Pantropical Jumping Spider (Plexippus paykulli)

Physical description and identification

The pantropical jumping spider is a sturdy, medium-to-large salticid that most people meet on a wall rather than in a flower bed. It is one of the few jumping spiders thoroughly at home on buildings, and is often the spider beside a porch light, swivelling its whole body to face you as you pass.

Adults

• Size: females measure 9–12 mm in body length and males 8–11 mm — large for a jumping spider, comparable with a bold jumper, although salticid legs stay short and strong rather than long.
• Male colour: velvety dark brown to black, with a crisp white line running down the centre of the carapace and onto the front of the abdomen, two clean white spots at the rear separated by a dark bar, and white bands edging the carapace. A central stripe plus two separate rear spots is the quickest field mark.
• Female colour: larger, duller and greyer, with a broad pale median band and finely mottled sides, and without the sharply defined pair of rear spots.
• Eyes: eight eyes in four rows — an enormous forward-facing principal pair flanked by a smaller forward pair, then small lateral eyes wrapping around the head for nearly all-round motion detection. See our guide to spider eyes.
• Other features: a high, flat-topped, distinctly rectangular carapace; legs banded light and dark with a thickened first pair; mature males with swollen pedipalp tips.

Eggs and egg sac

The female builds a thick, closed silk retreat in a sheltered crevice — behind a shutter, inside a window frame, under loose bark or in a rolled leaf — and lays a flattened white egg sac inside it. She seals herself in with the sac and guards it, feeding little or not at all until the young emerge, and produces several sacs over a season.

Spiderlings

Hatchlings are pale, translucent miniatures with eyes that look far too big for them. They remain in the maternal retreat through their first moult, then leave and begin hunting springtails almost immediately, dispersing on foot, along short silk bridges and sometimes on air currents. Each later moult happens inside a fresh silk chamber — see our guide to spider molting.

Hunting, not a web

This spider builds no capture web of any kind, and any page describing a Plexippus paykulli “web” is really describing its sleeping bag. Silk serves three purposes only: the closed retreat, the egg sac, and the dragline it pays out before every leap — a safety rope that also works as a brake and a rudder, letting the spider control its body angle in mid-air. Hunting is purely visual: the side eyes pick up movement, the spider turns to bring the principal eyes to bear, creeps forward in stop-start bursts, then extends its third and fourth legs explosively. That launch is powered by leg muscle together with a surge of internal fluid pressure, because the joints involved carry no extensor muscles of their own. For spiders that do build traps, see our guide to spider webs.

Where the pantropical jumping spider lives

The name is accurate: Plexippus paykulli is one of a handful of spiders found right around the tropical belt. It is generally treated as an Old World species, widespread across Africa and southern Asia, that has been carried worldwide in cargo, timber and nursery plants. It is now firmly established in the Americas, so the older claim that it is confined to Asia and Africa is out of date.

In the United States it is a familiar building spider across the Gulf and south Atlantic states, with strong populations in Florida, Georgia, Alabama, Louisiana and Texas, plus Hawaii and the Caribbean. It also occurs through Central and South America, across tropical Asia from India to Japan, and on many oceanic islands. Cold winters, not heat, set the northern limit.

Its habitat is vertical and sunlit: walls, fence posts, railings, stone piles and tree trunks, and indoors on window frames and garage walls — one reason it appears on lists of common house spiders in warm regions. It is also a genuine field spider, recorded among the commoner foliage predators in cotton, rice and vegetable crops, where it takes leafhoppers and small caterpillars.

Are pantropical jumping spiders venomous?

Yes, in the sense that nearly every spider is venomous: the pantropical jumping spider injects venom to subdue the insects it catches. It is not medically significant to people or pets. The venom is tuned to small arthropods, the dose is minute, and no serious envenomation has been documented from this species or any other member of the family Salticidae. No antivenom exists for jumping spiders because none is needed — quite unlike the recluse and widow spiders, whose venoms act directly on human tissue and nerves.

Can pantropical jumping spiders bite?

They can, but it takes real provocation. A jumping spider that notices a hand either turns to watch or leaps away on its dragline. Bites happen when a spider is squeezed inside clothing, pressed against skin while being brushed off, or grabbed in a closed fist — and even then the short fangs often fail to break the skin.

A bite that does connect produces a brief pinprick, sometimes a small red bump and a little itching, and it settles within a few hours to a day. Wash the area with soap and water, apply a cold pack if it is sore, and leave it alone. Seek medical advice only if swelling spreads well beyond the bite, if hives or breathing difficulty develop — an allergic reaction rather than the venom itself — or if the site turns hot and increasingly painful after a couple of days.

Ecological importance and behavior of the pantropical jumping spider

This is a diurnal, free-ranging hunter with an unusual extra habit: it is one of the jumping spiders that keeps working after sunset around artificial light. Porch lamps and lit shop fronts pull in moths, midges and small beetles, and the spiders patrol the wall beside them. By day the same individuals stalk flies, ants, leafhoppers and other spiders across sunlit masonry and foliage.

Courtship: males display visually — front legs raised and waved, the body rocked so the white stripes catch the light — then sidle in cautiously, since a salticid female is quite capable of eating a careless suitor. Males also fence over a good hunting wall, and the loser retreats unharmed.

Natural predators: geckos and anoles are probably the most important on buildings, along with birds, mantises, ants and larger spiders. Spider-hunting wasps paralyse salticids and seal them into nests as living food for their larvae, and a few tropical jumpers specialise in hunting other jumping spiders.

Seasonal behaviour: in the true tropics all life stages occur year-round. Toward the edges of the range adults mature in spring and early summer, egg sacs follow through the warm months, and winter is passed by juveniles sealed in silk retreats. Individuals live roughly a year; the old claim of a three-year lifespan is not supported for a salticid of this size.

Relationship with humans: entirely positive. The spider is harmless and removes flies, mosquitoes and small pests from the walls it lives on. A cup and a card returns an indoor wanderer to the garden; spraying a wall removes the predator along with the pests.

Similar spiders and how to tell them apart

Quick facts

Did you know?

• The species honours the Swedish entomologist Gustaf von Paykull and was described in 1826 by Jean Victor Audouin, from material collected on the French scientific expedition to Egypt.
• Jumping spiders have the sharpest eyes of any animal their size. The principal eyes work like a telephoto lens, and the retina itself is swung about by muscles so the spider can scan a scene without moving its head.
• The popular claim that jumping spiders leap fifty times their body length is an exaggeration. High-speed measurements put a typical exploratory jump at a few body lengths, with the longest recorded leaps around six times body length.
• Because the jump depends partly on internal fluid pressure, a dehydrated or freshly moulted jumping spider genuinely cannot jump well and has to walk until its body pressure recovers.

In summary, the pantropical jumping spider is a harmless, sharp-eyed, wall-dwelling hunter that has spread with human trade across the tropical world. Learn the white median stripe and the two rear spots of the male and you will recognise it instantly — and you will be looking at one of the most effective free pest controllers on the outside of your house.