Hydropsychidae

Common Name

Net-spinning Caddisflies

Overview

The Hydropsychidae family, commonly referred to as net-spinning caddisflies, includes a variety of freshwater insects known for constructing silk webs in streams and rivers. These webs are used to capture food particles carried by the water current.

Taxonomy

Key Characteristics

  • Antennae: Long and thread-like
  • Wings: Membranous and hairy, held roof-like over the body when at rest
  • Legs: Three pairs
  • Larvae: Aquatic, with well-developed anal prolegs and hooks

Life Cycle

  • Egg: Laid in water
  • Larva: Constructs silk nets to filter food; undergoes 5 to 7 instars
  • Pupa: Pupates in a silk cocoon within a sheltered environment
  • Adult: Emerges to mate and lay eggs; adults are generally short-lived, often only surviving long enough to reproduce

Behavior and Ecology

Hydropsychidae larvae construct silk nets to capture detritus, algae, and small invertebrates. They are essential in the aquatic food web, serving as prey for various fish and other predators. Their presence and abundance are often indicators of water quality and ecosystem health.

Notable Species

  • Hydropsyche angustipennis: Widespread across Europe, often feeding on fine particulate organic matter
  • Macrostemum zebratum: Known for its distinctive banded appearance and extensive silk net construction

Conservation

Hydropsychidae are generally not considered endangered, but their populations can be sensitive to water pollution and habitat degradation. Preservation of clean, flowing water bodies is crucial for their survival.

Significance to Humans

Net-spinning caddisflies are valuable biomonitors, used in assessing water quality and ecosystem health. Their presence in water bodies often indicates a low level of pollution.

Fun Facts

  • Hydropsychidae larvae often use their silk nets not just for feeding, but also as shelters.
  • Some species can produce up to several meters of silk thread per day.
  • Adult caddisflies are often attracted to lights at night, similar to moths.
  • Larvae can construct elaborate silk structures that help them withstand strong currents in their habitats.