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Nicodamidae

Web builder, using small sheet webs near the ground.

Nicodamidae is a family of araneomorph spiders native to Australia and Papua New Guinea. These small to medium-sized spiders are often referred to as "red and black spiders" due to their distinctive coloration. They construct small sheet webs near the ground in eucalypt forests.

Key Facts

  • Found in Australia and Papua New Guinea.
  • Characterized by a red cephalothorax and legs with a black abdomen.
  • Construct small sheet webs near the ground.
  • Inhabit eucalypt forests.
  • Comprise seven genera and twenty-seven species.
  • Sometimes called "red and black spiders".
Nicodamidae
Scientific Name
Nicodamidae
Common Names

Red and Black Spiders

Family
Nicodamidae
Habitat
Near the ground of eucalypt forests.
Geographic Distribution

Australia, Papua New Guinea

Size Description
Small to medium-sized spiders.
Coloration
In most cases, the cephalothorax and legs are uniformly red and the abdomen is black.
Distinguishing Features

Uniformly Red Cephalothorax and Legs., Black Abdomen.

Diet
Insects and other small invertebrates caught in their webs.
Image Url
https://upload.wikimedia.org/wikipedia/commons/5/58/Nicodamus_idae.jpg
Behavior Characteristics

Build Small Sheet Webs Near the Ground.

About Nicodamidae

The Nicodamidae family encompasses a group of araneomorph spiders found in Australia and Papua New Guinea. These arachnids are recognized for their striking "red and black" coloration, a characteristic that often leads to their common name. They are typically small to medium-sized and are known for constructing their small sheet webs near the ground, particularly within eucalypt forests.

Taxonomy and Classification

The family Nicodamidae was formally established by Eugène Simon in 1897. A significant review of the family was conducted by Mark Harvey in 1995, which involved dividing the family and erecting new genera based on morphological cladistic analysis. While Pekka T. Lehtinen had previously suggested that a related group, Megadictynidae, should be a separate family, this was not initially accepted. However, molecular phylogenetic analysis in 2017 led to the re-establishment of Megadictynidae, which in turn reduced the scope of Nicodamidae to its current seven genera.

Genera and Species

As of early 2026, the Nicodamidae family comprises seven genera and a total of twenty-seven species. These species share common traits in their habitat and morphology, contributing to their classification within this family.

Habitat and Behavior

Nicodamidae spiders are primarily found near the ground level within eucalypt forests. Their hunting strategy involves building small sheet webs, which they utilize to capture their prey. The consistent placement of these webs near the ground is a notable aspect of their behavior.

Source: Wikipedia ↗

Frequently Asked Questions

Where are Nicodamidae spiders found?

Nicodamidae spiders are exclusively found in Australia and Papua New Guinea. They typically inhabit the ground level of eucalypt forests within these regions.

What do Nicodamidae spiders look like?

These spiders are often recognized by their "red and black" coloration. Generally, their cephalothorax and legs are a uniform red, while their abdomen is black.

How do Nicodamidae spiders catch their prey?

Nicodamidae spiders build small sheet webs. These webs are typically situated near the ground, serving as their primary method for capturing prey.

What is the size of Nicodamidae spiders?

Nicodamidae spiders are described as small to medium-sized. Specific measurements are not detailed, but their general classification indicates they are not exceptionally large arachnids.

How many species are in the Nicodamidae family?

As of January 2026, the Nicodamidae family consists of twenty-seven species organized into seven distinct genera.