Epiocheirata

Pronunciation

How to pronounce Epiocheirata: /ˌɛpiəˈkaɪrətə/

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Summary

Pseudoscorpions, or false scorpions, are small arachnids belonging to the order Pseudoscorpiones. They are mostly beneficial as they prey on various household pests, and play a significant ecological role in controlling insect populations. With over 3,300 species, they inhabit a variety of environments worldwide but are often overlooked due to their size. Their biology, lifecycle, and behavior underline their importance in both natural ecosystems and human habitats.

Physical Characteristics

Pseudoscorpions have a flat, pear-shaped body and pincer-like pedipalps resembling true scorpions. They typically range in size from 2 to 8 mm (0.08 to 0.31 in) in length, with the largest known species, Garypus titanius, reaching up to 12 mm (0.5 in). They have eight legs and two very long pedipalps with palpal chelae, a mobile 'finger' and an immobile 'hand'. The abdomen consists of twelve segments covered by sclerotized plates and is short and rounded at the rear.

Identification Tips

Pseudoscorpions can be identified by their scorpion-like appearance, particularly their prominent pincers and eight legs. They usually range in size from 2 to 8 mm, and may have two, four, or no eyes. Common in dusty areas, such as libraries, they may be mistaken for ticks or small spiders due to their size and shape.

Habitat

Pseudoscorpions are found in a variety of environments including soil, leaf litter, under tree bark, and in caves. They inhabit diverse ecosystems from tropical to temperate regions, including urban areas where they may be found indoors.

Distribution

There are over 3,300 species of pseudoscorpions recorded globally, with the highest diversity found in tropical and subtropical regions. They have been located in various environments, including the Rocky Mountains in the USA, the Jenolan Caves in Australia, and the Canary Islands where many endemic species exist.

Diet

Pseudoscorpions are predatory and feed on small insects and arthropods, such as clothes moth larvae, carpet beetle larvae, booklice, ants, mites, and small flies. They immobilize their prey using venom and digest it with exuded fluids.

Life Cycle

After mating, females carry fertilized eggs in a brood pouch and can hatch between 2 and 50 young per brood. Young undergo three molts (protonymph, deutonymph, tritonymph) and are nourished with a milk-like substance produced by the mother. They live 2–3 years as adults, overwintering in silken cocoons.

Reproduction

Males produce a spermatophore that the female collects from the substrate. Some species possess a spermatheca for sperm storage, allowing fertilization to occur later. They can have multiple broods per year, and fertilized eggs are kept in a brood pouch.

Ecosystem Role

Pseudoscorpions play an important role in controlling pest populations in various ecosystems by preying on their larvae and small insects.

Economic Impact

Due to their predatory habits, pseudoscorpions are beneficial for natural pest control, especially against pests like booklice in human habitats, making them economically valuable in urban settings.

Cultural Significance

Pseudoscorpions have been noted in historical observations, including descriptions by Aristotle and references in literature, indicating their presence and significance in human environments earlier in history.

Collecting Methods

• Hand collection
• Pitfall traps
• Sweep netting

Preservation Methods

• Alcohol preservation
• Drying and pinning
• Embedding in resin

Evolution

The oldest known fossil pseudoscorpion, Dracochela deprehendor, dates back to the mid-Devonian, indicating that pseudoscorpions have existed for approximately 383 million years, showing little morphological change since their early appearance.

Similar Taxa

• True scorpions (Scorpiones)
• Spiders (Araneae)
• Ticks (Acari)

Misconceptions

Pseudoscorpions are often confused with true scorpions or ticks due to their small size and similar body shape; however, they do not possess stingers and are not harmful to humans.

Tags

• Epiocheirata
• Pseudoscorpions
• Arachnids
• Ecology
• Biodiversity