What Do Crab Spiders Eat: A Closer Look at Their Diet

Crab spiders are fascinating creatures that belong to the Thomisidae family. They get their name from their crab-like appearance and movement. Known for their diverse range of species, these spiders can be found in various habitats, from gardens to forests.

As predators, crab spiders primarily feed on insects. They do not build webs to catch prey like other spider species. Instead, they use their exceptional camouflage abilities to ambush and capture victims. Some species are even known to hunt in flowers, patiently waiting for their next meal.

Adapting to the environment they inhabit, crab spiders have developed impressive hunting skills. You might observe them stalking their unsuspecting prey or strategically positioning themselves on plants to increase the chances of seizing a tasty insect. This intriguing feeding behavior is just one reason why many find crab spiders to be such fascinating creatures.

Crab Spider Basics

As an arachnid enthusiast, you might be curious about crab spiders. These fascinating creatures belong to the Thomisidae family and exhibit unique features and behaviors. Let’s explore some of their basic characteristics.

Crab spiders earn their name from their distinct appearance, which is reminiscent of a crab. Their flat bodies are equipped with eight eyes and spindly legs that extend sideways from their body, allowing them to walk in various directions.

You may notice these spiders in a wide range of sizes and colors. Typically, they have a body length spanning between 2-11 mm. Their color can range from white to yellow, green, and even brown. Some species, such as the Goldenrod Crab Spider, are able to change color to blend with their surroundings, usually between yellow and white.

An interesting aspect of crab spiders is the difference in size between their front and back legs. The front legs are considerably longer than the back legs, which plays a crucial role in their hunting strategy.

Crab spiders don’t weave webs like other spiders. Instead, they prefer to ambush their prey. Their longer front legs are perfect for grasping unsuspecting insects that visit flowers, while their shorter back legs provide stability.

In summary, crab spiders are a captivating arachnid species known for their crab-like appearance, diverse size and color, and unique hunting techniques. As a spider enthusiast, you can appreciate these intriguing creatures and their place in the natural world.

Diet and Hunting Techniques

Crab spiders are generalist predators, which means they feed on a wide variety of arthropods. Their diet primarily consists of insects such as ants, wasps, and other small creatures. Besides insects, they also consume pollen and even nectar. To ensure a diverse diet, growing a range of flowering plants can help.

They are masters of ambush, using the element of surprise to catch their prey. Crab spiders rely on their camouflage to blend in with their surroundings as they patiently wait for an unsuspecting meal to pass by. Once the target is within range, they rapidly pounce and use their strong front legs to capture and immobilize the prey.

You may observe crab spiders adopting different hunting techniques depending on their environment:

  • On flowers, they hide and match the color of the petals.
  • On the ground, they blend in with leaf litter or grass.

These adaptable hunters adjust their hunting strategy based on the available food sources. They may change their color to blend in better with their surroundings, like the Goldenrod Crab Spider, which can switch between yellow and white to match the flower they are on.

Remember, crab spiders don’t build webs to catch prey. Instead, they rely on their expert hunting skills and agile movements to sneak up on and capture a meal. So, when you’re admiring your garden, keep an eye out for these fascinating little ambush predators.

Habitats and Camouflage

Crab spiders are mainly found in diverse habitats like flowers, plants, leaf litter, and bark. Their habitat preference is influenced by their exceptional camouflage abilities.

These spiders exhibit brilliant coloration, which enables them to blend in effortlessly with their surroundings. For instance:

  • In flower beds, they match the hue of the petals, waiting for potential prey.
  • On tree bark or leaf litter, they assume earthy shades to stay inconspicuous.

Their camouflage technique plays a crucial role in both their hunting strategy and protection against predators. Learning about their habitats and camouflage techniques will give you a better understanding of these fascinating creatures. So, when exploring nature, keep an eye out and appreciate these skilled masters of disguise.

Thomisidae Family and Genera

The Thomisidae family, also known as crab spiders, are unique due to their sideways and backward walking habits. They have eight eyes and possess a short, wide, flat body. They usually hide in flowers to ambush their prey.

Some of the genera within the family include Misumena, Misumenoides, and Xysticus. Let’s take a closer look at these genera and their most known species.

Misumena vatia is a common species found in the Misumena genus. They are often called flower spiders or goldenrod spiders as they come in white and yellow color variations. They can change color between white and yellow in about 10 days, which helps them camouflage in flowers.

Misumenoides formosipes is a species in the Misumenoides genus. They are intriguing for their more vibrant coloration that helps them blend into flowers, attracting prey such as bees and butterflies.

In the Xysticus genus, Thomisus spectabilis is a notable species. Known for their distinct spiny legs, these spiders are often found in fields, prairies, and woodland areas, camouflaging in their environment to catch their prey.

These are some of their shared features:

  • They have eight eyes
  • They usually hold their two front pairs of legs open to grab prey
  • They primarily ambush their prey in flowers

Here is a comparison table of their distinctions:

Genera Notable Species Primary Color Variations Habitat
Misumena Misumena vatia White, Yellow Flowers
Misumenoides Misumenoides formosipes Vibrant colors Flowers
Xysticus Thomisus spectabilis Light green, white Fields, Prairies, Woodlands

Remember, these friendly-looking spiders are beneficial to gardens and ecosystems as they help control insects and maintain a balanced environment.

Detailed Behavior Pattern

Crab spiders exhibit fascinating behavior patterns. They are unique and differ from other spider species. Let’s dive into some aspects of their behavior:

Diurnal: Crab spiders are diurnal, meaning they are active during the day. They tend to hunt for prey when the sun is out, and rest during the night.

Solitary: These creatures prefer to be alone most of the time. They do not form colonies or group together.

Hunting Technique:

  • They don’t make webs
  • They rely on ambush to capture prey
  • They wait motionlessly in flowers for prey to approach

Color-changing ability: Some species, like the Goldenrod Crab Spider, can change their color to blend in with flowers for effective camouflage.

Aggressive Vs. Non-aggressive:

  • Crab spiders are aggressive towards their prey
  • They grab and bite their victims quickly
  • They are not aggressive towards humans and tend to avoid encounters with us

To sum up, crab spiders are fascinating creatures that prefer an independent lifestyle. They actively hunt during the day, are aggressive towards their prey, but remain non-aggressive to humans. By using ambush techniques and sometimes having the ability to change color, they are efficient predators in their environment. Remember, you can always find more information on specific crab spider species if you’re interested in learning more!

Reproductive Information

When it comes to crab spiders, their reproductive process is quite fascinating. They usually lay their eggs during the spring and early summer season. The females deposit a large number of eggs inside a silk sac, which they skillfully craft to protect their offspring.

These spiderlings emerge from their eggs as miniature versions of their adult selves. As they grow, they molt, shedding their outer layers and developing new ones until they reach their full size. Sexual dimorphism is sometimes present in crab spider species, with males often being smaller and less colorful than females.

Mating is an essential aspect of crab spider reproduction. The males search for potential mates, and when they find one, they approach her cautiously. They use their heightened sense of touch to send signals, letting the female know they’re not a threat or potential prey.

In some species of crab spiders, males perform intricate courtship rituals to woo their mates. They may vibrate their abdomens or tap their front legs in a specific pattern, which signals to the female that they’re interested in mating. If the female finds the male suitable, she’ll allow him to mate with her.

It’s important to note that crab spiders exhibit diverse reproductive behaviors based on their specific type and habitat. Understanding the various aspects of their reproductive process gives insights into their unique biology and contributes to the overall knowledge of the fascinating world of spiders.

Predators and Threats

Crab spiders are skilled predators and play a role in maintaining balance in their ecosystems. Their diet mainly consists of various arthropods, but they’re also known to consume pollen and nectar occasionally1. Despite their predatory nature, they face threats from a few natural predators as well.

Birds and Lizards

Some common predators of crab spiders include birds and lizards2. They rely on their ability to blend into their surroundings, using camouflage colors to remain undetected and avoid becoming a meal.

Humans

Humans don’t typically eat crab spiders, but they can be a threat when they come into contact with them. Though not considered dangerous to humans, crab spiders can bite, usually if they feel threatened or when trapped. The bite is not venomous and isn’t harmful; it may cause mild pain and swelling.

Camouflage

Crab spiders are known for their ability to change color depending on their environment. The Goldenrod Crab Spider, for example, can switch between yellow and white, taking up to six days or 10-25 days to change their color, respectively3. This ability helps them stay concealed from both prey and predators.

Bold Text Example

Camouflage plays a vital role in a crab spider’s survival, enabling them to avoid detection from natural threats.

In summary:

  • Crab spiders are predatory arachnids that occasionally consume pollen and nectar
  • They face threats from birds, lizards, and humans
  • Their color-changing ability allows them to avoid being spotted by predators
  • The bites from crab spiders aren’t venomous or harmful to humans

Specific Species of Crab Spiders

The Flower Crab Spider is a master of disguise, hiding in flowers to ambush their prey. These tiny predators primarily consume pollinators such as bees and butterflies. By blending in with the environment, they can wait undetected for their meal to come to them.

Goldenrod Crab Spiders are often mistaken for flower crab spiders, but they have their own unique features. Their primary food source is also pollinating insects, which they capture by using their long legs and potent venom.

When it comes to Giant Crab Spiders, they are known for their large size and impressive hunting abilities. These spiders can be found hunting at night, feeding on a variety of insects and small vertebrates. Due to their size, they are even able to catch and consume small reptiles.

Bassaniana spiders, on the other hand, prefer to dwell on tree trunks and other surfaces. They vary in color to blend in with the surroundings and catch their prey, which consists of insects, moths, and flies.

Different species of crab spiders have their preferences, but overall, their diet consists of:

  • Bees
  • Butterflies
  • Moths
  • Flies
  • Small vertebrates (in the case of giant crab spiders)

Below is a comparison table to quickly illustrate the main differences between these crab spider species:

Species Habitat Diet Hunting Strategy
Flower Crab Spiders Flowers Pollinators (bees, butterflies) Ambush
Goldenrod Crab Spider Flowers Pollinators (bees, butterflies) Wait-and-grab
Giant Crab Spiders Trees, walls Insects, small vertebrates Active nighttime hunting
Bassaniana Tree trunks Insects, moths, flies Ambush

Now that you have an idea about the specific species of crab spiders and their diets, you can better appreciate the diversity of these fascinating creatures and their varied hunting strategies.

Safety Measures and Control

When dealing with crab spiders, it’s essential to have proper safety measures and control methods in place. These spiders can be beneficial insects, as they help control common pests in your garden, but it’s still crucial to keep their population in check.

First, identify the spider species you’re dealing with. This ensures you take the correct approach in handling them. Next, always wear gloves when working in the garden to protect your hands from spider bites.

Crab spiders don’t make webs but do rely on clever camouflage to ambush their prey. So, regularly check plants for their presence and remove any unwanted spiders. To keep their population under control, consider the following:

  • Using natural predators like birds and other insects to help control crab spiders.
  • Introducing pest-resistant plants that are less appealing to the spiders and their prey.
  • Chemical controls should only be used as a last resort, as they can harm other beneficial insects.

Comparison Table: Crab Spider Control Methods

Method Pros Cons
Natural Predators Eco-friendly, no chemicals Might disturb ecosystem
Pest-resistant Plants Long-term solution, less maintenance Limited plant variety
Chemical Controls Quick results Harms beneficial insects

In conclusion, maintaining a balance in your garden, encouraging natural predators, and using pest-resistant plants can help you control the population of crab spiders while protecting the environment.

Crab Spiders Roles in Ecosystem

Crab spiders play an essential role in maintaining balance within ecosystems. These small arthropods, part of the invertebrate family, help control populations of various pests. For instance, they feast on insects such as flies, mosquitos, and aphids, which can harm plants and cause discomfort for humans.

Their choice of habitat is usually flowers or other vegetation, where they lay in ambush for their prey. Interestingly, some species can change their color to blend in with their surroundings, like the flower spider or goldenrod spider, which can switch between white and yellow. This makes it easier for them to catch prey visiting flowers.

Another benefit of crab spiders in our environment is that they serve as food for other animals. As part of the food web, they are consumed by predators such as shrews, birds, and other invertebrates. This helps maintain a balance, supporting overall ecosystem health.

In summary:

  • Key role: pest control in gardens and flower beds
  • Habitat: mostly found on flowers and vegetation
  • Abilities: some can change color to blend in with surroundings
  • Part of the food web: eaten by predators like shrews, birds, and other invertebrates

Always remember that crab spiders, despite their somewhat frightening appearance, aid our ecosystem by reducing insect populations and becoming an essential part of the food chain. So next time you spot a crab spider, appreciate the role it plays in keeping your garden healthy and balanced.

Conclusion

In summary, crab spiders are fascinating creatures with unique features. They have adapted to their surroundings, enabling them to thrive in various environments such as deserts and mountains. With their ability to change color like the Goldenrod Crab Spider, they have evolved to become efficient predators. Their diet mainly consists of insects, which they capture using their strong legs and impressive sight.

Throughout history, crab spiders have been recognized for their diverse appearances and behaviors. When observing their feeding habits, pictures can often capture the intricate detail in their methods of capturing prey. A unique aspect of their life cycle is the process of shedding their exoskeleton as they grow.

In comparison to other spiders, crab spiders differ in several ways, including:

  • Their crab-like appearance with robust, stout legs
  • Ability to walk sideways, forward, or backward
  • Color-changing capabilities in some species
  • Predominantly ambush predators, rather than relying heavily on webs

Remember, when exploring the world of crab spiders, appreciate the role they play as natural pest controllers and their unique adaptations that have allowed them to survive and thrive in various habitats across the globe.

Footnotes

  1. https://ohioline.osu.edu/factsheet/ent-70

  2. https://mdc.mo.gov/discover-nature/field-guide/northern-crab-spider

  3. https://moore.ces.ncsu.edu/2021/05/crabspiders/

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Crab Spider eats Skipper

 

Bugman, an addition for your Food chain page…
Hello, Bugman! Noticed this camoflauged Crab Spider munching on a Sleeping Orange. I thought of the greatest insect website (yours of course), and took a few pictures for your Food Chain page. Enjoy! Big fan of yours,
Rachel Elizabeth
Dawson, GA

Hi Rachel Elizabeth,
You packed so many glowing compliments into your short note, and a wonderful image as well. How could we possibly not post your fabulous Crab Spider, which in this case earns its other common name, Flower Spider.

Letter 2 – Crab Spider eats unknown Moth in South Africa

 

Poor guy
Tue, Jan 6, 2009 at 8:22 AM
Any idea for either the moth or spider?
Photographed in the Langeberg Range in South Africa in montane fynbos ecosystem. Photo is attached
Brett
Langeberg Range in South Africa

Crab Spider catches Moth
Crab Spider catches Moth

Hi again Brett,
We haven’t a clue about the moth, but the spider is a Crab Spider in the family Thomisidae. Crab Spiders don’t build webs, and many species sit camouflaged in flowers awaiting pollinating insects.

Update: Crab Spider eats unknown Moth in South Africa
Tue, Jan 6, 2009
Hi Daniel:
I can’t resist a twofer. The photo provides only a partial underside view of the moth, which looks like a Geometrid to me. Unfortunately, from the perspective of providing an identification, West Cape Province has over a 100 species of Geometridae and South Africa as a whole apparently has over 1000 species, most of them dressed in cryptic grays and sepias. The spider is indeed in the Thomisidae family, likely a flower crab spider in the genus Thomisus , of which there are at least 15 to choose from. The closest match I could find was T. citrinellus . Regards.
Karl

Letter 3 – Crab Spider Eats Skipper

 

misumenoides formosipes eats butterfly
Thu, Feb 5, 2009 at 10:46 AM
Hi,
I found this crab spider at my aunt’s house in central Oklahoma last summer. I’m pretty sure it’s misumenoides formosipes, but I’m not positive. I hope you guys enjoy the pictures. Thanks for the great site!
Josh Kouri
Oklahoma City, Ok

Crab Spider eats Skipper
Crab Spider eats Skipper

Hi Josh,
We believe you have correctly identified your spider as Misumenoides formosipes, the White Banded Crab Spider.  This is a highly variable species and simply perusing some of the images submitted to BugGuide will reveal the many color variations.  It is not true that Crab Spiders can change their coloration with their surroundings.  What is more likely is that the offspring that match the color of the surroundings are more likely to survive to adulthood.  At any rate, your photo nicely illustrates how closely a Crab Spider is capable of matching its surroundings, and how effective this is in capturing prey.  It appears the butterfly in your photo is a Skipper.

 

Crab Spider
Crab Spider

Letter 4 – Crab Spider eats Hummingbird Clearwing

 

Whats for supper?
Location: Coal Creek, Queens County, New Brunswick
December 9, 2010 5:24 pm
Hi, I found a Goldenrod Crab Spider on a lilac bush with another bug clasped in its jaws. Is the Goldenrod’s prey a Hummingbird Moth? If so do you know what species it is?
Signature: Christophe

Crab Spider eats Hummingbird Clearwing

Hi Christophe,
We went back through some old mail today to try to answer a few questions we did not respond to this past month and we came across you awesome photograph.  We are guessing that this photo was taken some time before it was submitted because lilacs bloom in the spring.  The Crab Spider has captured a much larger Clearwing Moth in the genus
Hemaris, and we believe it is the Hummingbird Clearing, Hemaris thysbe.  You can compare your image to the photographs posted on the Sphingidae of the Americas Website.

Letter 5 – Crab Spider eats Bee

 

Spider eating bee
Location: Vancouver Island BC Canada
August 1, 2011 3:34 pm
My friend in Mill Bay on Vancouver Island, BC Canada took this picture this morning on his daisies. A voracious little white spider that is enormously successful capturing and killing other insects. What is this spider’s name?
Signature: Sharon J

Crab Spider Eats Bee

Hi Sharon,
The scientific name for your spider is
Misumena vatia, and it has several common names, including Crab Spider because of its general shape, and Flower Spider because of its habit of waiting on flowers for pollinating insects.  Crab Spiders are able to change color to match their surroundings, and your white Crab Spider blends perfectly with the white petals of the blossom.

Letter 6 – Crab Spider Eats Skipper

 

Crab Spider? eating a skipper?
Location: Charleston, SC
September 19, 2011 12:15 pm
This was photographed just outside of Charleston, SC in a monastery called Mepkin Abbey. I found these two in small purple flowers growing along one of their many paths.
Signature: Steven

Crab Spider Eats Skipper

Hi Steven,
Your photo of a Crab Spider in the family Thomisidae feeding on a Skipper in the family Hesperiidae is an excellent addition to our Food Chain tag.  This is at least the fourth entry we have received documenting this particular predator/prey combination.  Crab Spiders are hunting spiders that do not spin a web, and several species are typically found hiding well camouflaged in blossoms awaiting hapless pollinating insects including Skippers.  Skippers are butterflies that are typically considered to be a transitional family between butterflies and moths, and they get their common name from their quick, darting flight.

Letter 7 – Crab Spider eats Pipevine Swallowtail

 

Subject:  spider on black swallowtail
Geographic location of the bug:  Auburn, California
Date: 04/17/2019
Time: 01:08 PM EDT
Your letter to the bugman:  I thought this was a cool image of a spider incapacitating a black swallowtail. This was along a trail, near the flowers the butterfly was feeding on. Maybe a crab spider? Enjoy!
How you want your letter signed:  k. cassidy

Crab Spider eats Pipevine Swallowtail

Dear k. cassidy,
This is an awesome image.  We agree that this is a Crab Spider.  Crab Spiders do not build webs to snare prey.  Many species, especially pastel colored, pink, yellow or white Crab Spiders, are camouflaged in blossoms where they wait to ambush pollinating prey like bees and butterflies.  Your Swallowtail is actually a Pipevine Swallowtail.  Did you witness the Crab Spider capture the Pipevine Swallowtail?  If not, was the Swallowtail still alive when you encountered this awesome Food Chain illustration, though interestingly, this is not the first time we have received documentation of a Crab Spider eating a Pipevine Swallowtail.

yes, love the pipevine swallowtails this time of year (here they like the lilac and brodiaea best). I did not see it in the capturing phase, but this butterfly was still alive though incapacitated. Seemingly big prey, but the spider had him for sure! This is in the Auburn State Recreation Area along the American River in Northern California.
Thanks for the ink to the other crab spider catching a pipevine! I didn’t see that when I first searched.
Enjoy and share the image!
thanks,
kerrie

Authors

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  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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