Common house spider

The common house spider (Parasteatoda tepidariorum) belongs to the order Araneae and the family Theridiidae. It is a highly adaptable species frequently found in greenhouses, nurseries, and indoor agricultural environments, where it exploits stable temperatures and structural features to build its webs.

While Parasteatoda tepidariorum does not feed on crops directly, it functions as an incidental pest in greenhouse systems. As an opportunistic predator, it captures beneficial insects, including predatory wasps and beetles that are intentionally introduced for biological pest control, thus interfering with integrated pest management (IPM) programs.

The life cycle involves the female producing multiple silk egg sacs throughout her lifespan. Under greenhouse conditions, generation times are short, allowing for rapid colonization of the growing area. The spiders utilize structural elements of the facility to anchor their webs, often extending these webs to the canopy of the crops.

The primary damage caused by these spiders is the physical contamination of plants. Their webs collect debris, dust, and fungal spores, which can block sunlight and hinder leaf respiration. Furthermore, heavy webbing can physically damage delicate floral structures or young shoots and makes harvesting and routine maintenance much more difficult.

Effective management strategies to control Parasteatoda tepidariorum include:

• Manual removal of webs and egg sacs during routine greenhouse inspections.
• Modifying the microclimate by optimizing ventilation to reduce humidity levels.
• Installing screens on all greenhouse vents and entry points to exclude adults.
• Removing debris or clutter where spiders can hide and establish colonies.