European Garden Spider (Araneus diadematus): Orb Weaver Facts

What does a European garden spider look like?

The European garden spider is also called the cross spider, cross orbweaver, diadem spider or crowned orb weaver, and in North America sometimes the pumpkin spider, a name it shares with the related Araneus marmoreus. All of these names point to its look: a large, rounded abdomen marked with a cross of white or cream spots.

The background color varies a lot, from pale yellow and orange through reddish brown to dark gray. The white markings are made by cells packed with guanine, a waste product of protein breakdown that the spider stores under its skin rather than excreting. The legs are banded light and dark and carry stiff spines.

Like most orb weavers, the garden spider has eight small eyes and poor eyesight. It hardly needs vision: almost everything it knows about the world reaches it as vibrations through the threads of its web.

Males look quite different from females. They are smaller, with a slimmer abdomen, relatively longer legs and swollen pedipalps, the short leg-like organs near the mouth that males use to transfer sperm.

Several relatives look similar. In Europe the four-spot orb weaver (Araneus quadratus) is just as bulky but usually shows four large white spots rather than a full cross, and it favors tall grass and heath rather than shrubs. In North America the marbled orb weaver (Araneus marmoreus), also nicknamed the pumpkin spider, often has a bright orange or yellow abdomen with dark marbling. Checking for the clear cross on the back is the quickest way to recognize A. diadematus.

How big is a garden spider?

Females are much bigger than males. Adult females measure 6.5–20 mm (0.26–0.79 in) in body length, while adult males reach 5.5–13 mm (0.22–0.51 in). A large autumn female with her legs spread across the web can span roughly the size of a coin, which is why she seems to appear suddenly at that time of year.

Spider weights are rarely measured, but even the heaviest egg-laden females weigh well under a gram.

Habitat and range

The garden spider is native to Europe, where it is one of the most familiar spiders from Britain and Scandinavia to the Mediterranean. It was introduced to North America and is now widespread in southern Canada and the northern United States, especially in the Northeast and the Pacific Northwest.

It lives wherever there is a frame to hang a web on and plenty of flying insects: gardens, hedges, parks, woodland edges, heaths, meadows with tall plants, fences, window frames and the walls of sheds. Sunny, sheltered spots between shrubs are favorite web sites, and the same garden can hold dozens of webs by September.

Web, silk and hunting

The European garden spider is a classic orb weaver. It builds a vertical, wheel-shaped web with a central hub, straight spokes called radii, and a sticky capture spiral. A large female’s web often measures about 20–40 cm (8–16 in) across, and the whole web can be built in under an hour. You can follow the steps in how spiders spin webs.

Orb weavers use several kinds of silk from different glands: strong dragline silk for the frame and radii, stretchy silk coated with glue droplets for the capture spiral, and other silks for wrapping prey and building egg sacs. The details are explained in how spiders make silk.

The spider waits head down at the hub, or hides in a curled leaf at the edge of the web with one leg on a signal line that runs to the center. When an insect hits the sticky spiral, the spider runs out, wraps the prey in silk, and bites it to inject venom and digestive enzymes. Prey can be left wrapped in the web and eaten later. When disturbed by a predator, a garden spider may shake its web violently until it becomes a blur, or drop to the ground on a safety line.

Webs collect dust, lose their stickiness and get torn, so garden spiders usually rebuild them often, in good weather almost daily. Before rebuilding, the spider eats much of the old web. Experiments with labeled silk in the 1970s showed that the protein from an eaten web is quickly reused to make new silk, so very little is wasted.

What does a garden spider eat?

Garden spiders eat flying insects that blunder into the web: flies, hoverflies, crane flies, moths, butterflies, aphids, wasps and bees. A large female can tackle insects bigger than herself, including dragonflies. Unwanted or dangerous items, such as large wasps, are sometimes cut out of the web instead of being wrapped.

Like other spiders, the garden spider cannot chew solid food. Its venom and digestive juices liquefy the prey’s soft tissues, and the spider sucks up the fluid, leaving a dry husk. For the bigger picture of spider diets, see what do spiders eat.

Courtship, mating and the risk of being eaten

Mating takes place in late summer and early autumn, when males stop building webs of their own and wander in search of females. A male approaches a female’s web cautiously, plucking and vibrating the threads in a special rhythm so that she does not treat him as prey. He often spins a separate mating thread at the edge of her web and coaxes her onto it.

Courtship is genuinely dangerous for the male. Females sometimes attack and eat males before, during or after mating. Research on this species has found that hungry females and males that are small compared with the female are the most likely to end up as a meal. Many males escape, however, and some mate with more than one female.

Life cycle and lifespan

The European garden spider usually lives about one year. In autumn the female spins a dense, yellowish silk cocoon, often under bark, on a wall or among leaves, and lays several hundred eggs inside it. She guards the site for a while, but typically dies with the first hard frosts of late autumn.

The eggs survive the winter, and the spiderlings hatch in spring. For the first days they cluster together in a tight ball of yellow young with a dark patch on the abdomen. If the ball is touched it bursts apart as the spiderlings scatter on silk threads, then regroups when the danger has passed.

The young then disperse, sometimes by ballooning, which means releasing silk threads that catch the breeze and carry them away. Through summer they molt several times, building ever larger webs, and they reach adult size by late summer. That is why garden spiders seem to “appear” in autumn: they were there all year, just small.

Predators and threats

Garden spiders are eaten by many animals, especially birds such as tits, wrens and robins. Spider-hunting wasps paralyze them as food for their larvae, and parasitic wasps and flies lay eggs in the spiders or their egg sacs. Other spiders, including members of the same species, are also a risk.

The species is not assessed on the IUCN Red List and is common and widespread. It is not considered threatened, although, like other insect-eaters, it depends on healthy insect populations and suffers locally where gardens are sprayed heavily or tidied of every shrub and tall plant.

Garden spiders and people

The European garden spider is harmless to people. It is shy and rarely bites, and its fangs can barely pierce human skin; a bite causes at most mild, short-lived pain. It is useful in gardens, catching large numbers of flies and other insects.

The species has a small place in the history of science and spaceflight. In 1973, two garden spiders named Arabella and Anita flew aboard the US space station Skylab in a student experiment. After a few days of adjustment, both built orb webs in near weightlessness, though the webs were less regular than on Earth.

Its familiar look also makes it a favorite for learning how spiders differ from insects, explained in spider vs insect. For a very different spider that hunts without a web, see the Carolina wolf spider.

Myths and facts

Myth: garden spiders arrive in houses and gardens in autumn. They live in the garden all year; they simply become big and noticeable as adults in late summer.

Myth: the cross spider is dangerous because it is so big. Size says little about danger. The garden spider’s venom is adapted for insects and is not a medical concern for people.

Fact: a spider’s web is recycled. Garden spiders eat their old webs and reuse much of the silk protein to spin the next one.