Phidippus carneus
One of the larger jumping spiders of the American Southwest and northern Mexico: a heavy-bodied hunter with a black front end, a deep red abdomen and crisp white bands on black legs. It lives on desert shrubs, cactus and oaks, builds no snare, and takes its insect prey with a single calculated jump on the end of a silk safety line.
By Dr Richard J. Pearce (PhD)Published May 17, 2022Updated September 13, 2026✓ Reviewed by Dr. James Watuwa
In this guide
Physical description and identification
Phidippus carneus is a big, solidly built member of the Salticidae and one of the most striking spiders of the arid borderlands. Everything about it says jumping spider: a high, blunt-fronted carapace carrying two enormous forward eyes, short powerful legs, a dense pelt of coloured scales, and the habit of pivoting to face whatever is watching it. Within Phidippus it belongs to the group of large red-abdomened species of the Southwest.
Adults
- Size: roughly 15–17 mm (0.6–0.7 in) in body length, which puts it among the largest jumping spiders in North America. Females are the heavier sex; males are slimmer with longer legs.
- Colour: the carapace is black and velvety, the abdomen a deep brick to scarlet red. Females commonly carry a dark stripe running lengthways down the middle of the red abdomen, and the red itself is often a little duller than in the male.
- Legs: black, thickset, and marked with distinct pale to white bands — the single most useful field character, because the banding is far crisper here than in most red Phidippus.
- Eyes: eight in four pairs. The two central forward-facing eyes are exceptionally large and give sharp, colour, image-forming vision; the smaller side and top eyes are wide-angle motion detectors that cover almost the full circle around the spider. Our guide to spider eyes explains how the two systems work together.
- Other features: the chelicerae are iridescent, flashing metallic green in direct light, and the body and legs are covered in setae — fine hairs and flattened scales that carry the colour and also register air movement and touch.
Eggs and egg sac
The female spins a dense, flattened silk chamber in a protected place — most often under a rock or slab, but also under bark and in curled leaves — and lays her eggs inside it in a papery sac. She closes herself in and guards the clutch rather than abandoning it, which is why the sacs are almost never found exposed.
Spiderlings
The young hatch inside the nest and stay with the mother through their first moult or two before scattering to build their own small silk retreats. They already have the adult eye pattern but none of the adult colour, and the red abdomen develops gradually over successive moults. Every moult is carried out inside a sealed silk chamber, because a freshly moulted spider is soft and defenceless for several hours.
Hunting and the use of silk
This species builds no capture web. It hunts on foot in daylight, using the side eyes to catch movement, turning to bring the principal eyes on target, then stalking to within jumping range. The leap itself is hydraulic: spiders have no extensor muscle at the key leg joints and instead force body fluid into the hind legs to straighten them explosively. A silk dragline is fixed to the surface first, so a misjudged jump leaves the spider swinging on a line instead of falling. Silk is also spun into flattened tubular nests used for sleeping, moulting, sheltering from heat and cold, and egg-laying — these spiders are not burrowers and do not dig underground shelters.
Where Phidippus carneus lives
Phidippus carneus is a spider of the American Southwest and the Mexican highlands. Records run from Arizona and New Mexico through west Texas and south into central Mexico. It is a warm, dry-country species and is not found in the humid east or on the Pacific coast.
Its habitat is desert and semi-desert vegetation: creosote, mesquite, acacia and other desert shrubs, prickly pear and other cactus, yucca, and the oaks of foothill and canyon woodland. It hunts among branches and pads rather than on open ground, and retreats to silk nests under rocks, in bark crevices and among the bases of spiny plants. Around people it turns up on ornamental cactus, garden shrubs and adobe walls, but it is not a house spider and does not colonise buildings.
Are Phidippus carneus spiders venomous?
Yes, in the same way that almost every spider is venomous: it injects venom through its fangs to immobilise insects. That venom has no medical significance for humans or pets. Jumping spiders as a family have never produced a dangerous bite anywhere in the world; the dose is minute and the chemistry is tuned to small arthropods. Being a large salticid makes Phidippus carneus more capable of piercing skin than a tiny species, but the effect is still trivial, and it is completely unrelated to the recluse and widow spiders that account for the medically serious bites in the region.
Can Phidippus carneus spiders bite?
It can, and because of its size a defensive bite from this species is more likely to be felt than one from a small jumper — but it still amounts to a pinch. Bites happen only when the spider is trapped: held in a closed hand, pressed inside a glove or clothing, or squeezed while being brushed off. Left alone, the spider's response to a person is to turn, watch, and then sidestep away or drop on its dragline.
A bite causes brief sharp pain, a small red mark and sometimes mild itching, all of which usually settle within a few hours. Wash the site with soap and water, use a cold pack for the sting, and keep it clean. Medical advice is warranted only if swelling spreads well beyond the bite, if hives or breathing trouble develop, which would point to an allergic reaction rather than the venom, or if the wound later shows signs of infection.
Red spider, no panic: a red abdomen on a spider in the Southwest often triggers thoughts of a widow. Widows are glossy, hairless, long-legged spiders that hang upside down in a messy tangle web with a red hourglass on the underside. Phidippus carneus is furry, short-legged, sits in the open on plants, builds no web, and carries its red on the top of the abdomen.
Ecological importance and behavior of Phidippus carneus
This is a diurnal visual hunter. It is active in sunshine, moves in the characteristic stop-start pattern of a spider that scans between steps, and spends nights and cold spells sealed inside a silk nest. Prey is stalked deliberately, sometimes over many centimetres, before the final leap; the front legs are thrown forward to grip and the fangs go in on contact. A spider of this size can subdue prey that other salticids cannot.
Diet: flies, moths, bees and wasps, beetles, true bugs, grasshopper nymphs, caterpillars and other spiders. In desert scrub and orchards this makes it a genuinely useful predator of pest insects, which is why growers and gardeners generally welcome it.
Natural predators: insect-eating birds, lizards, mantises, robber flies, larger spiders, and spider-hunting wasps that paralyse salticids and seal them into nest cells as living food for their larvae.
Courtship: males find females by following their draglines, then perform a silent visual display in front of them — legs raised and waved, body rocking, abdomen vibrating. The female decides. An unreceptive one drives the male off, and courtship at close range is genuinely dangerous for him.
Seasonal cycle: juveniles overwinter part-grown inside silk nests, mature in spring, and adults are most obvious through the warm months. Typical lifespan is one to two years, with big females the most likely to see a second season.
Relationship with humans: harmless and beneficial. A carneus found on a patio plant needs nothing done about it; coaxed onto a stick or a card it will walk away without trouble.
Similar spiders and how to tell them apart
| Spider | How it differs from Phidippus carneus |
|---|---|
| Apache jumping spider (Phidippus apacheanus) | Shares the black-and-red look and much of the range, but is smaller, the red is usually a brighter flame orange covering the whole upper abdomen, and the legs lack the bold white banding. |
| Phidippus texanus | Noticeably smaller at around 12 mm. Males are orange rather than deep red; females are pale and marbled, nothing like the red-and-black carneus. |
| Cardinal jumping spider (Phidippus cardinalis) | A slimmer, ant-mimicking red-and-black jumper of the east and southeast; its red is more uniform and its range barely overlaps. |
| Phidippus californicus | Another red-and-black western species, but usually with a clear pattern of black chevrons or spots interrupting the red, and centred further west. |
| Western black widow (Latrodectus hesperus) | Glossy and hairless with long thin legs, hangs upside down in a tangle web, and carries a red hourglass beneath the abdomen. Medically significant, and nothing like a jumping spider in shape or behaviour. |
Quick facts
| Distribution | Southwestern United States — Arizona, New Mexico and west Texas — south to central Mexico. |
|---|---|
| Habitat | Desert and semi-desert shrubs, cactus and yucca, and foothill oak woodland. |
| Diet | Flies, moths, bees and wasps, beetles, bugs, grasshopper nymphs, caterpillars and other spiders. |
| Lifespan | One to two years; juveniles overwinter in silk nests. |
| Predators | Birds, lizards, mantises, robber flies, larger spiders and spider-hunting wasps. |
| Web | No capture web. Silk is used for draglines and for flattened tubular nests under rocks and bark. |
| Activity | Diurnal; hunts by sight in bright sun. |
| IUCN status | Not evaluated. Widespread within its range. |
Did you know?
- The species name comes from the Latin carneus, meaning flesh-coloured — a reference to the reddish body, and the same root that gives English words such as carnation and carnal.
- The metallic green of the chelicerae is structural colour produced by microscopic layers in the cuticle rather than by pigment, which is why it shifts and disappears as the angle of the light changes.
- A jumping spider's principal eyes focus by moving the retina, not the lens: muscles swing the tube-shaped back of each eye behind a fixed lens to scan the image.
- Because leg extension is hydraulic, a dehydrated or injured jumping spider physically loses its ability to jump — the legs still bend, but there is not enough pressure to straighten them fast.
In summary, Phidippus carneus is a large, handsome, entirely harmless hunter of southwestern desert scrub and oak country. The combination of size, deep red abdomen and white-banded black legs identifies it, and its only meaningful effect on people is the steady supply of insects it removes from the garden.
Frequently asked questions about the phidippus carneus spider
What does a Phidippus carneus spider look like?
It is a large, furry jumping spider with a black velvety carapace, a deep brick-red to scarlet abdomen and black legs marked with clear white bands. The chelicerae flash metallic green in direct light. Adults are about 15 to 17 millimetres long, which makes it one of the biggest jumpers in North America.
How can you tell a female Phidippus carneus from a male?
Females are the bulkier sex and usually carry a dark stripe running lengthways down the centre of the red abdomen, with slightly duller red overall. Males are slimmer, with proportionally longer legs, swollen pedipalps beside the face and, typically, a cleaner and more saturated red abdomen.
How big does Phidippus carneus get?
Adults reach roughly 15 to 17 millimetres in body length, about 0.6 to 0.7 inches, with a leg span close to twice that. It is among the largest jumping spiders in North America, noticeably heavier than the familiar bold jumper and roughly half again the length of Phidippus texanus.
Is Phidippus carneus venomous or dangerous?
It has venom and uses it on insects, but it is not dangerous to people or pets. No jumping spider anywhere is medically significant. Its size means a bite is more likely to be felt than that of a small jumper, yet the result is still only a brief pinch with a little redness.
Does Phidippus carneus bite people?
Only when trapped against skin, such as inside a glove or a closed hand. A bite gives a short sharp pain, a small red mark and sometimes mild itching, settling within a few hours. Wash the spot, use a cold pack, and seek advice only if swelling spreads or hives and breathing trouble appear.
Do Phidippus carneus spiders build webs or live underground?
Neither. They build no capture web and they do not dig burrows. They spin flattened tubular silk nests tucked under rocks, loose bark and curled leaves, and use them for resting, moulting, sheltering from weather and laying eggs. Silk is also spun as a dragline before every jump.
Why do these spiders jump instead of spinning a snare?
Jumping spiders hunt by sight rather than by ambush in silk. Excellent eyes let them detect, identify and stalk prey, and the jump delivers the fangs faster than an insect can react. Leg extension is hydraulic, driven by body fluid pressure, because spiders lack extensor muscles at the key joints.
Where does Phidippus carneus live?
It occupies the arid southwestern United States and northern and central Mexico, with records from Arizona, New Mexico and west Texas southward. Typical habitat is desert and semi-desert shrubland with creosote, mesquite and cactus, plus foothill oak woodland, where it hunts among branches, pads and foliage.
Where does a female Phidippus carneus lay her eggs?
She spins a dense, flattened silk chamber in a sheltered spot, most often beneath a rock or slab, and lays her eggs inside it in a papery sac. She seals herself in and guards the clutch until the spiderlings hatch and complete their first moults rather than leaving it unattended.
Could a red jumping spider be a black widow?
No. Widows are glossy and hairless with long thin legs, hang upside down in a tangle web, and show a red hourglass on the underside of the abdomen. Phidippus carneus is hairy and short-legged, sits in the open on plants, builds no web, and wears its red on top.
References
- World Spider Catalog (2026). Phidippus carneus G. W. Peckham & E. G. Peckham, 1896. Natural History Museum Bern. wsc.nmbe.ch/spec-data/38445/taxon
