​Red-headed vs. Red-backed Jumping Spiders: Spot the Difference!

If you’ve ever wondered whether that tiny acrobat in your garden is a Red-headed or a Red-backed jumping spider, you’re not alone! Let’s dig into the roots of what sets these two apart. No need to leaf through textbooks, I’ve got you covered.

Geographic Origin: Where Do They Put Down Roots?

• Red-headed Jumper (Maratus griseus): This little sprout is exclusive to Australia and New Zealand. If you spot one in your backyard Down Under, you’ve likely found a Red-headed jumping spider—no passport required!
• Red-backed Jumper (Phidippus johnsoni): This species is native to western North America, thriving from the western US to parts of Canada and northern Mexico. If you’re in the Americas, it’s probably a Red-backed you’re seeing.

Size and Appearance: Small Bud vs. Big Bloom

• Red-headed Jumper: These spiders are tiny think 2–6 mm, about the size of a grain of rice. Males show off a bright red and yellow “face” (cephalothorax), but their abdomens are usually less flashy than some of their peacock spider cousins.
• Red-backed Jumper: The Red-backed is the big leaf in this garden, reaching 9–14 mm. Both males and females have a bold, bright red abdomen; females even sport a black stripe down the middle. Their heads and legs are jet black, and their mouthparts (chelicerae) shine with a teal hue—talk about a colourful bouquet!

Courtship Behaviour: Dance-Offs and Displays

• Red-headed Jumper: As a proud member of the peacock spider genus, the male Maratus griseus puts on a showy “dance,” lifting and displaying his vibrant abdominal flaps and vibrating his body to woo the ladies. It’s the ultimate garden party performance!
• Red-backed Jumper: While they still have a courtship dance, Red-backed jumpers don’t have the dramatic, fold-out abdominal flaps or the rainbow of colours seen in Maratus. Their moves are a bit more low-key, but still enough to impress.

Venom and Risk: No Need to Panic

• Both the Red-headed and Red-backed jumping spiders are members of the Salticidae family and are harmless to humans. Their bites might sting a little, but they’re not dangerous—so don’t lose your compost over it!
• Important Note: Don’t confuse these harmless jumpers with the highly venomous Redback spider (Latrodectus hasselti) of Australia, which is a completely different genus (related to the black widow). That’s a whole different plant in the garden!

So, whether you’re in Australia admiring a Red-headed jumper’s fancy footwork, or in North America spotting a Red-backed’s bold colours, you can rest easy knowing these spiders are more likely to leaf you smiling than cause any trouble. Happy spider-spotting, and may your curiosity continue to blossom!