposition of organic matter by feeding on plants.

Health Concerns

Larval bites can cause intense itching and irritation, leading to a condition known as trombiculosis. Some species can transmit diseases such as scrub typhus.

Collecting Methods

Use a sweep net in tall grass or vegetation during warm months.
Collecting soil samples from infested areas.

Preservation Methods

Preserve in ethanol or isopropanol for morphological studies.
Freeze specimens for genetic analysis.

Evolution

Trombiculidae was first described as an independent family in 1944, with references to similar organisms dating back to the sixth century.

Similar Taxa

Ticks (Ixodidae)
Fleas (Pulicidae)
Other mite families like Sarcoptidae.

Misconceptions

Chiggers do not burrow into the skin. The itching is caused by their saliva after they detach from the host, not due to them laying eggs under the skin.