Wolf spiders and grass spiders are two common types of spiders found throughout North America. At a glance, they appear somewhat similar – both are hairy, brown spiders with markings on their bodies. However, there are some key differences between these two species when it comes to their appearance, behavior, habitat and more.
Appearance: Markings and Eyes Set Them Apart
One of the most noticeable differences between wolf spiders and grass spiders is their markings. Wolf spiders have very bold black stripes or bars on the top of their abdomens. These markings are thicker and darker than those found on grass spiders. Grass spiders have thinner lighter lines or bars on their abdomens. The overall color of grass spiders also tends to be lighter than wolf spiders.
Their eyes are also telling. Wolf spiders have three rows of eyes – four small eyes on the bottom two big eyes in the middle and two smaller eyes on top. This allows them to have excellent eyesight for hunting. Grass spiders have a different eye arrangement – two larger eyes on the bottom, four eyes in the middle and two up top. Their vision is not considered as good as the wolf spider’s.
Hunting vs Web-Spinning Behaviors
Wolf spiders and grass spiders have very different techniques when it comes to catching prey. Wolf spiders are active hunters, meaning they don’t spin webs. Instead they rely on their excellent eyesight and speed to chase down prey once spotted. Some wolf spiders will even fish for aquatic insects and small fish near water.
On the other hand, grass spiders use webs to trap insects They construct funnel-shaped webs with a tunnel retreat, usually low in vegetation The grass spider waits in this hideout for prey to land in the web, then rushes out to subdue it. Wolf spiders do not spin these types of webs.
Habitats Vary
While wolf spiders and grass spiders do overlap in certain habitats like gardens, overall they tend to occupy different areas.
Wolf spiders are found just about everywhere – forests, deserts, mountains, meadows, suburban lawns, inside homes and more. They are not picky and their hunting lifestyle allows them to thrive in many environments.
Grass spiders, as their name implies, prefer to stick close to the ground in meadows, prairies and other grassy areas. They are far less likely to venture into arid desert environments. Being web dwellers, they rely on having vegetation to anchor their funnel webs.
Reproduction and Offspring Care
The mating rituals and care of offspring differ quite a bit between wolf spiders and grass spiders as well.
To mate, male wolf spiders will tap out a courting “song” by drumming on dry leaves. If the female accepts, she allows him to deposit a sperm packet before quickly taking off – otherwise she might eat him! The female then produces an egg sac that she attaches to her spinnerets and carries with her everywhere until the eggs hatch. Once they emerge, the spiderlings will ride around on mom’s back for up to a week before dispersing.
With grass spiders, reproduction involves the male leaving a sperm packet on the female’s web while she hides in her tunnel. If she emerges to collect it, mating is successful. She will also produce an egg sac, but unlike wolf spiders she does not carry it with her. The young emerge without ever interacting with the mother.
Venom and Bites
The good news is that neither wolf spiders or grass spiders are considered dangerous to humans. Their venom is designed to subdue small invertebrate prey, not large animals.
That said, a bite from a wolf spider may be more likely to break skin and cause mild pain or itching, as they have larger fangs. Grass spider fangs are smaller and less likely to penetrate skin deeply.
Only around 200 spider species in the world are known to have venom capable of causing serious harm to people. Rest assured that both the wolf spider and grass spider fall into the majority of spiders with mostly harmless venom.
Keeping Them Out of Your Home
Many people prefer not to have spiders like these taking up residence in their houses. Here are some tips to discourage them:
- Trim bushes and vegetation touching the home’s exterior
- Keep lawn areas clear of dense ground cover and mow regularly
- Eliminate wood piles, leaf litter and other debris they can hide in
- Seal any cracks, crevices or openings they could use to enter
- Use outdoor lighting selectively at night when needed
- Remove food sources like unattended pet bowls or open compost piles
While wolf spiders and grass spiders may look similar at first glance, they have key differences when it comes to their markings, eyes, behavior, habitats and reproduction. Both play an important role controlling insect populations outdoors. And neither pose a major threat to humans if left alone. Learning to identify and understand local spider species can help you take proper precautions while appreciating their benefit to ecosystems.
Spiders of Medical Significance
Size: Adult female is about 1/2 inch long. Color: Adult females are glossy black with a variable number of red markings on the top and bottom of abdomen. Adults males are similar, but with a few white markings. Juveniles are highly variable. Features: Abdomen is nearly spherical on adult females and juveniles. Male is slimmer with longer legs (pictured here). Notes: Bites are very serious and require immediate medical attention, but the spider is timid and unlikely to bite unless handled. Black widows are common all over Kentucky. They tend to occur in concealed outdoor locations: piles of rocks, piles of firewood, and dark corners of garages and out-buildings. Females are common; males are very rarely encountered.
Size: About the size of a U.S. quarter, with legs outstretched. Color: Tan to dark brown, abdomen and legs are uniformly colored with no stripes, bands, or mottling. The legs are long and thin and lack conspicuous spines. Features: Dark violin-shaped mark on back, with the neck of the violin pointing toward the rear (abdomen) of the spider. This feature is consistent in adult brown recluses, but can be hard to see and is less obvious in younger spiders. Also, brown recluses only have six eyes: most Kentucky spiders have eight. Notes: Bites are very serious and require immediate medical attention, but brown recluses are timid and unlikely to bite unless handled. These spiders are more common in Western KY, less common in Central and Southeastern KY. They tend to occur in hidden locations indoors and outdoors: piles of cardboard or paper, stacks of cut wood, and wall-voids of buildings.
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ENTFACT SUPPLEMENT: Urban Spider Chart
The majority of Kentuckys spiders are harmless to humans, even when they enter our living environments. This chart is designed to help with quick identification of spiders that are commonly encountered in homes, buildings, yards, and other urban environments.
Wolf Spider v.s. Grass Spider: Not what I’d anticipated..
FAQ
Is a grass spider poisonous?
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Venomous, not poisonous:Grass spiders, like all spiders, have venom, which they use to subdue their prey. However, they are not considered poisonous, meaning their venom is not transmitted through skin contact or ingestion.
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Bites are rare and usually minor:Grass spiders are shy and not aggressive, so they rarely bite humans unless they feel threatened. Their bites, when they do occur, are usually small and cause localized pain, swelling, redness, and itching.
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Rarely cause serious harm:While some people may be more sensitive to spider venom, severe reactions are very rare. If a bite causes significant symptoms or if you are unsure about the spider, it’s always best to seek medical attention.
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PestWorld.org says that if left untreated, the venom from a grass spider bite can sometimes cause necrotic skin lesions and bacterial infections, but this is rare.
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Beneficial role in the ecosystem:Grass spiders play a beneficial role in controlling insect populations in gardens and grassy areas.
How do you identify a wolf spider?
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Appearance:
- Color: Wolf spiders are typically brown, gray, black, or tan, often with dark markings or stripes.
- Size: They can range in size, with some species being relatively small and others growing quite large, with some reaching over an inch in body length.
- Eyes: The most distinctive feature is their eye arrangement: four small eyes in a row, two larger eyes above, and two medium-sized eyes on top.
- Body: They have robust and hairy bodies.
- Legs: Wolf spiders have long, thin legs.
- Color: Wolf spiders are typically brown, gray, black, or tan, often with dark markings or stripes.
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Behavior:
- Hunting: They are known for their hunting behavior, as they stalk prey rather than building webs.
- Speed: They are also known for being incredibly fast, reaching upwards of 10mph at full speed.
- Jumping: They are also exceptionally good at jumping, capable of jumping 10 times their own body length.
- Hunting: They are known for their hunting behavior, as they stalk prey rather than building webs.
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Distinguishing from other spiders:
- Brown Recluse: While wolf spiders can resemble brown recluse spiders, the brown recluse has a distinctive violin-shaped marking on its back, which wolf spiders lack.
- Grass Spiders: Grass spiders have a spinneret at the end of their abdomen, which is used for web-making, while wolf spiders do not.
- Brown Recluse: While wolf spiders can resemble brown recluse spiders, the brown recluse has a distinctive violin-shaped marking on its back, which wolf spiders lack.
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- Wolf spiders are not aggressive and will not bite unless frightened or provoked.
- Although their bite is not deadly, it can be very painful.
- Wolf spiders typically only bite humans if they are handled or touched.
- Wolf spiders are not aggressive and will not bite unless frightened or provoked.
Are wolf spiders bad in your house?
- Not Venomous to Humans: Wolf spider venom is not dangerous to humans, and bites are typically mild, causing only temporary pain and swelling.
- Rarely Bite Humans: Wolf spiders are not aggressive and rarely bite humans unless they feel threatened or are provoked.
- Not a Threat to Property: They don’t damage homes or chew through wires like other pests.
- Solitary Creatures: Wolf spiders are solitary hunters and are unlikely to be found in large numbers inside a home.
- They are beneficial: They eat other insects, including ants, fleas, earwigs, and bed bugs.
Why are there so many wolf spiders in my yard?
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Food Source:Wolf spiders are predatory spiders, meaning they hunt and eat insects. If your yard has a lot of insects, it will attract wolf spiders as a food source.
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Hiding Places:Wolf spiders often hide in leaf litter, mulch, tall grass, and other debris. Keeping your yard tidy and free of clutter will make it less appealing to them.
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Habitat:Wolf spiders are found in various environments, including forests, gardens, grasslands, and marshes, so they are adaptable to different habitats.
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Moisture:Wolf spiders thrive in moist environments, so reducing moisture is crucial.
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Other Factors:Wolf spiders may also be attracted to areas with cracks, crevices, or small openings around doors and windows, which they can use to enter homes.
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Wolf spider bites are generally not dangerous to humans, though they may cause some pain and swelling.
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Prevention:To reduce the number of wolf spiders in your yard, you can:
- Clean up debris: Regularly rake leaves, remove mulch, and mow tall grass.
- Minimize clutter: Keep your yard tidy and free of clutter, such as old boxes, piles of clothing, and newspapers.
- Seal entry points: Seal any cracks or openings around doors and windows to prevent wolf spiders from entering your home.
- Consider professional help: If you have a serious wolf spider problem, you may want to contact a pest control professional.
- Clean up debris: Regularly rake leaves, remove mulch, and mow tall grass.