Crab spiders (family Thomisidae) are ambush predators that wait motionless on flowers, leaves, and bark for prey to come within reach. They are named for their crab-like posture — the first two pairs of legs are longer and held outstretched, and they can move sideways and backward. Arizona is home to numerous crab spider species, including the goldenrod crab spider (Misumena vatia), which can slowly change color between white and yellow to match the flower it is sitting on. Crab spiders do not spin capture webs. They are particularly common on flowering plants during Arizona's spring and monsoon seasons when pollinators are abundant. Despite their ability to catch bees and wasps much larger than themselves, they are completely harmless to humans.
👁Warning Signs
Stocky spider with outstretched front legs sitting motionless on a flower or leaf. May be white, yellow, or green to match the flower. Prey (often bees or butterflies) caught at the flower.
⚠Health & Property Risks
Not medically significant. Completely harmless to humans.
Prevention Tips
Not a pest requiring control. Highly beneficial garden predators.
🛡Professional Treatment
No treatment necessary.
Frequently Asked Questions — Crab Spider
The Crab Spider (Misumena / Misumenops spp.) is white, yellow, or green; some species can change color to match flowers and typically measures 1/4–1/2 inch body. Crab spiders (family Thomisidae) are ambush predators that wait motionless on flowers, leaves, and bark for prey to come within reach. They are named for their crab-like posture — the first two pairs.
The Crab Spider is generally low-risk, but caution is still advised. Not medically significant. Completely harmless to humans.
In Arizona, crab spiders are most often encountered in the following situations: Stocky spider with outstretched front legs sitting motionless on a flower or leaf. May be white, yellow, or green to match the flower. Prey (often bees or butterflies) caught at the flower.
The Crab Spider is most active during: Most active during spring and monsoon season when flowers are abundant. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.
Not a pest requiring control. Highly beneficial garden predators.
No treatment necessary.
If you spot a Crab Spider indoors, avoid handling it directly. Capture it under a glass if possible for identification, or photograph it for reference. Contact Pest Control Bros for a professional inspection — we can confirm the species, assess the severity of the infestation, and recommend targeted treatment.
Dealing with Crab Spider?
Pest Control Bros LLC serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa. No contracts. Free inspections. Same-week service.
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