European garden spider

Systematic position: The European garden spider (Araneus diadematus, often misidentified as Araneus atricus) belongs to the order Araneae and the family Araneidae. Contrary to some classifications, it is an obligate predator, not a plant-feeding pest, and plays a neutral to beneficial role in agro-ecosystems.

Biology and life cycle: The species completes its life cycle within a single year. Females lay eggs in a silk cocoon in late autumn, which protects them through the winter. Spiderlings emerge in the spring and disperse to establish their own hunting grounds. They grow throughout the summer, feeding on various small insects caught in their orb webs.

Nature of damage: These spiders do not feed on plant tissue, sap, or fruits. They are completely harmless to the physiological integrity of crops. The only interaction with plants is providing structural support for their webs, which can occasionally be an aesthetic nuisance or interfere with precise manual field work.

Harmfulness and agronomic value: In an agronomic context, these spiders are considered beneficial. By consuming flies, aphids, and other small arthropods, they serve as natural pest controllers, helping to keep populations of harmful insects in check. They are an essential part of the natural balance in any garden or nursery.

Protection measures: Chemical control against spiders is not recommended, as it disrupts beneficial predator populations. If their presence in greenhouses becomes excessive, simple management techniques are sufficient:

• Mechanical removal of webs using a brush or broom.
• Maintaining good ventilation, which discourages web construction in specific zones.
• Clearing weed edges where spiders typically anchor their primary web lines.