Understanding Crane Fly Impact in the Pacific Northwest
In the Pacific Northwest, crane flies are becoming an increasingly common threat to commercial landscapes. While these pests may resemble large mosquitoes, their larvae—known as leatherjackets—are the real problem. These larvae feed on grass roots and crowns, causing widespread turf thinning, dead patches, and costly property damage.
For commercial property managers, especially during late summer and fall, early detection and prevention are key to maintaining healthy, attractive turf areas.
What Are Crane Flies?
Crane flies are flying insects that lay eggs in moist turf. Their larvae hatch and begin feeding underground, particularly during cooler, wetter seasons. There are two main types in the PNW:
- European crane fly (Tipula paludosa)
- Marsh crane fly (Tipula oleracea)
In recent years, marsh crane fly activity has increased, leading to longer feeding periods and heavier infestations.
Signs of Crane Fly Damage
Commercial property managers should monitor turf areas closely in late summer through early spring for signs such as:
- Thinning turf or irregular bare patches
- Increased bird activity, especially crows and starlings feeding on larvae
- Spongy turf when walked on
- Poor turf recovery, even with adequate watering
These symptoms often mimic drought stress or disease, so a professional inspection is recommended.
Best Practices for Prevention and Control
While complete eradication is unlikely, property managers can reduce crane fly damage through proactive landscape care. Key strategies include:
1. Seasonal Monitoring
- Schedule turf inspections in late summer and fall, when larvae begin feeding
- Use threshold counts (approx. 25+ larvae per square foot may require treatment)
2. Irrigation Management
- Avoid overwatering, especially in shaded or poorly drained areas
- Promote dry surface soil to reduce crane fly egg-laying
3. Thatch Control
- Dethatch turf to reduce breeding grounds and improve soil health
- Aerate compacted soils to enhance root growth and drainage
4. Overseeding and Turf Repair
- Overseed damaged areas in fall for stronger root systems
- Choose hardy turfgrass varieties with strong recovery rates
5. Targeted Treatment
- Consider professional larvicide applications if populations exceed thresholds
- Time treatments for when larvae are small and most vulnerable
Partner with Monarch for Turf Health Solutions
At Monarch Landscape Companies, we understand the unique challenges facing commercial properties in the Pacific Northwest. Our teams are trained to detect, monitor, and mitigate crane fly damage while improving turf health through seasonal landscape maintenance programs.
We serve a wide range of property types including:
- Corporate campuses
- Commercial real estate portfolios
- Municipal properties and parks
- HOAs and residential communities
Don’t Let Crane Flies Take Over
Crane fly damage can be severe if left unchecked. Stay ahead with a proactive plan that protects your landscape and your investment.
Contact Monarch Landscape Companies to schedule a turf health evaluation or learn more about our seasonal pest prevention programs.
