Meet Walckenaer’s Studded Triangular Spider And The Rest Of Its Triangular Family

The spider species Walckenaer's studded triangular spider (Arkys walckenaeri) is found in Australia and belongs to the orb weaving family Arkyinae, also known as the triangular spiders. This species is an ambush hunter with curved forelegs and the classic triangular abdomen. The name Walckenaer comes from the French scientist and civil servant Charles Athanase Walckenaer. 

Triangular spiders typically have the very distinctive triangular abdomens, which can also be heart- or leaf-shaped to better blend in with their surroundings. Typically male triangular spiders are slightly smaller than the females, which measure around 4-7 millimeters (0.15-0.2 inches) in length. The spiders have some regional differences, with spiders in the Queensland area having white sigilla on an orange or red triangle. This differs from those in the west, south, and Tasmania, which are pale yellow with less obvious markings. 

Some species in the genus Arkys are not triangular at all and instead resemble bird droppings as further camouflage. These spiders are found in a range of habitats, from eucalyptus forests to woodlands and even people’s backyards. 

Unlike other species, triangular spiders do not use their webs for prey; instead, they ambush small insects and other invertebrates from the underside of leaves. Their silk is used to make egg sacs, which can be pinkish or orange and are usually laid in the late summer. Little is known about the species' courtship, but it is thought to include intricate movements and the production of pheromones. Triangular spiders are said to be harmless to humans. 

Elsewhere in the spider world, parasites are driving spiders to water before their deaths and, in a world first, a CRISPR gene-edited spider can now produce glowing red silk.