The Sierra Dome Spider (Neriene Litigiosa) is a member of the Linyphiidae family. They are small spiders that do not exceed 8 mm in body length. In spite of this, they are the largest Linyphiidae in North America. They are sheet weaver spiders. They build webs that have a dome shape in the center, the web itself is placed horizontally in its layout. if prey gets tangled in the dome, the spider will attack it from below the dome and bite them through the web. This protects the female from possible injury during feeding.
Males will do battle (ritualized) to try and impress the females, they will sometimes live on the web with the females. They are attracted to the web by pheromones placed there by the female. If they need to, the female can spray pheromones into the air to temp males from further away. Once a male has mated with the female, he will often hang out to discourage other males from mating, but if he leaves, she will mate again. A male will sometimes remove the pheromone-scented silk after mating with the female to prevent other males from being attracted.
These spiders feed on midges, flies, and other small insects that get trapped in their web. Look for them in open areas and along the forest edge, you will often see them in home gardens in our region. The adults are active from spring up to the first frost of the year.
If you look up the name Neriene in Roman mythology, you will find it is the name of the wife of Mars, the god of war. I would suspect this name was chosen in reference to the male’s willingness to do battle, if only in its ritualized form. They are quite fascinating to observe in the wild.