Waterscorpions

Nepidae

Classification

Pronunciation

How to pronounce Nepidae: //ˈnɛpɪdiː//

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

Images

Curicta pronotata MP AZ by Matthew Pintar. Used under a CC BY 4.0 license.
Curicta pronotata close up MP AZ by Matthew Pintar. Used under a CC BY 4.0 license.
Curicta scorpio MP TX 20221010 by Matthew Pintar. Used under a CC BY 4.0 license.
Curicta scorpio close up MP TX 20221010 by Matthew Pintar. Used under a CC BY 4.0 license.
Nepa apiculata by Even Dankowicz. Used under a CC BY 4.0 license.
Brown water scorpion by Greg Hume. Used under a CC BY-SA 4.0 license.

Summary

Nepidae, or waterscorpions, are exclusively aquatic insects characterized by their resemblance to scorpions and adapted for life in freshwater environments. They comprise two subfamilies and are distributed worldwide, with the most diversity in warmer regions. Their diet mainly includes aquatic invertebrates, and they have unique adaptations for respiration and predation.

Physical Characteristics

Nepidae are brown insects with a broad and flat body (Nepinae) or a long and thin body (Ranatrinae). Some species have a bright red abdomen visible when wings are open. Size varies predominantly between 15-46 mm (body length) + 16-44 mm (breathing tube).

Identification Tips

Distinct raptorial forelegs for grasping prey; elongated breathing siphon that resembles a tail; superficial resemblance to scorpions.

Habitat

Stagnant or slow-moving freshwater habitats such as ponds, marshes, canals, streams, and occasionally hypersaline lakes and brackish lagoons.

Distribution

Found on all continents except Antarctica; widespread in warmer regions.

Diet

Primarily feed on aquatic invertebrates such as other insects, small fish, or tadpoles.

Life Cycle

Immature forms have underdeveloped siphons and breathe through abdominal spiracles; eggs are laid above waterline in mud or on vegetation, supplied with air by filamentous processes.

Reproduction

Eggs are laid above the waterline in mud or decomposing vegetation.

Ecosystem Role

Predators of aquatic invertebrates, contributing to the control of pest populations.

Health Concerns

While they have a painful bite, it is less harmful than a true scorpion's sting.

Evolution

Araripenepa from the Early Cretaceous is the oldest known member of the family, highlighting ancient lineages of the Nepidae.

Similar Taxa

Misconceptions

Often mistaken for true scorpions due to their appearance; do not sting with their tail.

Tags

  • Nepidae
  • Waterscorpions
  • Aquatic Insects
  • Heteroptera
  • Hemiptera