Garden spiders are carnivores that eat primarily insects. Flies, beetles, aphids, moths, mosquitoes, and grasshoppers make up the bulk of their diet, though they’ll consume almost anything that lands in their web or crosses their path. They’re also surprisingly flexible eaters, occasionally feeding on pollen, recycled web silk, and even small vertebrates.
Common Prey Items
The specific insects a garden spider eats depend largely on what’s available and how the spider hunts. Web-building species like the black and yellow garden spider and the European garden spider (the classic orb weavers you see in backyards) catch whatever blunders into their sticky silk. Flies, beetles, aphids, mosquitoes, cicadas, moths, and wasps are all fair game. As NC State Extension puts it simply: they eat anything that doesn’t tear itself loose from the web.
Jumping spiders, another common garden resident, don’t use webs at all. They hunt during the day, stalking and pouncing on prey like house flies. Crab spiders take a different approach, flattening themselves on flowers and ambushing whatever lands nearby, including sweat bees, green bottle flies, and honey bees. The hunting method shapes the menu, but the result is the same: if it’s small enough and moves, a garden spider will try to eat it.
How They Actually Eat
Spiders can’t chew. Instead, they use a process called extraoral digestion, which essentially means they digest their food outside their body before consuming it. When prey gets caught in a web, the spider detects the vibrations through the silk strands, pinpoints the location, and rushes over to bite and wrap the struggling insect. Despite having poor eyesight, orb weavers are extraordinarily sensitive to vibrations, and by sitting at the center of the web where all the structural threads converge, they can detect exactly which strand is vibrating.
The spider’s bite delivers venom containing short neurotoxic peptides that rapidly shut down the prey’s nervous system by interfering with ion channels. But the venom does more than just paralyze. It also contains digestive enzymes that begin breaking down the prey’s internal tissues. The spider then floods the immobilized insect with additional digestive fluids, waits for the insides to liquefy, and sucks up the resulting nutrient-rich liquid. What’s left behind is a hollow, crumpled husk.
Pollen: A Surprising Part of the Diet
Garden spiders aren’t purely carnivorous. Research published in PLOS ONE found that about 25% of juvenile orb weavers’ diet consisted of pollen, with the remaining 75% coming from flying insects like small flies and wasps. Pollen grains get trapped in the sticky spiral threads of the web alongside insects, and when the spider takes down and recycles its web (which orb weavers do daily), it consumes the pollen along with the silk proteins.
This isn’t accidental ingestion. The pollen grains found in the study were too large to be swallowed passively. The spiders had to actively dissolve the outer coating of each grain using digestive enzymes before sucking up the nutrients. Researchers confirmed that the spiders incorporated pollen nutrients into their body tissue even when insect prey was available, making pollen a genuine dietary supplement rather than an incidental snack.
Web Recycling as Nutrition
Orb weavers build a fresh web every day, and the old one doesn’t go to waste. The European garden spider eats its damaged web each morning to recycle the silk proteins. Black and yellow garden spiders do the same thing at night, consuming the sticky capture strands and spinning replacements. This recycling recovers the protein investment of web construction, but it also provides a bonus: tiny insects and miscellaneous organic matter stuck to the old silk get eaten along with it.
Occasionally, Larger Prey
Most garden spiders stick to insects, but larger species sometimes punch above their weight. Black and yellow garden spiders have been documented killing and wrapping Mediterranean geckos, a feat that seems improbable for a spider but is possible when the lizard gets tangled in strong silk. Golden orb weavers in Australia build webs sturdy enough to occasionally trap small birds and bats, which the spiders will wrap and feed on. These events are rare, but they illustrate just how effective spider silk and venom can be against surprisingly large animals.
What Spiderlings Eat
Baby garden spiders, called spiderlings, emerge from egg sacs in spring, sometimes hundreds at a time. They disperse quickly, often by “ballooning” on silk threads carried by wind. Even at this tiny size, they’re already predators. Spiderlings build miniature webs and feed on other small invertebrates, including gnats, fruit flies, springtails, and mites. Their prey simply scales with their body size. As they grow and molt through successive stages, their webs get larger and their prey gets bigger.
Beneficial Insects Aren’t Spared
Garden spiders are indiscriminate predators. They don’t distinguish between pest insects and beneficial ones. Crab spiders sitting on flowers regularly catch honey bees and other pollinators alongside pest flies. Orb weavers will happily eat a butterfly, a parasitic wasp that controls caterpillars, or a ladybug that eats aphids. This can feel frustrating if you’ve planted a pollinator garden, but on balance, spiders overwhelmingly consume pest species simply because pest insects tend to outnumber beneficial ones in most gardens.
The sheer volume of insects spiders consume globally is staggering. A 2017 study estimated that the world’s spiders, collectively weighing about 25 million metric tons, kill between 400 and 800 million tons of insects and other invertebrates every year. That’s more than the weight of meat and fish consumed annually by all humans. In a garden setting, this translates to meaningful pest control, with individual spiders eating multiple insects per day throughout the growing season.