Sac Spiders

Clubionidae

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Clubionidae

Pronunciation

How to pronounce Clubionidae: /kluːˈbaɪ.ə.nɪˌdiː/

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

Images

Summary

The family Clubionidae, known as sac spiders, includes the genera Clubiona and Elaver in North America. These spiders are characterized by their eight eyes, conical spinnerets, and their habit of constructing silk retreats. Historically, this family had a confusing classification, previously incorporating various unrelated taxa.

Physical Characteristics

Eight eyes arranged in two rows and conical anterior spinnerets that touch.

Identification Tips

Look for wandering predators that build silken retreats or sacs, usually found on plant terminals, between leaves, under bark, or under rocks.

Habitat

Found in various habitats, including forests and grasslands, often in leaf litter or on vegetation.

Distribution

Widespread in the USA and Canada (Clubiona); distributed in Eastern USA and extreme southeastern Canada west to Montana and Arizona (Elaver).

Diet

Primarily predatory, feeding on small insects and other arthropods.

Ecosystem Role

Play a role in controlling insect populations as predators.

Evolution

Once a catch-all taxon, Clubionidae has a complex taxonomic history with many genera transferred to other families.

Similar Taxa

Misconceptions

The term 'sac spider' can refer to members of other families, not just Clubionidae.