The Horned Spiders in Idaho

Types

• Orb weaver spiders are found in all parts of Idaho and are classified in the Araneidae family. Cat-faced spiders and garden spiders are common species of orb weavers in Idaho. Cat-faced spiders are about the size of an olive and have pointed horns on the abdomen that resembles a cat's face. They have red bodies with orange, white and black abdomens. Their red, brown and beige legs are covered with spikes. Garden spiders grown to about 2 inches in width and are black with yellow and silver. Their abdomens have light-yellow horned bumps. These spiders rarely bite and may cause some localized pain.

Habitat

• Orb weavers are web spinning spiders that primarily live outside. Cat-faced spiders often spin their webs and live under the eaves of houses, while garden spiders live in the bushes and in tall reeds. Orb weavers are generally found near homes and gardens. Their webs are made up of concentric rings that resembles a bull's eye. These spiders are typically nocturnal, or active at night, when they hunt, repair their webs and rebuild them at dusk or dawn.

Food

• All orb weavers spin their webs to trap prey and are carnivorous. Cat-faced spiders spin webs near lights to catch moths and other night-flying insects at nighttime. Garden spiders wrap their prey up like mummies and use their fangs to inject venom. Spiders only ingest liquids, and they inject their prey with enzymes that break down their body tissues. After this happens, the spider sucks the liquid as its food.

Reproduction

• Orb weavers lay eggs to reproduce. After the eggs hatch, they are called spiderlings, which look like the smaller form of adult spiders. Through molting, which is when they shed their exterior exoskeleton skins, they grow larger into adults. Once they reach adulthood, they no longer molt or grow. Female orb weavers protect their eggs by spinning silk coats around their eggs and then attaching them to their abdomens. These egg cases or sacs may contain hundreds of eggs. Young spiders use a method called ballooning to travel to different habitats. They climb onto a tall plant and spin a silk line to capture the wind that takes them to a random location.