Wolf spiders, belonging to the family Lycosidae, are common, ground-dwelling predators found in almost every habitat around the world. These arachnids are known for their robust build and eight-eyed appearance. Unlike many other spider species that rely on sticky silk to trap their meals, wolf spiders are active hunters that pursue and overpower their prey. This aggressive, solitary hunting behavior necessitates a specific diet and a unique method for both consuming food and maintaining hydration.
Active Hunting Methods
Wolf spiders are highly mobile predators that use speed and stealth rather than a stationary web to secure their food. They are often spotted wandering across the ground, or waiting in ambush near the entrance of a small burrow or beneath debris. Their name comes from the way some species run down and capture their prey, similar to a pursuit predator.
The success of their hunting relies heavily on their highly developed sensory organs. Wolf spiders possess excellent eyesight, especially the two large eyes in the middle row, which are adapted for motion detection in low-light conditions. These eyes contain a reflective layer, called the tapetum, that causes their eyes to shine brightly when a light source hits them at night. They are also extremely sensitive to vibrations in the substrate, using specialized hairs and slit sense organs on their legs to detect the movement of nearby insects. This combination of sight and vibration sense allows them to locate and track potential prey before pouncing.
Key Components of the Diet
The diet of the wolf spider is composed almost entirely of other arthropods that share their ground-level habitat. Their primary meals consist of various insects, including crickets, grasshoppers, beetles, ants, and flies that have landed on the ground. They also readily consume other spiders and soft-bodied invertebrates like worms, larvae, and insect nymphs.
Wolf spiders are generalist feeders, meaning they will attack and eat nearly any prey they can subdue. Larger species, such as those in the genus Hogna, can occasionally take on small vertebrates. Documented instances include the predation of tiny frogs, small lizards, and even hatchling snakes. However, the bulk of their nutrition comes from the constant supply of smaller, ground-dwelling insects and arthropods.
Water Intake and External Digestion
Wolf spiders, like all spiders, have a narrow gut that prevents them from consuming solid food, necessitating a process called extra-oral digestion. After capturing and biting their prey, the spider injects venom to immobilize the meal, followed by a cocktail of powerful digestive enzymes. These enzymes dissolve the internal tissues of the prey, turning the contents into a nutrient-rich liquid.
The spider then uses a muscular sucking stomach to draw this liquefied meal into its body, sometimes repeatedly pumping the fluid in and out to ensure maximum digestion. For larger prey, some wolf spiders use their chelicerae (mouthparts) to masticate the prey while the digestive fluids work, which helps to further break down the tissues. The spider continues this process until only the empty, hard exoskeleton of the prey remains. Hydration is maintained through the moisture extracted from this liquefied prey, and by directly drinking dew, standing water, or moisture from damp surfaces.