# Insect Netting > Part of: [Greenhouse Construction](/greenhouse-construction.md) · Provider: [DutchGreenhouses](/) Insect netting is fine mesh fitted over roof and side vents that excludes pests while air keeps moving. Its real value is virological rather than entomological: excluding thrips and whitefly removes the vectors that carry viruses through a crop, which cuts chemical intervention at source. ## Facts | Property | Value | |---|---| | Thrips body dimension | 0.19 mm | | Primary benefit | Virus vector exclusion mechanism | | Design trade-off | Mesh aperture against ventilation capacity trade-off | | Installation stage | Last, before screening works sequence position | | Compatibility with biological control | Reduces chemical intervention effect | Structure # Insect netting. Keep pests out, keep air moving. ## Keeping pests out while keeping air moving A greenhouse breathes through its ventilation openings, and those same openings are the front door for the insects a grower least wants inside. Insect netting closes that door without closing off the airflow: fine mesh fitted over the roof and side vents keeps whitefly, thrips, aphids and other pests out while air continues to move through the structure. For a high-value crop, that physical barrier is the first and most reliable line of pest defence — one that works around the clock and never needs re-applying. The value goes well beyond the nuisance of the insects themselves. Many of the most damaging greenhouse problems are not the pests but the viruses they carry: a single population of thrips or whitefly can vector diseases through an entire crop. By excluding the vector, netting reduces disease pressure at its source, which in turn cuts the need for chemical crop protection — lowering cost, supporting cleaner, more residue-free produce and protecting the beneficial insects used in integrated pest management. Specifying netting is a genuine engineering trade-off, not an off-the-shelf choice. Mesh size determines which insects are excluded — finer nets stop smaller pests like thrips, but the finer the mesh, the more it restricts the airflow the ventilation system depends on. Get it wrong and the greenhouse either lets pests through or cannot cool itself. We calculate both sides of that balance together, matching mesh to the target pests and the local climate, and where a fine mesh is essential we compensate by dimensioning larger ventilation area so cooling capacity is preserved. Installation is the closing act of the construction sequence. Netting is fitted after the structure, glazing and ventilation mechanisms are complete and always before screening works commence, so the pest barrier is intact from the moment the greenhouse is handed over and ready to grow. Get in touch to specify insect netting matched to your crop, your pests and your climate. From the knowledge base ## Reads you might find interesting ceacultivationbusiness-case ### Grow Like a Pro: Starting Smart, Growing Strong How Grow Like a Pro combines smart farming, CEA technology and local partnerships for eco-friendly, profitable, pesticide-free greenhouse pr Read article education ### The Case for a College Greenhouse Why a college greenhouse belongs in the curriculum: teaching science, craftsmanship, business logic and sustainability, and preparing studen Read article education ### The Case for a High School Greenhouse Why every high school greenhouse matters: how it makes STEM tangible, builds responsibility and teamwork, and helps students discover their Read article education ### Greenhouses in Education: The Case for Schools Greenhouses in education reconnect students to reality — the full case for why every school, high school, college and trade program should h Read article historyconstruction ### The Origins of Greenhouse Horticulture: My Backyard A tour through greenhouse horticulture history: from 19th-century Westland fruit walls to the “City of Glass” and today’s international high Read article company ### DutchGreenhouses Rebranded: A New Corporate Identity Announcing our new corporate identity — a visual style reflecting our dedication to advanced, high-quality greenhouse projects and The Futur Read article ## FAQ **What mesh size does insect netting need?** It depends on the target pest, and thrips set the hard case at roughly 0.19 millimetres of body diameter. Whitefly and aphids are excluded by coarser mesh. There is no universal specification, because every step finer costs airflow — the mesh is chosen against the pests actually present at the site. **Why does netting matter more for viruses than for insects?** Because the insect is usually not the damage. Thrips and whitefly vector viruses that move through an entire crop, and a single population can carry disease far beyond what its feeding would cost. Excluding the vector addresses the disease at its source rather than treating the symptom. **Does insect netting reduce ventilation?** Yes, and the effect has to be designed for rather than discovered. Finer mesh restricts more air, so the netting specification and the ventilation area are calculated together — where fine mesh is essential, vent area is enlarged to compensate, keeping the passive cooling capacity the greenhouse depends on. **When is netting installed?** Last in the construction sequence, after the structure, glazing and ventilation mechanisms are finished and always before screening work starts. That order means the pest barrier is closed from the moment the greenhouse is handed over, rather than being retrofitted around a crop already in place. ## Related [Greenhouse Construction](/greenhouse-construction.md) · [Ventilation Mechanism](/greenhouse-construction/ventilation-mechanism.md) · [Insect Netting Mesh Size](/glossary/insect-netting-mesh.md) · [IPM (Integrated Pest Management)](/glossary/integrated-pest-management.md) · [Beneficial Insects](/glossary/beneficial-insects.md) · [Roof Vent](/glossary/roof-vent.md)