The genus Phidippus is the most recognziable genus of spiders in North America, due to their large size, fuzzy appearance, and conspicuous colors. Phidippus johnsoni are very common in Northern California and, during the mating season, both males and females acquire a bright red color on their abdomens. All Jumping spiders trail a drag line behind them when they jump, but it is usually difficult to see. In this photo, the lighting is just right for catching the silk.