The wolf spiders, family Lycosidae, are difficult to spot and even tougher to catch. Most lycosids live on the ground, where they use keen eyesight and quick speed to capture prey. Lycosa means wolf in Greek. Wolf spiders are one of the largest spider families.
Wolf spiders vary greatly in size. The smallest may measure only 3mm in body length, while most lycosids are larger, reaching up to 30 mm. Many species live in burrows in the ground, and most are nocturnal.
Most lycosids are brown, gray, black, pale orange or cream, often with stripes or speckles. The head region of the cephalothorax usually narrows. The legs, particularly the first two pairs, may be spiny to help the spiders hold their prey.
Spiders in the family Lycosidae can be identified by their eye arrangement. Wolf spiders have eight eyes, arranged in three rows. Four small eyes make up the lower row. In the center row, the wolf spider has two large, forward-facing eyes. The remaining two eyes in the upper row vary in size, but these face the sides of the head.
Lycosids feed primarily on insects. Some larger wolf spiders may also prey on small vertebrates.
While males rarely live beyond one year, female wolf spiders may live for several. Once she has mated, the female will lay a clutch of eggs and wrap them in a round, silk ball. She attaches the egg case to the underside of her abdomen, using her spinnerets to hold it in place. In fact, this behavior is characteristic of wolf spiders. Burrowing wolf spiders place their egg sacs in the tunnel by night, but bring them to the surface for warmth during the day. When the spiderlings hatch, they climb onto the mother's back until they have grown enough to venture out on their own.
Special Adaptations and Defenses:
Wolf spiders have keen senses, which they use to hunt, find mates, and protect themselves from predators. They can see quite well, and are also highly sensitive to vibrations which alert them to movements of other organisms. Wolf spiders rely on camouflage to hide them in the leaf litter where they roam.
Lycosids do use venom to subdue their prey. Some wolf spiders will flip onto their backs, using all eight legs like a basket to hold an insect catch, and then bite the prey with sharp fangs to render it immobile.
Range and Distribution:
Wolf spiders live nearly worldwide, just about any place where they can find insects for food. Lycosids are common in fields and meadows, but also inhabit mountains, deserts, rainforests, and wetlands. Arachnologists have described over 2,300 species, with about 200 kinds of wolf spiders living in North America.