Protected Cultivation

Insect Exclusion Screening & Airflow Tradeoffs

Screens can reduce pest entry, but finer screening also adds resistance to airflow. Exclusion must therefore be designed together with ventilation capacity, pressure, maintenance, and pest size.

Key concepts

  • Screen aperture determines which pests can be excluded
  • Finer mesh generally creates more airflow resistance
  • Dirty screens progressively reduce airflow
  • Doors, vents, tears, and service openings can defeat otherwise good screening

What to measure or observe

  • Inspect screens for tears and blocked areas
  • Compare vent performance before and after screen installation
  • Record temperature rise during peak ventilation demand
  • Check door and intake pathways for bypass entry

Common mistakes

  • Selecting the finest mesh without evaluating ventilation penalty
  • Installing screens but leaving unscreened bypass routes
  • Failing to clean screens
  • Assuming screening eliminates the need for scouting

Visuals this lesson still needs

  • Mesh-size versus airflow concept chart
  • Screened vent cross section
  • Pest bypass map
  • Screen maintenance checklist

Evidence & further reading

Sources connected to this lesson

These references support specific biological, diagnostic, environmental, or process concepts used in this lesson. They are not a substitute for crop-specific testing or local regulatory guidance.

Connected learning

Use the next piece of evidence

Move between reference material, measurement, field records, and whole-plant context instead of treating one page as the complete answer.