Wed, 22 Jul 2026 08:38:14 -0700WeeblyWed, 01 Jul 2026 07:43:15 GMThttps://www.ruralaerialcoop.co.nz/blog/porina-dont-wait-until-the-damage-showsPorina can quietly cause significant pasture losses long before obvious damage appears.
By the time bare patches become visible, pasture production has often already been affected for months. 

Why porina are a problem
Porina caterpillars feed at night, pulling pasture material back into their burrows. As populations increase, they create bare patches, reduce pasture quality and compete directly with livestock for feed. 
Heavy infestations can severely impact pasture persistence and productivity.

Know the warning signs
Porina damage is often predictable.
Pastures are commonly at higher risk:

• Two to four years after cultivation or pasture renewal.
• Following drought conditions.
• In paddocks with a history of porina pressure. 

Monitoring moth flights can provide an early warning of future caterpillar populations.
Early action pays
The most successful control programmes happen before damage appears.
Sampling paddocks 8–12 weeks after peak moth flights can help identify populations early and determine whether treatment is worthwhile. 
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Need advice?
If you're concerned about porina pressure on your property, talk to Rural Aerial Co-op about treatment timing and options before pasture production is impacted.]]>